TY - JOUR TI - A trade-off between the frequency and duration of bumblebee visits to flowers AU - Jones, Kristina N. AU - Reithel, Jennifer S. AU - Irwin, Rebecca E. T2 - Oecologia DA - 1998/11/17/ PY - 1998/11/17/ DO - 10.1007/s004420050644 VL - 117 IS - 1-2 SP - 161-168 J2 - Oecologia OP - SN - 0029-8549 1432-1939 UR - http://dx.doi.org/10.1007/s004420050644 DB - Crossref ER - TY - JOUR TI - Nectar robbing in Ipomopsis aggregata  : effects on pollinator behavior and plant fitness AU - Irwin, Rebecca E. AU - Brody, Alison K. T2 - Oecologia DA - 1998/10/1/ PY - 1998/10/1/ DO - 10.1007/s004420050617 VL - 116 IS - 4 SP - 519-527 J2 - Oecologia OP - SN - 0029-8549 1432-1939 UR - http://dx.doi.org/10.1007/s004420050617 DB - Crossref ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes T2 - Applied and Environmental Microbiology DA - 1998/// PY - 1998/// UR - https://publons.com/wos-op/publon/7119238/ ER - TY - JOUR TI - Monitoring for European corn borer (Lepidoptera: Crambidae) resistance to Bacillus thuringiensis: Logistical considerations when sampling larvae AU - Bolin, P.C. AU - Hutchison, W.D. AU - Andow, D.A. AU - Ostlie, K.R. T2 - Journal of Agricultural Entomology DA - 1998/// PY - 1998/// VL - 15 SP - 231–238 ER - TY - CHAP TI - Recommendations for developing and implementing resistance management plans for Bt-toxin-producing crops AU - Gould, F. AU - Tabashnik, B. AU - Hutchison, W. AU - Ferro, D. AU - Andow, D. AU - Whalon, M. T2 - Now or Never: Serious New Plans to Save a Natural Pest Control A2 - Mellon, M. A2 - Rissler, J. PY - 1998/// SP - 13–18 PB - Union of Concerned Scientists ER - TY - CHAP TI - Bt-corn resistance management AU - Andow, D.A. AU - Hutchison, W.D. T2 - Now or Never: Serious New Plans to Save a Natural Pest Control A2 - Mellon, M. A2 - Rissler, J. PY - 1998/// SP - 19–66 PB - Union of Concerned Scientists ER - TY - CHAP TI - Supplement to NCR-602: Bt corn and European corn borer AU - Andow, D.A. T2 - NC-205 PY - 1998/// PB - University of Minnesota ER - TY - JOUR TI - Larval Crowding and Adult Nutrition Effects on Longevity and Fecundity of Female Trichogramma nubilale Ertle & Davis (Hymenoptera: Trichogrammatidae) AU - Olson, D. M. AU - Andow, D. A. T2 - Environmental Entomology AB - The influence of adult feeding of Trichogramma nubilale Ertle & Davis and larval competition within an egg of European corn borer, Ostrinia nubilalis Hübner, on progeny fecundity and longevity was tested. The number and sex of eggs laid were determined through direct observations. Hind tibial lengths were measured on females that were solitary or had shared a host egg with another wasp. Females were separated by size and provided either honey and excess hosts, honey and no hosts, no honey and hosts, or no honey and no hosts each day for their lifetimes. The number of mature eggs at eclosion was determined for several females by dissection of their ovarioles and counting their eggs. The mean hind tibial lengths of solitary females was 0.18 mm, whereas females that had shared a host egg with a male or female had hind tibial lengths of 0.14–0.16 mm. Solitary females had 2.3 times more eggs and lived 1.2 times longer than females that had shared the host with a male or female. Honey increased fecundity by factors of 1.6 and 1.9 and longevity by 5.4 and 4.8 d for solitary females and those that had shared a host egg, respectively. Females that are not fed lay the same number of eggs as estimated from dissected females at eclosion, suggesting that females mature additional eggs only if they are fed as adults. Some implications for inundative releases of T. nubilale against European corn borer in the field are discussed. DA - 1998/4/1/ PY - 1998/4/1/ DO - 10.1093/ee/27.2.508 VL - 27 IS - 2 SP - 508-514 LA - en OP - SN - 1938-2936 0046-225X UR - http://dx.doi.org/10.1093/ee/27.2.508 DB - Crossref ER - TY - JOUR TI - Yield loss in conventional and natural rice farming systems AU - Andow, D.A AU - Hidaka, K T2 - Agriculture, Ecosystems & Environment AB - Compared to modern, conventional agriculture, alternative agricultural production systems may rely on biologically different mechanisms (syndromes) to attain similar production goals. Yield loss to rice in conventional and natural farming rice paddies in Japan was evaluated by simulated injury (leaf-clipping) and monitoring plants damaged by insect herbivores. Rice grown under natural farming practices was more tolerant of simulated injury and injury from Oulema oryzae than rice grown under conventional practices. Natural farming rice retained proportionately more tillers and had a higher proportion of mature seeds than conventionally grown rice. In conventional paddies, the simulated injury may have made the rice plants more susceptible to plant pathogens than their non-injured counterparts, resulting in higher disease attack and proportionately greater yield loss. These results suggest that, pests may affect yield loss independently in natural farming, but in conventional paddies, multiple pest injury may interact synergistically, compounding yield loss. DA - 1998/10// PY - 1998/10// DO - 10.1016/s0167-8809(98)00122-4 VL - 70 IS - 2-3 SP - 151-158 J2 - Agriculture, Ecosystems & Environment LA - en OP - SN - 0167-8809 UR - http://dx.doi.org/10.1016/s0167-8809(98)00122-4 DB - Crossref ER - TY - JOUR TI - Using an F2 Screen to Search for Resistance Alleles to Bacillus thuringiensis Toxin in European Corn Borer (Lepidoptera: Crambidae) AU - Andow, D. A. AU - Alstad, D. N. AU - Pang, Y.H. AU - Bolin, P. C. AU - Hutchison, W. D. T2 - Journal of Economic Entomology AB - We present an application of an F2 screening method for recovering and estimating the frequencies of rare alleles that confer insect resistance to a transgenic corn variety producing Bacillus thuringiensis Berliner crystal protein toxin (Bt corn). Based on a sample of 91 female Ostrinia nubilalis (Hübner) we show with 95% confidence that the frequency of B. thuringiensis resistance alleles from a wild Minnesota population is <0.013. This is an upper limit to the estimated allele frequency and does not provide clear evidence that 1 of the assumptions of the refuge plus high-dose strategy will or will not be met. With additional sampling, a more precise estimate of resistance allele frequency could be obtained that would clearly support or refute 1 of the assumptions of the refuge plus high-dose strategy. Variable costs of the screening method were 19.70per female line, but these could be reduced by improved collecting, rearing, and handling methods. DA - 1998/6/1/ PY - 1998/6/1/ DO - 10.1093/jee/91.3.579 VL - 91 IS - 3 SP - 579-584 LA - en OP - SN - 1938-291X 0022-0493 UR - http://dx.doi.org/10.1093/jee/91.3.579 DB - Crossref ER - TY - JOUR TI - F2 Screen for Rare Resistance Alleles AU - Andow, D. A. AU - Alstad, D. N. T2 - Journal of Economic Entomology AB - Journal Article F2 Screen for Rare Resistance Alleles Get access D. A. Andow, D. A. Andow 1 1Department of Entomology, University of Minnesota, 81.Paul, MN 55108. Search for other works by this author on: Oxford Academic PubMed Google Scholar D. N. Alstad D. N. Alstad 2 2Department of Ecology, Evolution and Behavior, University of Minnesota, 81. Paul, MN 55108. Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 91, Issue 3, 1 June 1998, Pages 572–578, https://doi.org/10.1093/jee/91.3.572 Published: 01 June 1998 DA - 1998/6/1/ PY - 1998/6/1/ DO - 10.1093/jee/91.3.572 VL - 91 IS - 3 SP - 572-578 LA - en OP - SN - 1938-291X 0022-0493 UR - http://dx.doi.org/10.1093/jee/91.3.572 DB - Crossref ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes. AU - Reyes, M. F. AU - Reyes, F. L. AU - Hernandez, M. AU - Raskin, L. T2 - Appl Environ Microbiol DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-12 ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes. AU - Reyes, M. F. AU - Reyes, F. L. AU - Hernandez, M. AU - Raskin, L. T2 - Appl Environ Microbiol DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-12 ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes AU - Reyes, MF AU - Reyes, FL AU - Hernandez, M AU - Raskin, L T2 - Applied and Environmental Microbiology DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-2512 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000074644700028&KeyUID=WOS:000074644700028 ER - TY - RPRT TI - Study on morphological characteristics of rice, wheat, oil seed rape, onion, broad leaf mustard and radish varieties, 1996 AU - Panthee, D.R. A3 - Lumle Agricultural Research Centre DA - 1998/// PY - 1998/// M1 - 98/2 M3 - LARC Working Paper PB - Lumle Agricultural Research Centre SN - 98/2 ER - TY - RPRT TI - Identification of the parents for the production of bacterial wilt tolerant and high yielding hybrids of tomato (Lycopersicon esculentum AU - Panthee, D.R. AU - Bhattarai, S.P. A3 - Lumle Agricultural Research Center DA - 1998/// PY - 1998/// M1 - 98/23 M3 - LARC Working Paper PB - Lumle Agricultural Research Center SN - 98/23 ER - TY - RPRT TI - Effect of threshing, cleaning and drying period on onion seed viability AU - Panthee, D.R. AU - Subedi, P.P. A3 - Lumle Agricultural Research Centre DA - 1998/// PY - 1998/// M1 - 98/18 M3 - LARC Working Paper PB - Lumle Agricultural Research Centre SN - 98/18 ER - TY - RPRT TI - Stability analysis of potato varieties AU - Panthee, D.R. AU - Dhital, B.K. AU - Budhathoki, C.B. A3 - Lumle Agricultural Research Center DA - 1998/// PY - 1998/// M1 - 98/13 M3 - LARC Seminar Paper PB - Lumle Agricultural Research Center SN - 98/13 ER - TY - RPRT TI - Rice varietal improvement research for low-hills carried out at LARC during 1995 AU - Panthee, D.R. AU - Bhandari, H.S. AU - Sah, R.P. A3 - Lumle Agricultural Research Center DA - 1998/// PY - 1998/// M1 - 98/11 M3 - LARC Working Paper PB - Lumle Agricultural Research Center SN - 98/11 ER - TY - JOUR TI - Detection of Putative Loci Affecting Conformational Type Traits in an Elite Population of United States Holsteins Using Microsatellite Markers AU - Ashwell, M.S. AU - Da, Y. AU - Vanraden, P.M. AU - Rexroad, C.E., Jr. AU - Miller, R.H. T2 - Journal of Dairy Science AB - Quantitative trait loci affecting conformational type traits were studied in seven large grandsire families of US Holsteins using the granddaughter design and 16 microsatellite markers on 10 chromosomes. The most significant marker effect was marker BM203 (chromosome 27) for dairy form in a single grandsire family. A multivariate analysis for dairy form and milk yield was also conducted, and the result was highly significant, indicating that a segregating quantitative trait locus or loci affecting dairy form and milk yield could exist near BM203 on chromosome 27. Marker BM1258 (chromosome 23) had a significant effect on udder depth. A multivariate analysis on udder depth and somatic cell score was conducted for markers 513 and BM1258, and both markers showed significant effects on these two traits, indicating that one or several quantitative trait loci affecting udder depth and mastitis might exist on chromosome 23. Marker BM4204 (chromosome 9) had a significant effect on foot angle and on the composite index of traits pertaining to feet and legs, indicating that one or several quantitative trait loci affecting traits pertaining to feet and legs might exist on chromosome 9. Selection on these markers could increase genetic progress within these families. DA - 1998/4// PY - 1998/4// DO - 10.3168/jds.s0022-0302(98)75674-7 VL - 81 IS - 4 SP - 1120-1125 J2 - Journal of Dairy Science LA - en OP - SN - 0022-0302 UR - http://dx.doi.org/10.3168/jds.s0022-0302(98)75674-7 DB - Crossref ER - TY - JOUR TI - Detection of Putative Loci Affecting Milk Production and Composition, Health, and Type Traits in a United States Holstein Population AU - Ashwell, M.S. AU - Da, Y. AU - Van Tassell, C.P. AU - Vanraden, P.M. AU - Miller, R.H. AU - Rexroad, C.E., Jr. T2 - Journal of Dairy Science AB - Quantitative trait loci affecting milk yield and composition, health, and type traits were studied for seven large grandsire families of US Holstein using the granddaughter design. The families were genotyped at 20 microsatellite markers on 15 chromosomes, and the effects of the marker alleles were analyzed for 28 traits (21 type traits, 5 milk yield and composition traits, somatic cell score, and productive herd life). Markers BM415 on chromosome 6 and BM6425 on chromosome 14 were associated with effects on protein percentage in a single grandsire family. The latter marker had a lower probability of being associated with changes in milk yield and fat percentage in the same family. Increases in productive herd life were associated with an allele at marker BM719 on chromosome 16 in one grandsire family. DA - 1998/12// PY - 1998/12// DO - 10.3168/jds.s0022-0302(98)75896-5 VL - 81 IS - 12 SP - 3309-3314 J2 - Journal of Dairy Science LA - en OP - SN - 0022-0302 UR - http://dx.doi.org/10.3168/jds.s0022-0302(98)75896-5 DB - Crossref KW - quantitative trait loci KW - microsatellite markers KW - milk yield traits KW - type traits ER - TY - CONF TI - Artemisia annua L. Transformation with different Agrobacterium rhizogenesis and large scale culture of hairy roots for Artemisinin (Qinghaosu) production AU - Xie, Deyu AU - Ye, Hechun AU - Li, Guofeng AU - Guo, Zhongchen A2 - Larkin, P.J. C2 - 1998/// C3 - Agricultural biotechnology : laboratory, field and market : proceedings of the 4th Asia-Pacific Conference on Agricultural Biotechnology, 13-16 July 1998, Darwin, Australia DA - 1998/// SP - 134–136 PB - Under the Counter Publishing ER - TY - CONF TI - Shewhart Charting Applied to the Growth of Pig Populations AU - Roberts, J. AU - Deen, J. AU - Levine, J.F. AU - Almond, G.W. T2 - International Pig Veterinary Society C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - CHAP TI - Pyrococcus furiosus Protease I (PfpI) AU - Hicks, P.M. AU - Kelly, R.M. T2 - Handbook of Proteolytic Enzymes A2 - Woessner, F. A2 - Rawlings, N. A2 - Barrett, A. PY - 1998/// PB - Academic Press Limited ER - TY - CHAP TI - Obstructive conditions of the large intestine AU - Jones, S.L. AU - Snyder, J.R. AU - Spier, S. T2 - Equine Internal Medicine A2 - Bayly, W. A2 - Reed, S. PY - 1998/// SP - 682–694 PB - WB Saunders SN - 9780721635248 ER - TY - CHAP TI - Inflammatory diseases of the large intestine causing diarrhea AU - Jones, S.L. AU - Spier, S. T2 - Equine Internal Medicine A2 - Bayly, W. A2 - Reed, S. PY - 1998/// SP - 663–682 PB - WB Saunders SN - 9780721635248 ER - TY - CHAP TI - Pathophysiology of colonic inflammation and diarrhea AU - Jones, S.L. AU - Spier, S. A2 - Bayly, W. A2 - Reed, S. PY - 1998/// SP - 660–663 PB - WB Saunders SN - 9780721635248 ER - TY - CHAP TI - Examination for disorders of the large intestine AU - Jones, S.L. AU - Snyder, J.R. AU - Spier, S. T2 - Equine Internal Medicine A2 - Bayly, W. A2 - Reed, S. PY - 1998/// SP - 655–660 PB - WB Saunders SN - 9780721635248 ER - TY - CHAP TI - Physiology of the large intestine AU - Jones, S.L. AU - Snyder, J.R. AU - Spier, S. T2 - Equine internal medicine A2 - Bayly, W. A2 - Reed, S. PY - 1998/// SP - 651–655 PB - WB Saunders SN - 9780721635248 ER - TY - CHAP TI - Pathophysiology of intestinal injury AU - Jones, S.L. AU - Snyder, J.R. AU - Spier, S. T2 - Equine Internal Medicine A2 - Bayly, W. A2 - Reed, S. PY - 1998/// SP - 636-639 PB - WB Saunders SN - 9780721635248 ER - TY - JOUR TI - Caspar Carboxylates: The Structural Basis of Tobamovirus Disassembly AU - Wang, Hong AU - Planchart, Antonio AU - Stubbs, Gerald T2 - Biophysical Journal AB - Carboxylate groups have been known for many years to drive the disassembly of simple viruses, including tobacco mosaic virus (TMV). The identities of the carboxylate groups involved and the mechanism by which they initiate disassembly have not, however, been clear. Structures have been determined at resolutions between 2.9 and 3.5 A for five tobamoviruses by fiber diffraction methods. Site-directed mutagenesis has also been used to change numerous carboxylate side chains in TMV to the corresponding amides. Comparison of the stabilities of the various mutant viruses shows that disassembly is driven by a much more complex set of carboxylate interactions than had previously been postulated. Despite the importance of the carboxylate interactions, they are not conserved during viral evolution. Instead, it appears that during evolution, patches of electrostatic interaction drift across viral subunit interfaces. The flexibility of these interactions confers a considerable advantage on the virus, enabling it to change its surface structure rapidly and thus evade host defenses. DA - 1998/1// PY - 1998/1// DO - 10.1016/S0006-3495(98)77822-1 VL - 74 IS - 1 SP - 633-638 J2 - Biophysical Journal LA - en OP - SN - 0006-3495 UR - http://dx.doi.org/10.1016/S0006-3495(98)77822-1 DB - Crossref ER - TY - JOUR TI - Interplanting Wheat Is Not an Effective Postplant Management Tactic for Criconemella xenoplaxin Peach Production AU - Nyczepir, A. P. AU - Bertrand, P. F. AU - Parker, M. L. AU - Meyer, J. R. AU - Zehr, E. I. T2 - Plant Disease AB - In two orchard experiments, interplanting wheat (Triticum aestivum cv. Stacy) around either newly planted or 4-year-old well-established peach trees did not suppress (P ≤ 0.05) the population density of the ring nematode, Criconemella xenoplax, after 3 years. Furthermore, inter-planting wheat around newly planted trees reduced tree growth, perhaps the result of competition for water and (or) nutrients. Wheat root exudate was not as attractive to C. xenoplax as peach root exudate, but wheat root exudate did not repel the nematode either. Stacy wheat appeared to be more beneficial as a preplant rather than as a postplant ground cover management tool for suppressing the population density of C. xenoplax. DA - 1998/5// PY - 1998/5// DO - 10.1094/pdis.1998.82.5.573 VL - 82 IS - 5 SP - 573–577 SN - 0191-2917 UR - http://dx.doi.org/10.1094/pdis.1998.82.5.573 KW - cultural control KW - Prunus persica KW - short life ER - TY - JOUR TI - Investigation on the Medical Plant Resources of Beizhang Experimental Area in the Upper Reaches of Miyun Reservoir AU - Li, G. AU - Zhang, Y. AU - Wang, J. AU - Liu, W. T2 - Quarterly of Forest By-Product And Speciality in China DA - 1998/// PY - 1998/// VL - 2 SP - 45–46 ER - TY - RPRT TI - Salmonella Enteritidis Risk Assessment: Shell Eggs and Egg Products AU - Kuzma, J. A3 - USDA Food Safety and Inspection Service DA - 1998/6// PY - 1998/6// M3 - Salmonella I Enteritidis Risk Assessment Team Final Report PB - USDA Food Safety and Inspection Service ER - TY - JOUR TI - Identification of sucrose synthase as an actin-binding protein AU - Winter, H. AU - L. Huber, J. AU - Huber, S.C. T2 - FEBS Letters AB - Several lines of evidence indicate that sucrose synthase (SuSy) binds both G- and F-actin: (i) presence of SuSy in the Triton X-100-insoluble fraction of microsomal membranes (i.e. crude cytoskeleton fraction); (ii) co-immunoprecipitation of actin with anti-SuSy monoclonal antibodies; (iii) association of SuSy with in situ phalloidin-stabilized F-actin filaments; and (iv) direct binding to F-actin, polymerized in vitro. Aldolase, well known to interact with F-actin, interfered with binding of SuSy, suggesting that a common or overlapping binding site may be involved. We postulate that some of the soluble SuSy in the cytosol may be associated with the actin cytoskeleton in vivo. DA - 1998/// PY - 1998/// DO - 10.1016/S0014-5793(98)00659-0 VL - 430 IS - 3 SP - 205-208 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0032479338&partnerID=MN8TOARS KW - actin-binding protein KW - actin cytoskeleton KW - aldolase KW - sucrose synthase KW - phalloidin ER - TY - JOUR TI - Growth dynamics and cytoskeleton organization during stem maturation and gravity-induced stem bending in Zea mays L. AU - Collings, D.A. AU - Winter, H. AU - Wyatt, S.E. AU - Allen, N.S. T2 - Planta DA - 1998/// PY - 1998/// DO - 10.1007/s004250050480 VL - 207 IS - 2 SP - 246-258 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0032435367&partnerID=MN8TOARS KW - actin KW - cell elongation KW - gravitropism KW - microtubule KW - pulvinus KW - Zea (gravitropism) ER - TY - JOUR TI - EFFECTS OF GROWTH HORMONE AND PAIR-FEEDING ON LEPTIN mRNA EXPRESSION IN LIVER AND ADIPOSE TISSUE OF BROILER CHICKENS AU - Ashwell, C AU - McMurtry, J AU - Wang, XH AU - Zhou, Y AU - Vasilatos-Younken, R T2 - BIOTECHNOLOGIE AGRONOMIE SOCIETE ET ENVIRONNEMENT DA - 1998/// PY - 1998/// VL - 2 SP - 45-45 ER - TY - JOUR TI - Changes in body composition and adipocyte cellularity of male broilers subjected to varying degrees early-life feed restriction. AU - Benyi, K AU - Acheampong-Boateng, O AU - Norris, D AU - Mikasi, MS AU - Altan, O AU - Ozkan, S AU - Yakin, S AU - Appleby, MC AU - Hughes, BO AU - Elson, HA AU - others T2 - Asian Journal of Animal and Veterinary Advances DA - 1998/// PY - 1998/// VL - 3 IS - 4 SP - 321-326 ER - TY - JOUR TI - Turkey leptin (ob) mRNA, partial cds AU - Ashwell, CM AU - Czerwinski, SM AU - McMurtry, JP T2 - GenBank Accession Number AF082501 DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Investigations into the nature of signal peptidase substrate interactions. AU - Ashwell, Christopher M DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Cloning of turkey insulin-like growth factor-I (IGF-I) AU - Czerwinski, SM AU - Ashwell, CM AU - McMurtry, JP T2 - DNA database DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Recombination values for the Ms6-W1 chromosome region in different genetic backgrounds in soybean AU - Palmer, R.G. AU - Holland, J.B. AU - Lewers, K.S. T2 - Crop Science DA - 1998/// PY - 1998/// VL - 38 IS - 2 SP - 293-296 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031811862&partnerID=MN8TOARS ER - TY - JOUR TI - Inheritance of resistance to southern corn rust in tropical-by-corn-belt maize populations AU - Holland, J.B. AU - Uhr, D.V. AU - Jeffers, D. AU - Goodman, M.M. T2 - Theoretical and Applied Genetics DA - 1998/// PY - 1998/// DO - 10.1007/s001220050732 VL - 96 IS - 2 SP - 232-241 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031956880&partnerID=MN8TOARS KW - Puccinia polysora KW - RFLP markers KW - partial resistance ER - TY - JOUR TI - EPISTACY: A SAS program for detecting two-locus epistatic interactions using genetic marker information AU - Holland, J.B. T2 - Journal of Heredity DA - 1998/// PY - 1998/// DO - 10.1093/jhered/89.4.374 VL - 89 IS - 4 SP - 374-375 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031817262&partnerID=MN8TOARS ER - TY - JOUR TI - Chronic Trypanosoma cruzi infection in dogs: 11 cases (1987–1996) AU - Meurs, K.M. AU - Anthony, M.A. AU - Slater, M. AU - Miller, M.W. T2 - Journal of the American Veterinary Medical Association DA - 1998/// PY - 1998/// VL - 213 IS - 4 SP - 497-500 ER - TY - JOUR TI - Detecting Marker-Disease Association by Testing for Hardy-Weinberg Disequilibrium at a Marker Locus AU - Nielsen, Dahlia M. AU - Ehm, M.G. AU - Weir, B.S. T2 - The American Journal of Human Genetics AB - We review and extend a recent suggestion that fine-scale localization of a disease-susceptibility locus for a complex disease be done on the basis of deviations from Hardy-Weinberg equilibrium among affected individuals. This deviation is driven by linkage disequilibrium between disease and marker loci in the whole population and requires a heterogeneous genetic basis for the disease. A finding of marker-locus Hardy-Weinberg disequilibrium therefore implies disease heterogeneity and marker-disease linkage disequilibrium. Although a lack of departure of Hardy-Weinberg disequilibrium at marker loci implies that disease susceptibilityweighted linkage disequilibria are zero, given disease heterogeneity, it does not follow that the usual measures of linkage disequilibrium are zero. For disease-susceptibility loci with more than two alleles, therefore, care is needed in the drawing of inferences from marker Hardy-Weinberg disequilibria. DA - 1998/11// PY - 1998/11// DO - 10.1086/302114 VL - 63 IS - 5 SP - 1531-1540 J2 - The American Journal of Human Genetics LA - en OP - SN - 0002-9297 UR - http://dx.doi.org/10.1086/302114 DB - Crossref ER - TY - JOUR TI - Intragenic Recombination and Diversifying Selection Contribute to the Evolution of Downy Mildew Resistance at the RPP8 Locus of Arabidopsis AU - McDowell, J.M. AU - Dhandaydham, M. AU - Long, T.A. AU - Aarts, M.G.M. AU - Goff, S. AU - Holub, E.B. AU - Dangl, J.L. T2 - The Plant Cell AB - Pathogen resistance (R) genes of the NBS-LRR class (for nucleotide binding site and leucine-rich repeat) are found in many plant species and confer resistance to a diverse spectrum of pathogens. Little is known about the mechanisms that drive NBS-LRR gene evolution in the host-pathogen arms race. We cloned the RPP8 gene (for resistance to Peronospora parasitica) and compared the structure of alleles at this locus in resistant Landsberg erecta (Ler-0) and susceptible Columbia (Col-0) accessions. RPP8-Ler encodes an NBS-LRR protein with a putative N-terminal leucine zipper and is more closely related to previously cloned R genes that confer resistance to bacterial pathogens than it is to other known RPP genes. The RPP8 haplotype in Ler-0 contains the functional RPP8-Ler gene and a nonfunctional homolog, RPH8A. In contrast, the rpp8 locus in Col-0 contains a single chimeric gene, which was likely derived from unequal crossing over between RPP8-Ler and RPH8A ancestors within a Ler-like haplotype. Sequence divergence among RPP8 family members has been accelerated by positive selection on the putative ligand binding region in the LRRs. These observations indicate that NBS-LRR molecular evolution is driven by the same mechanisms that promote rapid sequence diversification among other genes involved in non-self-recognition. DA - 1998/11// PY - 1998/11// DO - 10.1105/tpc.10.11.1861 VL - 10 IS - 11 SP - 1861-1874 UR - http://dx.doi.org/10.1105/tpc.10.11.1861 ER - TY - JOUR TI - Insights into the Hereditability of Canine Cardiomyopathy AU - Meurs, Kathryn M. T2 - Veterinary Clinics of North America: Small Animal Practice AB - There is evidence for a genetic etiology of dilated cardiomyopathy in at least two breeds, the Doberman pinscher and the Boxer dog. Significant effort toward determining a genetic etiology in these breeds will depend on careful characterization of the disease, determination of criteria for diagnosing asymptomatic affected individuals, determination of a pattern of inheritance, and, eventually, molecular evaluation of the specific gene. DA - 1998/11// PY - 1998/11// DO - 10.1016/s0195-5616(98)50131-3 VL - 28 IS - 6 SP - 1449-1457 J2 - Veterinary Clinics of North America: Small Animal Practice LA - en OP - SN - 0195-5616 UR - http://dx.doi.org/10.1016/s0195-5616(98)50131-3 DB - Crossref ER - TY - JOUR TI - Sites of synthesis and transport pathways of insect hydrocarbons: Cuticle and ovary as target tissues AU - SCHAL, C AU - SEVALA, VL AU - YOUNG, HP AU - BACHMANN, JAS T2 - AMERICAN ZOOLOGIST DA - 1998/// PY - 1998/// VL - 38 IS - 2 SP - 382-393 ER - TY - JOUR TI - Productivity and water use efficiency of sweet sorghum as affected by soil water deficit occurring at different vegetative growth stages. AU - Pholsen, S AU - Kasikranan, S AU - Pholsen, P AU - Suksri, A AU - Pholsen, S AU - Higgs, DEB AU - Suksri, A AU - Phaikaew, C AU - Boonpukdee, W AU - Srakoopan, S AU - others T2 - Pakistan Journal of Biological Sciences DA - 1998/// PY - 1998/// VL - 7 IS - 4 SP - 228-231 ER - TY - CHAP TI - Comparison of commercial fertilizer and organic by-products on soil chemical and biological properties and vegetable yields AU - Brosius, MR AU - Evanylo, GK AU - Bulluck, LR AU - Ristaino, JB T2 - Beneficial Co-Utilization of Agricultural, Municipal and Industrial by-Products PY - 1998/// SP - 195-202 PB - Springer, Dordrecht ER - TY - JOUR TI - PCR assays for phytophthora species AU - Ristaino, Jean B DA - 1998/7// PY - 1998/7// N1 - US Patent 5,780,271 RN - US Patent 5,780,271 ER - TY - JOUR TI - Nuclear events in ethylene signaling: A transcriptional cascade mediated by ETHYLENE-INSENSITIVE3 and ETHYLENE-RESPONSE-FACTOR1 AU - Solano, R. AU - Stepanova, A. AU - Chao, Q. AU - Ecker, J.R. T2 - Genes and Development AB - Response to the gaseous plant hormone ethylene in Arabidopsis requires the EIN3/EIL family of nuclear proteins. The biochemical function(s) of EIN3/EIL proteins, however, has remained unknown. In this study, we show that EIN3 and EILs comprise a family of novel sequence-specific DNA-binding proteins that regulate gene expression by binding directly to a primary ethylene response element (PERE) related to the tomato E4-element. Moreover, we identified an immediate target of EIN3, ETHYLENE-RESPONSE-FACTOR1 (ERF1), which contains this element in its promoter. EIN3 is necessary and sufficient for ERF1 expression, and, like EIN3-overexpression in transgenic plants, constitutive expression of ERF1 results in the activation of a variety of ethylene response genes and phenotypes. Evidence is also provided that ERF1 acts downstream of EIN3 and all other components of the ethylene signaling pathway. The results demonstrate that the nuclear proteins EIN3 and ERF1 act sequentially in a cascade of transcriptional regulation initiated by ethylene gas. DA - 1998/// PY - 1998/// DO - 10.1101/gad.12.23.3703 VL - 12 IS - 23 SP - 3703-3714 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0032417391&partnerID=MN8TOARS KW - plants KW - Arabidopsis KW - EIN3 KW - ERF1 KW - transcription ER - TY - JOUR TI - The importance of archival and herbarium materials in understanding the role of oospores in late blight epidemics of the past AU - Ristaino, J.B. T2 - Phytopathology DA - 1998/// PY - 1998/// VL - 88 IS - 11 SP - 1120-1130 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031758195&partnerID=MN8TOARS ER - TY - JOUR TI - Non-autonomous regulation of a graded, PKA-mediated transcriptional activation signal for cell patterning AU - Balint-Kurti, P. AU - Ginsburgt, G.T. AU - Liu, J. AU - Kimmel, A.R. T2 - Development DA - 1998/// PY - 1998/// VL - 125 IS - 20 SP - 3947-3954 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031792681&partnerID=MN8TOARS ER - TY - CHAP TI - Plant P-Hydroxyphenylpyruvate Dioxygenase: A Target for New Bleaching Herbicides AU - Garcia, I. AU - Rodgers, M. AU - Pépin, R. AU - Hsieh, Tzung-Fu AU - Matringe, M. T2 - Photosynthesis: Mechanisms and Effects PY - 1998/// DO - 10.1007/978-94-011-3953-3_900 SP - 3861-3864 OP - PB - Springer Netherlands SN - 9780792355472 9789401139533 UR - http://dx.doi.org/10.1007/978-94-011-3953-3_900 DB - Crossref ER - TY - JOUR TI - Electrolyte disturbances in foals with severe rhabdomyolysis. AU - Perkins, G AU - Valberg, SJ AU - Madigan, JM AU - Carlson, GP AU - Jones, SL T2 - Journal of veterinary internal medicine DA - 1998/// PY - 1998/// VL - 12 IS - 3 SP - 173–177, UR - http://europepmc.org/abstract/med/9595379 ER - TY - JOUR TI - Storage life of onion seeds in relation to the methods of threshing and cleaning, and drying period AU - Panthee, D.R. T2 - Nepalese Horticulture DA - 1998/// PY - 1998/// VL - 2 SP - 31–36 ER - TY - JOUR TI - Evaluating the performance of tomato (Lycopersicon esculentum Mill.) cultivars for genetic transformation AU - Panthee, D.R. AU - Newbury, H.J. T2 - Nepal Agriculture Research Journal DA - 1998/// PY - 1998/// VL - 2 SP - 48–54 ER - TY - JOUR TI - Effect of genotype, medium and explant on callus production and in vitro regeneration of tomato (Lycopersicon esculentum Mill.) AU - Panthee, D.R. AU - Newbury, H.J. T2 - Nepal Agriculture Research Journal DA - 1998/// PY - 1998/// VL - 2 SP - 20–26 ER - TY - CONF TI - Propagation of Magnolia virginiana ‘Santa Rosa’ by semihardwood cuttings AU - Griffin, J.J. AU - Blazich, F.A. AU - Ranney, T.G. C2 - 1998/// C3 - Proceedings of the Southern Nursery Association Research Conference, 43rd Annual Report DA - 1998/// SP - 340–343 ER - TY - JOUR TI - Spatial Variability in In Situ Aerobic Respiration and Denitrification Rates in a Petroleum-Contaminated Aquifer AU - Schroth, M. H. AU - Istok, J. D. AU - Conner, G. T. AU - Hyman, M. R. AU - Haggerty, R. AU - O'Reilly, K. T. T2 - Groundwater AB - Abstract An extensive series of single‐well, push‐pull tests was performed to quantify horizontal and vertical spatial variability in aerobic respiration and denitrification rates in a petroleum‐contaminated aquifer. The results indicated rapid consumption of injected O 2 or NO 3 − in shallow and deep test intervals across a large portion of the site. Computed first‐order rate coefficients for aerobic respiration ranged from 0.15 to 1.69 h −1 in the shallow test interval, and from 0.08 to 0.83 h −1 in the deep test interval. The largest aerobic respiration rates occurred on the upgradient edge of the contaminant plume where concentrations of petroleum hydrocarbons and dissolved O 2 were relatively high. Computed first‐order rate coefficients for denitrification ranged from 0.09 to 0.42 h −1 in the shallow test interval, and from 0.11 to 0.28 h −1 in the deep test interval. The largest denitrification rates occurred on the downgradient edge of the plume where hydrocarbon concentrations were relatively high but dissolved oxygen concentrations were small. The rates reported here represent maximal rates of aerobic respiration and denitrification, as supported by high concentrations of electron acceptors in the injected test solutions. Production of dissolved CO 2 during aerobic respiration and denitrification tests provided evidence that O 2 and NO 3 − consumption was largely due to microbial activity. Additional evidence for microbial NO 3 − consumption was provided by reduced rates of NO 3 − consumption when dissolved O 2 was injected with NO 3 − , and by increased N 2 O production when C 2 H 2 was injected with NO 3 − . DA - 1998/// PY - 1998/// DO - 10.1111/j.1745-6584.1998.tb02099.x VL - 36 IS - 6 SP - 924-937 LA - en SN - 1745-6584 UR - https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1745-6584.1998.tb02099.x DB - Wiley Online Library Y2 - 2019/2/1/ ER - TY - CHAP TI - rbcL sequence divergence and phylogenetic relationships of Cornaceae sensu lato AU - Xiang, Q.-Y. AU - Soltis, D.E. T2 - Sino-Japanese Flora - Its Characteristics and Diversification A2 - Boufford, D.E. A2 - Ohba, H. PY - 1998/// SP - 123–139 PB - The University of Tokyo Press ER - TY - JOUR TI - Molecular evidence for origins of polyploid Saxifraga (Saxifragaceae): the narrow arctic endemic S. svalbardensis and its widespread allies AU - Brochmann, C. AU - Xiang, Q.Y. AU - Brunsfeld, S.J. AU - Soltis, D.E. AU - Soltis, P.S. T2 - American Journal of Botany AB - The recently described polyploid Saxifraga svalbardensis is endemic to the arctic archipelago of Svalbard. We investigated relationships among four closely related species of Saxifraga in Svalbard and tested three previously proposed hypotheses for the origin of S. svalbardensis : (1) differentiation from the morphologically and chromosomally variable polyploid S. cernua; (2) hybridization between the diploid S. hyperborea and S. cernua; and (3) hybridization between the tetraploid S. rivularis and S. cernua . Fifteen populations were analyzed using random amplified polymorphic DNAs (RAPDs) and nucleotide sequences of the chloroplast gene matK and the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA). RAPD and matK data suggest that S. svalbardensis has originated from a hybrid with S. rivularis as the maternal parent and S. cernua as the paternal parent, possibly a single time, whereas ITS data could not be used to discriminate among the hypotheses. The data also suggest that the diploid S. hyperborea is a progenitor of the tetraploid S. rivularis . The four populations examined of S. svalbardensis were virtually identical for RAPD and ITS markers, whereas S. cernua showed high levels of variation, suggesting that the latter polyploid either has formed recurrently or has undergone considerable differentiation since its origin. DA - 1998/// PY - 1998/// DO - 10.2307/2446562 VL - 85 SP - 135–143 KW - Arctic KW - sequences KW - matK nucleotide sequences KW - polyploid evolution KW - RAPDs KW - Saxifraga cernua KW - Saxifraga svalbardensis KW - Saxifragaceae ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes. AU - Reyes, M. F. AU - Reyes, F. L. AU - Hernandez, M. AU - Raskin, L. T2 - Appl Environ Microbiol DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-12 ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes. AU - Reyes, M. F. AU - Reyes, F. L. AU - Hernandez, M. AU - Raskin, L. T2 - Appl Environ Microbiol DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-12 ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes T2 - Applied and Environmental Microbiology DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-2512 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031844804&partnerID=MN8TOARS ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes AU - Reyes, MF AU - Reyes, FL AU - Hernandez, M AU - Raskin, L T2 - Applied and Environmental Microbiology DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-2512 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000074644700028&KeyUID=WOS:000074644700028 ER - TY - JOUR TI - Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes AU - Delos Reyes, M. Fiorella AU - De Los Reyes, Francis L., III AU - Hernandez, Mark AU - Raskin, Lutgarde T2 - Applied and Environmental Microbiology DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2503-2512 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=BIOSIS&KeyUT=BIOSIS:PREV199800364592&KeyUID=BIOSIS:PREV199800364592 ER - TY - JOUR TI - Identification and quantification of Gordona amarae strains in activated sludge systems using comparative rRNA sequence analysis and phylogenetic hybridization probes AU - Los Reyes, M. Fiorella AU - De Los Reyes, Francis L. AU - Hernandez, Mark AU - Raskin, Lutgarde T2 - Water Science and Technology DA - 1998/// PY - 1998/// VL - 37 IS - 4-5 SP - 521-525 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=BCI&KeyUT=BCI:BCI199800324175&KeyUID=BCI:BCI199800324175 ER - TY - JOUR TI - Identification and quantification of Gordona amarae strains in activated sludge systems using comparative rRNA sequence analysis and phylogenetic hybridization probes AU - Reyes, MF AU - Reyes, FL AU - Hernandez, M AU - Raskin, L T2 - Water Science and Technology AB - Small subunit (SSU) ribosomal RNA (rRNA) genes of four Gordona ( Nocardia ) amarae strains were sequenced and compared to the sequence of the G. amarae type strain obtained from the Ribosomal Database Project (RDP). Comparative sequence analysis showed that the five strains represent two lines of evolutionary descent: Group 1 consists of strains NM23 and ASAC1 and Group 2 contains strains SE-6, SE102, and ASF3. To determine the abundance of G. amarae in activated sludge systems, we designed three oligonucleotide probes: a species-specific probe for G. amarae , a probe specific for Group 1 and a probe targeting Group 2. The probes were characterized by performing dissociation temperature and specificity studies. Using these probes, two other strains, strains SE-149B and RBI, also were found to be part of Group 1. We used these probes along with previously designed probes in membrane hybridizations to determine the abundance of G. amarae , Group 1, Group 2, Bacteria, Mycobacterium complex, and Gordona in samples from foaming episodes. We demonstrated that the Mycobacterium complex, the genus Gordona , and G. amarae strains were present in significantly greater concentrations in activated sludge foam than in mixed liquor. DA - 1998/// PY - 1998/// DO - 10.1016/S0273-1223(98)00154-1 VL - 37 IS - 4-5 SP - 521-525 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000073933300082&KeyUID=WOS:000073933300082 ER - TY - JOUR TI - Characterization of filamentous foaming in activated sludge systems using oligonucleotide hybridization probes and antibody probes AU - Los Reyes, Francis L., III AU - Oerther, Daniel B. AU - De Los Reyes, M. Fiorella AU - Hernandez, Mark AU - Raskin, Lutgarde T2 - Water Science and Technology DA - 1998/// PY - 1998/// VL - 37 IS - 4-5 SP - 485-493 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=BCI&KeyUT=BCI:BCI199800324173&KeyUID=BCI:BCI199800324173 ER - TY - JOUR TI - Characterization of filamentous foaming in activated sludge systems using oligonucleotide hybridization probes and antibody probes AU - Reyes, FL AU - Oerther, DB AU - Reyes, MF AU - Hernandez, M AU - Raskin, L T2 - Water Science and Technology AB - A quantitative method was developed for estimating Gordona mass in activated sludge foam and mixed liquor samples. The technique involves in situ hybridization with a genus-specific fluorescently labeled oligonucleotide probe calibrated on pure cultures of Gordona . The immunofluorescent technique of Hernandez et al. was modified to allow staining with fluorescently labeled antibody and hybridization probes. The results of this technique were compared to those from membrane hybridization studies using radioactively-labeled oligonucleotide probes. Quantitative membrane hybridizations, in situ hybridizations, and antibody staining resulted in significantly different levels of Gordona in activated sludge foam, activated sludge mixed liquor, return activated sludge, and anaerobic digester sludge. Simultaneous staining with labeled antibodies and oligonucleotide probes provide a definitive identification for Gordona , and represents a new approach for in situ studies of this organism9s role in foaming. DA - 1998/// PY - 1998/// DO - 10.1016/S0273-1223(98)00150-4 VL - 37 IS - 4-5 SP - 485-493 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000073933300078&KeyUID=WOS:000073933300078 ER - TY - JOUR TI - Interleukin-12 Overcomes Paclitaxel-Mediated Suppression of T-Cell Proliferation AU - Mullins, David W. AU - Koci, Matthew D. AU - Burger, Carol J. AU - Elgert, Klaus D. T2 - Immunopharmacology and Immunotoxicology AB - The antineoplastic agent paclitaxel (TAXOL) is a potent inhibitor of tumor cell division and a useful chemotherapeutic for the treatment of refractory ovarian and breast carcinoma. Multiple immune system actions have been ascribed to paclitaxel, including the capacity to induce macrophage antitumor cytotoxic molecule production. However, T-cells are susceptible to paclitaxel's cytostatic functions, and no studies have investigated the effects of direct paclitaxel administration on lymphocyte function in the tumor-bearing host (TBH). Because paclitaxel is currently used as an antitumor chemotherapeutic agent and tumor growth alters leukocyte functions, we assessed T-cell function following chemotherapeutic-type paclitaxel treatment. Paclitaxel administration significantly compromised the proliferative capacity of both normal host and TBH lymphocytes in vitro. Although tumor growth impaired T-cell interferon-gamma (IFN-gamma) production, paclitaxel treatment did not alter IFN-gamma. We speculate that the immunostimulatory cytokine interleukin-12 (IL-12), which promoted T-cell activation and proliferation, was capable of reversing paclitaxel-mediated immunosuppression. Exogenous IL-12 fully reconstituted proliferative reactivity and enhanced IFN-gamma production by both normal host and TBH lymphocytes in vitro. Collectively, these data suggest that chemotherapeutic paclitaxel regimens impart significant but reversible inhibition of lymphocyte populations, and IL-12 may be a useful ancillary immunotherapeutic to overcome paclitaxel-induced modulation of lymphocyte activities. DA - 1998/1// PY - 1998/1// DO - 10.3109/08923979809031511 VL - 20 IS - 4 SP - 473-492 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031751801&partnerID=MN8TOARS ER - TY - CONF TI - Adaptive risk analysis for resource conservation programs AU - Meekhof, R. AU - Kuzma, J. AU - Mauriello, D. AU - Osborn, T. AU - Powell, M. AU - Rice, C. AU - Shafer, S. C2 - 1998/// C3 - Risk-Based Decision Making in Water Resources VIII DA - 1998/// SP - 172-186 ER - TY - JOUR TI - Sex-specific exons control DNA methyltransferase in mammalian germ cells AU - Mertineit, C. AU - Yoder, J.A. AU - Taketo, T. AU - Laird, D.W. AU - Trasler, J.M. AU - Bestor, T.H. T2 - Development DA - 1998/// PY - 1998/// VL - 125 IS - 5 SP - 889-897 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031889033&partnerID=MN8TOARS ER - TY - JOUR TI - A candidate mammalian DNA methyltransferase related to pmt1p of fission yeast AU - Yoder, J.A. AU - Bestor, T.H. T2 - Human Molecular Genetics AB - Trace levels of 5-methylcytosine persist in the DNA of mouse embryonic stem cells that are homozygous for null mutations in Dnmt1 , the gene for the one previously recognized metazoan DNA methyltransferase. This residual 5-methylcytosine may be the product of a candidate second DNA methyltransferase, Dnmt2, that has now been identified in human and mouse. Dnmt2 contains all the sequence motifs diagnostic of DNA (cytosine-5)-methyltransferases but appears to lack the large N-terminal regulatory domain common to other eukaryotic methyltransferases. Dnmt2 is more similar to a putative DNA methyltransferase of the fission yeast Schizosaccharomyces pombe than to Dnmt1. Dnmt2 produces multiple mRNA species that are present at low levels in all tissues of human and mouse and is not restricted to those cell types known to be active in de novo methylation. The human DNMT2 gene was mapped to chromosome 10p12-10p14 in a panel of radiation hybrids. Dnmt2 is a candidate for the activity that methylates newly integrated retroviral DNA and maintains trace levels of 5-methylcytosine in the DNA of embryonic stem cells homozygous for null mutations in Dnmt1. DA - 1998/2/1/ PY - 1998/2/1/ DO - 10.1093/hmg/7.2.279 VL - 7 IS - 2 SP - 279-284 SN - 1460-2083 UR - http://dx.doi.org/10.1093/hmg/7.2.279 ER - TY - CONF TI - Results from an eighteen year old Pinus brutia provenance-progeny trials AU - Isik, F. AU - Isik, K. C2 - 1998/// C3 - Forestry Symposium in 75th Anniversary of Turkish Republic DA - 1998/// VL - 75 ER - TY - CONF TI - Efforts on conservation of forest genetic resources in Turkey AU - Isik, F. C2 - 1998/// C3 - IUFRO All Division 2 Conference on Forest Genetics and Tree Improvement DA - 1998/// ER - TY - CONF TI - Differentiation of Pinus brutia populations revealed by principal component analysis AU - Isik, F. C2 - 1998/// C3 - The Proceedings of International Symposium on in-situ Conservation of Plant Genetic Diversity DA - 1998/// SP - 257-264 ER - TY - JOUR TI - The effect of prescribed fire on the regeneration of Lebanon Cedar (Cedrus libani A. Rich) in Kas, Antalya locality AU - Boydak, M. AU - Isik, F. AU - Dogan, B. T2 - Turkish Journal of Agriculture and Forestry DA - 1998/// PY - 1998/// VL - 22 SP - 399-404 ER - TY - RPRT TI - Genetic variation, heritability and genetic gains from Pinus brutia Ten. Provenance-progeny trials AU - Isik, F. A3 - Western Mediterranean Forest Research Institute DA - 1998/// PY - 1998/// M1 - 7 M3 - Technical Bulletin PB - Western Mediterranean Forest Research Institute SN - 7 ER - TY - JOUR TI - Genetic variation in Pinus brutia in Turkey: II. Branching and crown traits AU - Isik, K. AU - Isik, F. T2 - Silvae Genetica DA - 1998/// PY - 1998/// VL - 48 SP - 293-302 ER - TY - RPRT TI - The most common mistakes made in progeny test establishment AU - McKeand, S. E. A3 - Department of Forestry, N.C. State University DA - 1998/// PY - 1998/// PB - Department of Forestry, N.C. State University ER - TY - RPRT TI - Loblolly pine breeding values from 2nd-generation diallel progeny tests AU - Li, B. AU - Hatcher, A. V. AU - Sprauge, J. R. AU - McKeand, S. E. AU - Weir, R. J. A3 - N.C. State University-Industry Cooperative Tree Improvement Program C6 - 1 DA - 1998/// PY - 1998/// PB - N.C. State University-Industry Cooperative Tree Improvement Program ER - TY - RPRT TI - Grafting loblolly pine AU - McKeand, S. E. AU - Jett, J. B. A3 - Department of Forestry, N.C. State University DA - 1998/// PY - 1998/// PB - Department of Forestry, N.C. State University ER - TY - RPRT TI - Genetic basis for tree improvement AU - McKeand, S. E. A3 - Department of Forestry, N.C. State University DA - 1998/// PY - 1998/// PB - Department of Forestry, N.C. State University ER - TY - RPRT TI - Full-sib breeding values from 2nd-cycle diallel progeny tests AU - Li, B. AU - Hatcher, A. V. AU - Sprauge, J. R. AU - McKeand, S. E. AU - Weir, R. J. A3 - N.C. State University-Industry Cooperative Tree Improvement Program C6 - 2 DA - 1998/// PY - 1998/// PB - N.C. State University-Industry Cooperative Tree Improvement Program ER - TY - JOUR TI - Registration of NC96BGTD1, NC96BGTD2, and NC96BGTD3 wheat germplasm resistant to powdery mildew AU - Murphy, JP AU - Leath, S AU - Huynh, D AU - Navarro, RA AU - Shi, A T2 - CROP SCIENCE AB - Crop ScienceVolume 38, Issue 2 cropsci1998.0011183X003800020097x p. 570-571 Registration of Germplasm Registration of NC96BGTD1, NC96BGTD2, and NC96BGTD3 Wheat Germplasm Resistant to Powdery Mildew J. P. Murphy, Corresponding Author J. P. Murphy njpm@unity.ncsu.edu Dep. of Crop ScienceCorresponding author (njpm@unity.ncsu.edu).Search for more papers by this authorS. Leath, S. Leath Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD. Huynh, D. Huynh Dep. of Crop ScienceSearch for more papers by this authorR. A. Navarro, R. A. Navarro Dep. of Crop ScienceSearch for more papers by this authorA. Shi, A. Shi USDA-ARS and Dep. of Plant PathologySearch for more papers by this author J. P. Murphy, Corresponding Author J. P. Murphy njpm@unity.ncsu.edu Dep. of Crop ScienceCorresponding author (njpm@unity.ncsu.edu).Search for more papers by this authorS. Leath, S. Leath Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD. Huynh, D. Huynh Dep. of Crop ScienceSearch for more papers by this authorR. A. Navarro, R. A. Navarro Dep. of Crop ScienceSearch for more papers by this authorA. Shi, A. Shi USDA-ARS and Dep. of Plant PathologySearch for more papers by this author First published: 01 March 1998 https://doi.org/10.2135/cropsci1998.0011183X003800020097xCitations: 11AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume38, Issue2March–April 1998Pages 570-571 RelatedInformation DA - 1998/// PY - 1998/// DO - 10.2135/cropsci1998.0011183X003800020097x VL - 38 IS - 2 SP - 570-571 SN - 0011-183X ER - TY - JOUR TI - Reply to: Models for the in-host dynamics of malaria revisited: errors in some basic models lead to large overestimates of growth rates AU - Gravenor, MB AU - Lloyd, AL T2 - PARASITOLOGY AB - In the accompanying manuscript Saul (1998) points out that a model of within-host malaria population dynamics (Anderson, May & Gupta, 1989) can exhibit unrealistically large growth rates. He suggests that this error can be avoided by replacing the parameter r , which is the number of merozoites produced by each parasite at schizogony, with the value ln ( r )+1. This substitution does not, however, address the true underlying problem with the model, namely that whilst in reality there is small variation in the distribution of Plasmodium spp. life-spans, the use of the constant rate α assumes an exponential, and hence much more variable, distribution. This can allow the population to increase, over the time period of the average life-span (48 h in the case of Plasmodium falciparum ), by factors considerably larger than r . Saul identifies this assumption as unrealistic in terms of the biology of malaria, but it is not remedied in the proposed model. Within the structure of the original model there are two ways of addressing the growth rate problem. Firstly, the ‘growth constant’ r can be replaced by the value ln ( r )+1, so that if all parasites reinvade, the model increases by a factor r over 1 generation. As pointed out by Saul, this is an artificial device since it means that each parasite produces a reduced number of merozoites. Alternatively, a parasite can produce the observed number of merozoites, r , many of which do not reinvade. This is the situation in the original paper and Gravenor, McLean & Kwiatkowski (1995). In these papers the model does grow at a reasonable rate because the parameter β is estimated directly from observed growth rates. These points, however, are only an aside. Both the original and Saul's modified model can grow at the same rate and they both have the same distributional assumptions concerning parasite life-span. DA - 1998/11// PY - 1998/11// DO - 10.1017/S0031182098003229 VL - 117 IS - 5 SP - 409-410 SN - 1469-8161 ER - TY - JOUR TI - Two-gene interaction and linkage for bitterfree foliage in cucumber AU - Wehner, TC AU - Liu, JS AU - Staub, JE T2 - JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE AB - A second gene for bitterfree foliage in cucumber ( Cucumis sativus L.) was discovered. In a cross between two inbred lines having bitterfree foliage (NCG-093 and WI2757), the F 1 progeny were bitter, the F 2 progeny segregation frequency fit a ratio of 9 bitter : 7 bitterfree, and the BC 1 segregation frequencies fit a ratio of 1 bitter : 1 bitterfree. Thus, a second factor nonallelic to the previous bitterfree gene, bi , controls the bitterfree trait. When F 2 and BC 1 progeny resulting from crosses of bitterfree NCG-093 with other bitter lines were studied, the second factor for bitterfree in NCG-093 fit a recessive, single-gene model. The existence of a second, recessive bitterfree gene was confirmed in additional crosses, and the gene was designated bi-2. Further analysis of two crosses indicated that bi-2 was linked with the short petiole ( sp ) gene (map distance = 11 cM). DA - 1998/5// PY - 1998/5// DO - 10.21273/jashs.123.3.401 VL - 123 IS - 3 SP - 401-403 SN - 2327-9788 KW - Cucumis sativus KW - vegetable breeding KW - qualitative genetics KW - fruit quality ER - TY - JOUR TI - The eastern Asian and eastern and western North American floristic disjunction: Congruent phylogenetic patterns in seven diverse genera AU - Xiang, QY AU - Soltis, DE AU - Soltis, PS T2 - MOLECULAR PHYLOGENETICS AND EVOLUTION AB - One of the most remarkable examples of intercontinental disjunction of the North Temperate Flora involves eastern Asia and eastern and western North America. Although there has been considerable interest in this phytogeographic pattern for over 150 years (e.g., Gray, 1859; Li, 1952; Graham, 1972; Boufford and Spongberg, 1983; Wu, 1983; Tiffney, 1985a, 1985b), relationships among taxa displaying the disjunction remain obscure. Understanding phylogenetic relationships is, however, a prerequisite for historical biogeographic analyses of this distributional pattern. To understand better the relationships of taxa displaying this intercontinental disjunction, phylogenetic analyses were conducted using a variety of DNA data sets for species of four genera (Cornus, Boykinia, Tiarella, and Trautvetteria) that occur in eastern Asia, eastern North America, and western North America. An area cladogram was constructed for each of the four genera, all of which show a similar pattern of relationship: the eastern Asian species are sister to all North American species. An identical phylogenetic pattern is also found in three other taxa exhibiting this disjunction (Aralia sect. Aralia, Calycanthus, and Adiantum pedatum). The congruent phylogenetic pattern found in these seven diverse genera raises the possibility of a common origin of the eastern Asia, eastern and western North America disjunction. The data are in agreement with the long-standing hypothesis that this well-known floristic disjunction represents the fragmentation of a once continuous Mixed Mesophytic forest community and suggest that the disjunction may have involved only two major vicariance events: an initial split between Eurasia and North America, followed by the isolation of floras between eastern and western North America. However, congruence between phylogenies and geographic distributions does not necessarily indicate an identical phytogeographic history. Taxa exhibiting the same phylogenetic pattern may have originated at different geological times. Analysis of divergence times using the molecular clock indicates that species of Cornus, Boykinia, and Calycanthus may have diverged at different geological times, suggesting that the floristic disjunction involving eastern Asia and North America may not be simple; it may have involved multiple historical events at very different geological times in different genera. DA - 1998/10// PY - 1998/10// DO - 10.1006/mpev.1998.0524 VL - 10 IS - 2 SP - 178-190 SN - 1095-9513 ER - TY - JOUR TI - Phylogenetic relationships of cornaceae and close relatives inferred from matK and rbcL sequences AU - Xiang, QY AU - Soltis, DE AU - Soltis, PS T2 - AMERICAN JOURNAL OF BOTANY AB - Phylogenetic relationships were inferred using nucleotide sequences of the chloroplast gene matK for members of Cornales, a well‐supported monophyletic group comprising Cornaceae and close relatives. The shortest trees resulting from this analysis were highly concordant with those based on previous phylogenetic analysis of rbcL sequences. Analysis of a combined matK and rbcL sequence data set (a total of 2652 bp [base pairs]) provided greater resolution of relationships and higher internal support for clades compared to the individual data sets. Four major clades (most inclusive monophyletic groups) of Cornales are indicated by both sets of genes: (1) Cornus‐Alangium, (2) nyssoids ( Nyssa‐Davidia‐Camptotheca )‐mastixioids ( Mastixia, Diplopanax ), (3) Curtisia, and (4) Hydrangeaceae‐Loasaceae. The combined evidence indicates that clades 2 and 3 are sisters, with clade 4 sister to the remainder of Cornales. These relationships are also supported by other lines of evidence, including synapomorphies in fruit and pollen morphology and gynoecial vasculature. Comparisons of matK and rbcL sequences based on one of the most parsimonious rbcL‐matK trees indicate that matK has a much higher A‐T content (66.9% in matK vs. 55.8% in rbcL ) and a lower transition:transversion ratio (1.23 in matK vs. 2.21 in rbcL ). The total number of nucleotide substitutions per site for matK is 2.1 times that of rbcL in Cornales. These findings are similar to recent comparisons of matK and rbcL in other dicots. Variable sites of matK are almost evenly distributed among the three codon positions (1.0:1.0:1.3), whereas variable sites of rbcL are mostly at the third position (1.8:1.0:7.5). Among‐lineages rates of nucleotide substitutions in rbcL are basically homogeneous throughout Cornales, but are more heterogeneous in matK . DA - 1998/2// PY - 1998/2// DO - 10.2307/2446317 VL - 85 IS - 2 SP - 285-297 SN - 1537-2197 KW - Cornales KW - matK KW - molecular evolution KW - molecular phylogeny KW - rbcL ER - TY - JOUR TI - Origin and biogeography of Aesculus L. (Hippocastanaceae): a molecular phylogenetic perspective AU - Xiang, Qiu-Yun AU - Crawford, D. J. AU - Wolfe, A. D. AU - Tang, Y.-C. AU - DePamphilis, C. W. T2 - Evolution AB - Sequences of chloroplast gene matK and internal transcribed spacers of nuclear ribosomal RNA genes were used for phylogenetic analyses of Aesculus, a genus currently distributed in eastern Asia, eastern and western North America, and southeastern Europe. Phylogenetic relationships inferred from these molecular data are highly correlated with the geographic distributions of species. The identified lineages closely correspond to the five sections previously recognized on the basis of morphology. Ancestral character-state reconstruction, a molecular clock, and fossil evidence were used to infer the origin and biogeographic history of the genus within a phylogenetic framework. Based on the molecular phylogenetic reconstruction of the genus, sequence divergence, and paleontological evidence, we infer that the genus originated during the transition from the Cretaceous to the Tertiary (~65 M.Y.B.P.) at a high latitude in eastern Asia and spread into North America and Europe as an element of the "boreotropical flora"; the current disjunct distribution of the genus resulted from geological and climatic changes during the Tertiary. DA - 1998/// PY - 1998/// DO - 10.1111/j.1558-5646.1998.tb01828.x VL - 52 IS - 1998 SP - 988–997 ER - TY - JOUR TI - Assessing hybridization in natural populations of Penstemon (Scrophulariaceae) using hypervariable intersimple sequence repeat (ISSR) bands AU - Wolfe, AD AU - Xiang, QY AU - Kephart, , SR T2 - MOLECULAR ECOLOGY AB - Inferences regarding hybridization rely on genetic markers to differentiate parental taxa from one another. Intersimple sequence repeat (ISSR) markers are based on single‐primer PCR reactions where the primer sequence is derived from di‐ and trinucleotide repeats. These markers have successfully been used to assay genetic variability among cultivated plants, but have not yet been tested in natural populations. We used genetic markers generated from eight ISSR primers to examine patterns of hybridization and purported examples of hybrid speciation in Penstemon (Scrophulariaceae) in a hybrid complex involving P. centranthifolius , P. grinnellii , P. spectabilis and P. clevelandii . This hybrid complex has previously been studied using three molecular data sets (allozymes, and restriction‐site variation of nuclear rDNA and chloroplast DNA). These studies revealed patterns of introgression involving P. centranthifolius , but were unsuccessful in determining whether gene flow occurs among the other species, and support for hypotheses of diploid hybrid speciation was also lacking. In this study, we were able to fingerprint each DNA accession sampled with one to three ISSR primers and most accessions could be identified with a single primer. We found population‐ and species‐specific markers for each taxon surveyed. Our results: (i) do not support the hybrid origin of P. spectabilis ; (ii) do support the hypothesis that P. clevelandii is a diploid hybrid species derived from P. centranthifolius and P. spectabilis ; and (iii) demonstrate that pollen‐mediated gene flow via hummingbird vectors is prevalent in the hybrid complex. DA - 1998/9// PY - 1998/9// DO - 10.1046/j.1365-294x.1998.00425.x VL - 7 IS - 9 SP - 1107-1125 SN - 1365-294X KW - diploid hybrid speciation KW - genetic marker KW - introgression KW - ISSR KW - Penstemon KW - pollen-mediated gene flow ER - TY - JOUR TI - Pharmacokinetics of gentamicin in healthy adult horses during intravenous fluid administration AU - Jones, SL AU - Wilson, WD AU - Milhalyi, JE T2 - JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS AB - Journal of Veterinary Pharmacology and TherapeuticsVolume 21, Issue 3 p. 247-249 Pharmacokinetics of gentamicin in healthy adult horses during intravenous fluid administration S.L. Jones, S.L. Jones Present address: Division of Infectious Diseases, Washington University School of Medicine, Box 8051, 660 S. Euclid Ave, St Louis, MO 66110,Search for more papers by this authorW.D. Wilson, W.D. Wilson CorrespondenceSearch for more papers by this authorJ.E. Milhalyi, J.E. Milhalyi Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616,Search for more papers by this author S.L. Jones, S.L. Jones Present address: Division of Infectious Diseases, Washington University School of Medicine, Box 8051, 660 S. Euclid Ave, St Louis, MO 66110,Search for more papers by this authorW.D. Wilson, W.D. Wilson CorrespondenceSearch for more papers by this authorJ.E. Milhalyi, J.E. Milhalyi Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616,Search for more papers by this author First published: 05 January 2002 https://doi.org/10.1046/j.1365-2885.1998.00123.xCitations: 10Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume21, Issue3June 1998Pages 247-249 RelatedInformation DA - 1998/6// PY - 1998/6// DO - 10.1046/j.1365-2885.1998.00123.x VL - 21 IS - 3 SP - 247-249 SN - 0140-7783 UR - http://europepmc.org/abstract/med/9673967 ER - TY - JOUR TI - NMR applications in cell wall research AU - Ralph, J. AU - Hatfield, R. AU - Fanchuang, L. AU - Marita, J. M. AU - Ede, R. M. AU - Junpeng, S. R. AU - Quideau, S. AU - Helm, R. AU - Grabber, J. AU - Kim, H. AU - Jimenez-Monteon, G. AU - Zhang, Y. AU - Landucci, L. AU - Sederoff, R. AU - Boudet, A. T2 - TAPPI Journal DA - 1998/// PY - 1998/// IS - 1998 ER - TY - JOUR TI - Electrolyte disturbances in foals with severe rhabdomyolysis AU - Perkins, G AU - Valberg, SJ AU - Madigan, JM AU - Carlson, GP AU - Jones, SL T2 - JOURNAL OF VETERINARY INTERNAL MEDICINE AB - Marked electrolyte abnormalities characterized by profound hyperkalemia, hyponatremia, hypocalcemia, and hyperphosphatemia were noted in 4 neonatal foals with acute rhabdomyolysis and pigmenturia. In 2 foals, rhabdomyolysis developed 4-6 days after admission for dysmaturity, and in 2 foals, rhabdomyolysis was evident on presentation. Rhabdomyolysis was a consequence of selenium deficiency with or without vitamin E deficiency, possibly combined with increased oxidant stress due to sepsis or hypoxia and reperfusion injury after parturition. Foals gained from 7 to 15% of their initial body weight within 48 hours of developing rhabdomyolysis. Three of the foals developed cardiac arrhythmias characterized by spiked T waves and decreased-amplitude P waves. Postmortem examination of 2 foals revealed extensive myodegeneration and renal tubular nephrosis; renal cortical necrosis with myocardial necrosis was noted in 1 foal. Destruction of the major intracellular compartment (intracellular fluid [ICF]) through extensive myonecrosis combined, in some cases, with myoglobinuric renal insufficiency produced major fluid shifts and life-threatening electrolyte derangements. With the major ICF compartment disrupted, hyperkalemia was most effectively treated using mineralocorticoids, loop diuretics, and ion exchange resins to enhance elimination. In addition, i.v. calcium, glucose, insulin, and sodium bicarbonate were administered, which helped redistribute potassium to the ICF. Severe rhabdomyolysis should be included in the differential diagnoses of hyperkalemia, hyponatremia, hypocalcemia, and hyperphosphatemia in neonatal foals. DA - 1998/// PY - 1998/// DO - 10.1111/j.1939-1676.1998.tb02114.x VL - 12 IS - 3 SP - 173-177 SN - 0891-6640 KW - horses KW - hyperkalemia KW - muscle KW - myopathy KW - selenium ER - TY - CHAP TI - Disorders of the large intestine AU - Jones, S. L. AU - Spear, S. AU - Snyder, J. R. T2 - Equine internal medicine A2 - W. Bailey, S. Reed CN - SF951 .E565 1998 PY - 1998/// SP - 636-694 PB - Philadelphia, PA: W.B. Saunders ER - TY - JOUR TI - A role for the actin-bundling protein L-plastin in the regulation of leukocyte integrin function AU - Jones, SL AU - Wang, J AU - Turck, CW AU - Brown, EJ T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - Regulation of leukocyte integrin avidity is a crucial aspect of inflammation and immunity. The actin cytoskeleton has an important role in the regulation of integrin function, but the cytoskeletal proteins involved are largely unknown. Because inflammatory stimuli that activate integrin-mediated adhesion in human polymorphonuclear neutrophils (PMN) and monocytes cause phosphorylation of the actin-bundling protein l -plastin, we tested whether l -plastin phosphorylation was involved in integrin activation. l -plastin-derived peptides that included the phosphorylation site (Ser-5) rapidly induced leukocyte integrin-mediated adhesion when introduced into the cytosol of freshly isolated primary human PMN and monocytes. Substitution of Ala for Ser-5 abolished the ability of the peptide to induce adhesion. Peptide-induced adhesion was sensitive to pharmacologic inhibition of phosphoinositol 3-kinase and protein kinase C, but adhesion induced by a peptide containing a phosphoserine at position 5 was insensitive to inhibition. These data establish a novel role for l -plastin in the regulation of leukocyte adhesion and suggest that many signaling events implicated in integrin regulation act via induction of l -plastin phosphorylation. DA - 1998/8/4/ PY - 1998/8/4/ DO - 10.1073/pnas.95.16.9331 VL - 95 IS - 16 SP - 9331-9336 SN - 0027-8424 UR - http://europepmc.org/abstract/med/9689080 ER - TY - CHAP TI - Bioengineering resistance to plant-parasitic nematodes AU - Opperman, C.H. AU - Conkling, M.A. T2 - Plant and nematode interactions / co-eds Kenneth R. Barker, Gary A. Pederson, Gary L. Windham. Madison, Wis.: American Society of Agronomy, Inc.: Crop Science Society of America, Inc.: Soil Science Society of America, Inc., 1998. CN - SB998.N4 P53 1998 PY - 1998/// SP - 239-250 PB - Madison, Wis.: American Society of Agronomy, Inc.: Crop Science Society of America, Inc.: Soil Science Society of America, Inc. ER - TY - JOUR TI - Propagation of Thuja x 'Green Giant' by stem cuttings: effects of growth stage, type of cutting, and IBA treatment AU - Griffin, J. J. AU - Blazich, F. A. AU - Ranney, T. G. T2 - Journal of Environmental Horticulture DA - 1998/// PY - 1998/// VL - 16 IS - 4 SP - 212-214 ER - TY - CHAP TI - The dependence of Fed-1 light regulation on translation AU - Petracek, M. E. AU - Dickey, L. F. AU - Hansen, E. R. AU - Sowinski, D. A. AU - Nguyen, T. AU - Allen, G. C. AU - Thompson, G. F. T2 - A look beyond transcription: Mechanisms determining mRNAstability and translation in plants A2 - J. Bailey-Serres, A2 - Gallie, D. R. CN - QK981.4 .L66 1998 PY - 1998/// SP - 96-101 PB - Washington, DC: American Society of Plant Physiologists ER - TY - CONF TI - Effects of low salinity on growth and survival of Southern flounder (Paralichthys lethostigma) larvae and juveniles AU - Daniels, H.V. AU - Borski, R.J. C2 - 1998/// C3 - Nutrition and technical development of aquaculture: Proceedings of the twenty-seventh U.S.-Japan Aquaculture Symposium, Durham, New Hampshire, U.S.A., Nov. 1998 DA - 1998/// SP - 187-192 M1 - 1998 Nov. ER - TY - JOUR TI - Bollworm (Helicoverpa zea): adaptation to BT toxin? AU - Lambert, A. L. AU - Bradley, J. R., Jr. AU - Gould, F. AU - Van Duyn, J. W. T2 - Beltwide Cotton Conferences. Proceedings DA - 1998/// PY - 1998/// VL - 2 IS - 1998 SP - 1033-1037 ER - TY - JOUR TI - Testing hollies for tolerance to flooding and high temperatures AU - Ranney, T. G. T2 - American Nurseryman DA - 1998/// PY - 1998/// VL - 187 IS - 4 SP - 50-51 ER - TY - JOUR TI - Propagation of Magnolia virginiana 'Santa Rosa' by semihardwood cuttings AU - Griffin, J. J. AU - Blazich, F. A. AU - Ranney, T. G. T2 - Proceedings of Southern Nurserymen's Association Research Conference Annual Report DA - 1998/// PY - 1998/// VL - 43 IS - 1998 SP - 340-343 ER - TY - JOUR TI - Natural resistance of Malus to adult Japanese beetles AU - Fulcher, A. F. AU - Ranney, T. G. AU - Burton, J. D. AU - Walgenbach, J. F. AU - Danehower, D. A. T2 - American Nurseryman DA - 1998/// PY - 1998/// VL - 188 IS - 10 SP - 56-57 ER - TY - JOUR TI - Improving European beech adaptability for the Southeastern United States with stress-tolerant rootstocks AU - Cote, K. D. AU - Warren, S. L. AU - Ranney, T. G. T2 - Proceedings of Southern Nurserymen's Association Research Conference Annual Report DA - 1998/// PY - 1998/// VL - 43 IS - 1998 SP - 337-339 ER - TY - JOUR TI - Heat tolerance in perennial salvias AU - Lasseigne, F. T. AU - Warren, S. L. AU - Blazich, F. A. AU - Ranney, T. G. T2 - Proceedings of Southern Nurserymen's Association Research Conference Annual Report DA - 1998/// PY - 1998/// VL - 43 IS - 1998 SP - 442-445 ER - TY - JOUR TI - Evaluation of Photinia spp. For resistance to entomosporium leaf spot, 1996, 1997 AU - Benson, D. M. AU - Ranney, T. G. AU - Parker, K. C. T2 - Biological and Cultural Tests for Control of Plant Diseases DA - 1998/// PY - 1998/// VL - 13 IS - 1998 SP - 68 ER - TY - JOUR TI - Biorational plant protectants for controlling adult Japanese beetles AU - Witt, J. D. AU - Ranney, T. G. AU - Warren, S. L. AU - Baker, J. R. T2 - Proceedings of Southern Nurserymen's Association Research Conference Annual Report DA - 1998/// PY - 1998/// VL - 43 IS - 1998 SP - 175-178 ER - TY - JOUR TI - Analytical study of fluid flow and heat transfer during forced convection in a composite channel partly filled with a Brinkman-Forchheimer porous medium AU - Kuznetsov, AV T2 - FLOW TURBULENCE AND COMBUSTION DA - 1998/// PY - 1998/// DO - 10.1023/A:1009998703180 VL - 60 IS - 2 SP - 173-192 SN - 1386-6184 KW - porous medium KW - forced convection KW - Brinkman-Forchheimer-extended Darcy equation KW - interface region ER - TY - CHAP TI - Inositol lipid signaling: what can we learn from plants? AU - Heilmann, I. AU - Perera, I. Y. AU - Stevenson, J. M. AU - Ransom, W. D. AU - Gross, W. AU - Boss, W. F. T2 - Advances in lipids research A2 - J. Sanchez, E. Cerda-Olmedo A2 - Martinez-Force, E. PY - 1998/// SP - 394-397 PB - Sevilla, Spain: University of Sevilla Press ER - TY - JOUR TI - Homomultimeric protease in the hyperthermophilic bacterium Thermotoga maritima has structural and amino acid sequence homology to bacteriocins in mesophilic bacteria AU - Hicks, PM AU - Rinker, KD AU - Baker, , JR AU - Kelly, RM T2 - FEBS LETTERS AB - A novel homomultimeric protease (> 669 kDa), based on 31 kDa subunits, was purified from cell extracts of the hyperthermophilic bacterium Thermotoga maritima. This protease exhibits activity toward chymotrypsin and trypsin substrates, optimally at 90 degrees C and pH 7.1, and has a half-life of 36 min at 95 degrees C. Transmission electron microscopy established that the protease consists of a large globular assembly which appears circular from the front view. The function of this protease in T. maritima remains unclear, although putative homologs include a 29 kDa antigen from Mycobacterium tuberculosis and a 31 kDa monomer of a high molecular weight bacteriocin produced by Brevibacterium linens [Valdes-Stauber, N. and Scherer, S. (1996) Appl. Environ. Microbiol. 62, 1283-1286]. The relationship of these mesophilic proteins to the T. maritima protease suggests that their antibacterial activity may involve elements of proteolysis, and raises the prospect for antimicrobial ecological strategies in hyperthermophilic niches. DA - 1998/12/4/ PY - 1998/12/4/ DO - 10.1016/S0014-5793(98)01451-3 VL - 440 IS - 3 SP - 393-398 SN - 0014-5793 KW - proteolysis KW - bacteriocin KW - Thermotoga ER - TY - JOUR TI - Estimating the rate of evolution of the rate of molecular evolution AU - Thorne, JL AU - Kishino, H AU - Painter, IS T2 - MOLECULAR BIOLOGY AND EVOLUTION AB - A simple model for the evolution of the rate of molecular evolution is presented. With a Bayesian approach, this model can serve as the basis for estimating dates of important evolutionary events even in the absence of the assumption of constant rates among evolutionary lineages. The method can be used in conjunction with any of the widely used models for nucleotide substitution or amino acid replacement. It is illustrated by analyzing a data set of rbcL protein sequences. DA - 1998/12// PY - 1998/12// DO - 10.1093/oxfordjournals.molbev.a025892 VL - 15 IS - 12 SP - 1647-1657 SN - 0737-4038 KW - molecular clock KW - phylogeny KW - Markov chain Monte Carlo KW - Metropolis-Hastings algorithm ER - TY - JOUR TI - Caenorhabditis elegans: A genetic guide to parasitic nematode biology AU - Bird, D.Mck. AU - Opperman, C.H. T2 - Journal of Nematology DA - 1998/// PY - 1998/// VL - 30 IS - 3 SP - 299-308 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0032357095&partnerID=MN8TOARS ER - TY - JOUR TI - A strategy for the third breeding cycle of loblolly pine in the Southeastern US AU - McKeand, S. E. AU - Bridgwater, F. E. T2 - Silvae Genetica DA - 1998/// PY - 1998/// VL - 47 IS - 4 SP - 223-234 ER - TY - JOUR TI - A spatially explicit stochastic model demonstrates the feasibility of Wright's Shifting Balance Theory AU - Peck, SL AU - Ellner, SP AU - Gould, F T2 - EVOLUTION DA - 1998/12// PY - 1998/12// DO - 10.2307/2411353 VL - 52 IS - 6 SP - 1834-1839 SN - 1558-5646 KW - diffusion approximation KW - Sewall Wright KW - shifting-balance theory KW - stochastic simulation models KW - substructured populations ER - TY - JOUR TI - The importance of archival and herbarium materials in understanding the role of oospores in late blight epidemics of the past AU - Ristaino, JB T2 - PHYTOPATHOLOGY AB - Nineteenth and early twentieth century botanists and mycologists collected healthy and infected plant materials from many regions of the world. Some of these plant collections preserved in herbaria around the world contain samples that are of considerable significance to epidemiologists, population biologists, and botanists. The advent of the polymerase chain reaction (PCR) and the development of molecular marker technology has made DNA amplification from herbarium material a reality. In this mini-review, archival letters and herbarium samples are used to track the historical role of oospores in the biology of the potato late blight pathogen. DNA was successfully amplified by PCR with the Phytophthora infestans-specific PCR primer, PINF, and the universal primer, ITS 5, from oospores observed in a field sample of potato collected by G. P. Clinton in 1902. This experiment demonstrates the potential to utilize molecular methods to amplify DNA from historical samples of the late blight pathogen and represents the earliest definitive record of oospores of the pathogen in field samples in the United States. Studies based upon such materials and techniques, although high risk and laborious, have the potential to open a new window to epidemics of the past. DA - 1998/11// PY - 1998/11// DO - 10.1094/PHYTO.1998.88.11.1120 VL - 88 IS - 11 SP - 1120-1130 SN - 1943-7684 KW - oomycetes ER - TY - JOUR TI - Seroprevalence of Toxoplasma gondii and Trichinella spiralis in North Carolina black bears (Ursus americanus) AU - Nutter, FB AU - Levine, JF AU - Stoskopf, MK AU - Gamble, HR AU - Dubey, JP T2 - JOURNAL OF PARASITOLOGY DA - 1998/10// PY - 1998/10// DO - 10.2307/3284644 VL - 84 IS - 5 SP - 1048-1050 SN - 0022-3395 ER - TY - JOUR TI - QTL mapping of foliar glycoalkaloid aglycones in Solanum tuberosum x S-berthaultii potato progenies: quantitative variation and plant secondary metabolism AU - Yencho, GC AU - Kowalski, SP AU - Kobayashi, RS AU - Sinden, SL AU - Bonierbale, MW AU - Deahl, KL T2 - THEORETICAL AND APPLIED GENETICS DA - 1998/9// PY - 1998/9// DO - 10.1007/s001220050932 VL - 97 IS - 4 SP - 563-574 SN - 0040-5752 KW - solasodine KW - solanidine KW - steroid alkaloid KW - restriction fragment length polymorphisms (RFLPs) KW - plant breeding ER - TY - JOUR TI - PASSML: combining evolutionary inference and protein secondary structure prediction AU - Lio, P AU - Goldman, N AU - Thorne, JL AU - Jones, DT T2 - BIOINFORMATICS AB - Evolutionary models of amino acid sequences can be adapted to incorporate structure information; protein structure biologists can use phylogenetic relationships among species to improve prediction accuracy. Results : A computer program called PASSML ('Phylogeny and Secondary Structure using Maximum Likelihood') has been developed to implement an evolutionary model that combines protein secondary structure and amino acid replacement. The model is related to that of Dayhoff and co-workers, but we distinguish eight categories of structural environment: alpha helix, beta sheet, turn and coil, each further classified according to solvent accessibility, i.e. buried or exposed. The model of sequence evolution for each of the eight categories is a Markov process with discrete states in continuous time, and the organization of structure along protein sequences is described by a hidden Markov model. This paper describes the PASSML software and illustrates how it allows both the reconstruction of phylogenies and prediction of secondary structure from aligned amino acid sequences.PASSML 'ANSI C' source code and the example data sets described here are available at http://ng-dec1.gen.cam.ac.uk/hmm/Passml.html and 'downstream' Web pages.P.Lio@gen.cam.ac.uk DA - 1998/// PY - 1998/// DO - 10.1093/bioinformatics/14.8.726 VL - 14 IS - 8 SP - 726-733 SN - 1367-4803 ER - TY - JOUR TI - Independence of the Mj nematode resistance gene from 17 gene loci in cucumber AU - Walters, S. A. AU - Wehner, T. C. T2 - HortScience DA - 1998/// PY - 1998/// VL - 33 IS - 6 SP - 1050-1052 ER - TY - JOUR TI - Feeding disruption bioassay for species and Bacillus thuringiensis resistance diagnosis for Heliothis virescens and Helicoverpa zea in cotton (Lepidoptera : Noctuidae) AU - Bailey, WD AU - Zhao, G AU - Carter, LM AU - Gould, F AU - Kennedy, GG AU - Roe, RM T2 - CROP PROTECTION AB - Bioassay methodology was developed for species diagnosis of Heliothis virescens compared with Helicoverpa zea in cotton and to detect H. virescens larvae with significant levels of resistance to the biopesticide, Bacillus thuringiensis. The assay end-point is feeding disruption, which is measured by a lack of fecal production by larvae exposed to a diagnostic dose of CrylAc in a blue indicator diet. In laboratory tests, the bioassay accurately distinguished neonates of H. zea from H. virescens and was able to detect B. thuringiensis resistance in H. virescens. The assay is rapid compared with mortality assays and should be inexpensive. The assay should also be adaptable to current cotton integrated pest management programs and sampling techniques and detect most physiological mechanisms of B. thuringiensis resistance. The potential utility of the feeding disruption assay in cotton integrated pest management and with other crops, insect pests and insecticides is discussed. The studies reported here were conducted on laboratory strains of B. thuringiensis susceptible H. virescens and H. zea and a highly B. thuringiensis-resistant laboratory strain of H. virescens (YHD2) originally collected in North Carolina. DA - 1998/9// PY - 1998/9// DO - 10.1016/S0261-2194(98)00057-X VL - 17 IS - 7 SP - 591-598 SN - 1873-6904 KW - tobacco budworm KW - Heliothis virescens KW - bollworm KW - Helicoverpa zea KW - Bacillus thuringiensis KW - cotton KW - resistance ER - TY - JOUR TI - Anatomic site and interanimal variability in morphologic characteristics of bottlenose dolphin (Tursiops truncatus) skin likely to affect dermal absorption studies AU - Colbert, A. A. AU - Stoskopf, M. AU - Brownie, C. AU - Scott, G. I. AU - Levine, J. T2 - American Journal of Veterinary Research DA - 1998/// PY - 1998/// VL - 59 IS - 11 SP - 1398-1403 ER - TY - JOUR TI - An experimental chain of infection reveals that distinct Borrelia burgdorferi populations are selected in arthropod and mammalian hosts AU - Ryan, , JR AU - Levine, JF AU - Apperson, CS AU - Lubke, L AU - Wirtz, RA AU - Spears, PA AU - Orndorff, PE T2 - MOLECULAR MICROBIOLOGY AB - The prokaryotic, spirochaetal microorganism Borrelia burgdorferi is the causative agent of Lyme disease, an arthropod‐borne disease of a variety of vertebrates and the most prevalent arthropod‐borne disease of humans in the United States. In order to understand better the normal life cycle of B. burgdorferi , an experimental chain of infection was devised that involved multiple sequential arthropod and mammalian passages. By examining populations of B. burgdorferi emerging from different points in this infectious chain, we demonstrate that selection of B. burgdorferi populations peculiar to arthropod or vertebrate hosts is a property of at least one of the two ecologically distinct strains we examined. Distinct B. burgdorferi populations were identified using an antigenic profile, defined by a set of monoclonal antibodies to eight B. burgdorferi antigens, and a plasmid profile, defined by the naturally occurring plasmids in the starting clonal populations. These two profiles constituted the phenotypical signature of the population. In the strain exhibiting selection in the different hosts, transition from one host to another produced a striking series of alternating phenotypical signatures down the chain of infection. At the molecular level, the alternating signatures were manifested as a reciprocal relationship between the expression of certain antigenic forms of outer surface protein (Osp) B and OspC. In the case of OspC, the antigenic changes could be correlated to the presence of one of two distinctly different alleles of the ospC gene in a full‐length and presumably transcriptionally active state. In the case of OspB, two alleles were again identified. However, their differences were minor and their relationship to OspB antigenic variation more complicated. In addition to the reciprocating changes in the antigenic profile, a reciprocating change in the size (probably the multimeric state) of a 9.0 kbp supercoiled plasmid was also noted. Selection of distinct populations in the tick may be responsible for the microorganism's ability to infect a wide range of vertebrate hosts efficiently, in that the tick might provide selective pressure for the elimination of the population selected in the previous host. DA - 1998/10// PY - 1998/10// DO - 10.1046/j.1365-2958.1998.01071.x VL - 30 IS - 2 SP - 365-379 SN - 1365-2958 ER - TY - JOUR TI - The family 1 beta-glucosidases from Pyrococcus furiosus and Agrobacterium faecalis share a common catalytic mechanism AU - Bauer, MW AU - Kelly, RM T2 - BIOCHEMISTRY AB - Comparisons of catalytic mechanisms have not previously been performed for homologous enzymes from hyperthermophilic and mesophilic sources. Here, the beta-glucosidase from the hyperthermophilic archaeon Pyrococcus furiosus was recombinantly produced in Escherichia coli and shown to have biophyscial and biochemical properties identical to those of the wild-type enzyme. Moreover, the recombinant enzyme was subjected to a detailed kinetic investigation at 95 degreesC to compare its catalytic mechanism to that determined at 37 degreesC for the beta-glucosidase (abg) from the mesophilic bacterium, Agrobacterium faecalis [Kempton, J., and Withers, S. G. (1992) Biochemistry 31, 9961]. These enzymes have amino acid sequences that are 33% identical and have been classified as family 1 glycosyl hydrolases on the basis of amino acid sequence similarities. Both enzymes have similar broad specificities for both sugar and aglycone moieties and exhibit nearly identical pH dependences for their kinetic parameters with several different substrates. Bronsted plots were constructed for bgl at several temperatures using a series of aryl glucoside substrates. These plots were concave downward at all temperatures, indicating that bgl utilized a two-step mechanism similar to that of abg and that the rate-limiting step in this mechanism did not change with temperature for any given aryl glucoside. The Bronsted coefficient for bgl at 95 degreesC (beta1g = -0.7) was identical to that for abg at 37 degreesC and implies that these enzymes utilize nearly identical transition states, at least in regard to charge accumulation on the departing glycosidic oxygen. In addition, a high correlation coefficient (rho = 0.97) for the linear free energy relationship between these two enzymes and similar inhibition constants for these two enzymes with several ground state and transition state analogue inhibitors further indicate that these enzymes stabilize similar transition states. The mechanistic similarities between these two enzymes are noteworthy in light of the large difference in their temperature optima. This suggests that, in the presumed evolution that occurred between the hyperthermophilic archaeal enzyme and the mesophilic bacterial enzyme, structural modifications must have been selected which maintained the integrity of the active site structure and, therefore, the specificity of transition state interactions, while adapting the overall protein structure to permit function at the appropriate temperature. DA - 1998/12/8/ PY - 1998/12/8/ DO - 10.1021/bi9814944 VL - 37 IS - 49 SP - 17170-17178 SN - 0006-2960 ER - TY - JOUR TI - Optimum planting density and harvest stage for little-leaf and normal-leaf cucumbers for once-over harvest AU - Schultheis, , JR AU - Wehner, TC AU - Walters, SA T2 - CANADIAN JOURNAL OF PLANT SCIENCE AB - Optimum planting density and harvest stage were determined for once-over harvest of little-leaf and normal-leaf cucumbers. Three harvest stages (10, 25, and 50% oversize fruit) and four plant densities (37,000, 75,000, 150,000, and 300,000 plants/ha) were evaluated on little-leaf cucumber (H-19) and normal-leaf cucumber (Sumter and Regal). Plant density did not affect skin color, seedcell size, and seed size in the cultivars evaluated. However, lighter skin color, larger seedcell, and larger seed size were detected at the later harvest stages in H-19. Harvest stage did not influence fruit skin color in Regal and Sumter, but seedcell size and seed size increased quadratically with harvest stage. H-19 produced the highest yield (tonne/ha) and dollar value ($/ha) followed by Regal and Sumter. Considering fruit quality and dollar value, the 10% harvest stage at 330 000 plants ha −1 was the optimum stage and density for once-over harvest of H-19 under North Carolina growing conditions. Higher yield occurred at the later harvest stages, but poorer fruit quality (increased seed and seedcell size, and a lighter skin color) was associated with those stages. Fruit quality and dollar value of Regal was best at the 10% harvest stage at approximately 240 000 plants ha −1 , while 200 000 plants ha −1 was best for Sumter. Key words: Cucumis sativus, cucumber, plant type, spacing, crop ideotype, vegetable production DA - 1998/4// PY - 1998/4// DO - 10.4141/P97-065 VL - 78 IS - 2 SP - 333-340 SN - 0008-4220 KW - Cucumis sativus KW - cucumber KW - plant type KW - spacing KW - crop ideotype KW - vegetable production ER - TY - JOUR TI - Monitoring pyrethroid resistance in bollworm (Lepidoptera : Noctuidae) moths in Missouri, 1988 to 1994 AU - Sorenson, CE AU - Schreiber, A AU - Townsend, HG AU - Abd-Elghafar, SF AU - Fairchild, ML AU - Knowles, CO T2 - JOURNAL OF ENTOMOLOGICAL SCIENCE AB - From 1988 to 1994, adult vial bioassays were conducted on bollworms, Helicoverpa zea (Boddie), collected from pheromone traps in Missouri to determine their susceptibility to pyrethroids. Although most moths were susceptible to cypermethrin, many assays contained individuals that survived concentrations of 5 and 10 μg per vial. The number of individuals that survived these concentrations increased each of the first 3 yrs, and then fluctuated from year to year. In some cases, moths with increased tolerance to cypermethrin occurred in locations where little or no pyrethroid insecticides were used for bollworm control. A likely explanation for tolerant bollworms in Missouri is immigration from more southerly locations, and evidence for long range dispersal of these insects is presented. Implications for regional resistance monitoring also are discussed. DA - 1998/7// PY - 1998/7// DO - 10.18474/0749-8004-33.3.300 VL - 33 IS - 3 SP - 300-312 SN - 0749-8004 KW - Helicoverpa zea KW - cypermethrin KW - adult KW - resistance monitoring ER - TY - JOUR TI - Laboratory and field evaluations of Oviposition responses of Aedes albopictus and Aedes triseriatus (Diptera : Culicidae) to oak leaf infusions AU - Trexler, JD AU - Apperson, CS AU - Schal, C T2 - JOURNAL OF MEDICAL ENTOMOLOGY AB - Organic infusions created by fermenting white oak (Quercus alba L.) leaves in water were evaluated as sources of attractant odorants and contact oviposition stimulants for gravid Aedes albopictus (Skuse) and Aedes triseriatus (Say). Infusions were bioassayed in the laboratory by giving single females a choice of ovipositing in 1 container with infusion and 7 containers with water. Ae. albopictus laid significantly more eggs in containers with infusion, regardless of concentration (dilutions ranging from 10 to 100%) or age (fermentation periods of 7, 28, 60 d), than in containers holding water. The largest proportion of eggs (76.8%) was deposited in response to a 60% concentration of 7-d-old infusion. In contrast, Ae. triseriatus exhibited variable oviposition responses but generally deposited the largest number of eggs in only a few concentrations of older age infusions. In binary "sticky screen" bioassays, there was no difference between the numbers of females attracted to infusion or water, indicating that oviposition responses to infusion were mediated by contact chemostimulants rather than by attraction to odorants. Oviposition responses to infusions by field populations of Ae. albopictus and Ae. triseriatus in Raleigh, NC, were evaluated with pairs of oviposition traps, one containing infusion and the other containing water. Generally, Ae. albopictus laid significantly more eggs in ovitraps containing infusion regardless of its age (7, 28, and 60 d old) or the mass of leaves fermented (126 g = 1x or 504 g = 4x) than in water. In contrast, Ae. triseriatus deposited an equivalent number of eggs in traps containing water or 1x, 80% infusion regardless of its age; however, the oviposition response to ovitraps containing 4x, 7-d-old, 50% infusion was significant. Placement of an automobile tire behind an ovitrap did not increase the number of Ae. albopictus eggs laid in ovitraps containing 4x, 7-d-old, 50% infusion or water relative to ovitraps without a tire. Our research indicates that baiting ovitraps with oak leaf infusion would increase the sensitivity of surveillance efforts for Ae. albopictus and Ae. triseriatus. DA - 1998/11// PY - 1998/11// DO - 10.1093/jmedent/35.6.967 VL - 35 IS - 6 SP - 967-976 SN - 0022-2585 KW - Aedes albopictus KW - Aedes triseriatus KW - oviposition KW - infusion KW - oviposition trap ER - TY - JOUR TI - Increased ovipositional attractancy to surfactant-treated broccoli by the diamondback moth (Lepidoptera : Plutellidae): Tests of potential mechanisms AU - Riggin-Bucci, TM AU - Gould, F AU - White, C T2 - JOURNAL OF ENTOMOLOGICAL SCIENCE AB - Studies were conducted to investigate potential mechanisms by which treatment of broccoli leaves with the surfactant Latron CS-7® causes increased diamondback moth, Plutella xylostella (L.), oviposition. The importance of vision on oviposition was investigated by use of choice and no-choice tests conducted in the presence of light and in complete darkness. Females oviposited 10.7 and 12.8 times as many eggs on treated plants relative to nontreated plants in the presence and absence of light, respectively, indicating that females do not prefer treated plants based solely on visual cues. Greenhouse studies showed that moths continue to lay significantly more eggs on surfactant-treated plants up to 3 d after initial treatment of plants with Latron CS-7. No difference was observed in larval development or survival on treated versus nontreated plants. Scanning electron microscopy indicated a dramatic difference in wax crystallite morphology of surfactant-treated plants relative to nontreated plants. Ovipositional attractancy of surfactant-treated leaves to diamondback moths could be due to a change in mechanoreceptor cues on the leaf surface or volatile compounds released from the leaf surface as a result of altered plant wax micromorphology. DA - 1998/7// PY - 1998/7// DO - 10.18474/0749-8004-33.3.261 VL - 33 IS - 3 SP - 261-269 SN - 0749-8004 KW - Plutella xylostella KW - oviposition KW - spray adjuvants KW - behavior KW - Brassica ER - TY - JOUR TI - Expression of CCAAT/enhancer binding proteins (C/EBP) is associated with squamous differentiation in epidermis and isolated primary keratinocytes and is altered in neoplasms AU - Oh, HS AU - Smart, RC T2 - JOURNAL OF INVESTIGATIVE DERMATOLOGY AB - The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that undergo sequential changes in gene expression during differentiation. CCAAT/enhancer binding proteins (C/EBP) are members of the bZIP family of DNA binding proteins/transcription factors. Northern analysis demonstrated that C/EBPα, C/EBPβ, and C/EBPδ mRNA are expressed in mouse epidermis and their mRNA levels were generally greater than those observed in other tissues known to express high levels of C/EBP. Western analysis of isolated epidermal cell nuclei demonstrated the presence of a 42 and 30 kDa C/EBPα protein and 35 kDa C/EBPβ protein. Immunohistochemical localization of C/EBPα and C/EBPβ in intact interfollicular epidermis revealed that C/EBPβ expression is exclusive to the nuclei of a three-cell cluster of suprabasal keratinocytes that is morphologically consistent with the central column of the epidermal proliferative unit, and that C/EBPα is expressed in the nuclei and cytoplasm of suprabasal keratinocytes and weakly expressed in a perinuclear manner in some basal keratinocytes. In squamous cell carcinomas the expression of C/EBPα and C/EBPβ was greatly diminished as both the intensity of nuclear staining and the number of cells expressing C/EBPα and C/EBPβ were reduced. In isolated primary mouse keratinocytes, calcium-induced differentiation was accompanied by specific temporal changes in the expression of C/EBPα, C/EBPβ, and C/EBPδ mRNA and C/EBPα and C/EBPβ protein. These results implicate a role for the C/EBP family in the regulation of genes involved in or specifically expressed during the process of squamous differentiation in epidermis. The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that undergo sequential changes in gene expression during differentiation. CCAAT/enhancer binding proteins (C/EBP) are members of the bZIP family of DNA binding proteins/transcription factors. Northern analysis demonstrated that C/EBPα, C/EBPβ, and C/EBPδ mRNA are expressed in mouse epidermis and their mRNA levels were generally greater than those observed in other tissues known to express high levels of C/EBP. Western analysis of isolated epidermal cell nuclei demonstrated the presence of a 42 and 30 kDa C/EBPα protein and 35 kDa C/EBPβ protein. Immunohistochemical localization of C/EBPα and C/EBPβ in intact interfollicular epidermis revealed that C/EBPβ expression is exclusive to the nuclei of a three-cell cluster of suprabasal keratinocytes that is morphologically consistent with the central column of the epidermal proliferative unit, and that C/EBPα is expressed in the nuclei and cytoplasm of suprabasal keratinocytes and weakly expressed in a perinuclear manner in some basal keratinocytes. In squamous cell carcinomas the expression of C/EBPα and C/EBPβ was greatly diminished as both the intensity of nuclear staining and the number of cells expressing C/EBPα and C/EBPβ were reduced. In isolated primary mouse keratinocytes, calcium-induced differentiation was accompanied by specific temporal changes in the expression of C/EBPα, C/EBPβ, and C/EBPδ mRNA and C/EBPα and C/EBPβ protein. These results implicate a role for the C/EBP family in the regulation of genes involved in or specifically expressed during the process of squamous differentiation in epidermis. enhancer binding protein epidermal proliferative unit The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that undergo a highly coordinated program of sequential changes in gene expression during differentiation from proliferating basal cells through morphologically distinct suprabasal cells, ending in the nonviable cornified stratum corneum (Watt, 1989Watt F.M. Terminal differentiation of epidermal keratinocytes.Curr Opin Cell Biol. 1989; 1: 1107-1115Crossref PubMed Scopus (214) Google Scholar; Fuchs, 1990Fuchs E. Epidermal differentiation: the bare essentials.J Cell Biol. 1990; 111: 2807-2814Crossref PubMed Scopus (568) Google Scholar). The expression of catalytic proteins such as transglutaminase (Thacher and Rice, 1985Thacher S.M. Rice R.H. Keratinocyte-specific transglutaminase of cultured human epidermal cells: relation to cross-linked envelope formation and terminal differentiation.Cell. 1985; 40: 685-695Abstract Full Text PDF PubMed Scopus (384) Google Scholar), assembly proteins such as filaggrin (Dale et al., 1985Dale B.A. Resing K.A. Lonsdale-Eccles J.D. Filaggrin: a keratin filament associated protein.Ann NY Acad Sci. 1985; 455: 330-342Crossref PubMed Scopus (131) Google Scholar), and structural proteins such as loricrin (Mehrel et al., 1990Mehrel T. Hohl D. Rothnagel J.A. et al.Identification of a major keratinocyte cell envelope protein, loricrin.Cell. 1990; 61: 1103-1112Abstract Full Text PDF PubMed Scopus (360) Google Scholar), keratins (Fuchs and Green, 1980Fuchs E. Green H. Changes in keratin gene expression during terminal differentiation of the keratinocyte.Cell. 1980; 19: 1033-1042Abstract Full Text PDF PubMed Scopus (779) Google Scholar), involucrin (Simon and Green, 1984Simon M. Green H. Participation of membrane-associated proteins in the formation of the cross-linked envelope of the keratinocyte cell.Cell. 1984; 36: 827-834Abstract Full Text PDF PubMed Scopus (183) Google Scholar), and cornifin-α/SPRR1 (Gibbs et al., 1993Gibbs S. Fijneman R. Wiegant J. van Kessel A.D. van De Putte P. Backendorf C. Molecular characterization and evolution of the SPRR family of keratinocyte differentiation markers encoding small proline-rich proteins.Genomics. 1993; 16: 630-637Crossref PubMed Scopus (176) Google Scholar; Owens et al., 1996Owens D.M. Zainal T.A. Jetten A.M. Smart R.C. Localization and expression of cornifin-α/SPRR1 in mouse epidermis, anagen hair follicles, and skin neoplasms.J Invest Dermatol. 1996; 106: 647-654Crossref PubMed Scopus (21) Google Scholar), is strictly regulated as a function of the stage of keratinocyte differentiation. The induction of certain differentiation responsive genes is tightly coupled with the repression of others during differentiation. In addition to undergoing a precisely defined program of differentiation, keratinocytes are a rich source of numerous cytokines such as IL-1α, IL-6, IL-7, IL-8, granulocyte macrophage-colony stimulating factor (GM-CSF), and tumor necrosis factor-α that can regulate the function of cells in skin (for review, see Matsue et al., 1992Matsue H. Cruz Jr., P.D. Bergstresser P.R. Takashima A. Cytokine expression by epidermal cell subpopulations.J Invest Dermatol. 1992; 99: 42S-45SAbstract Full Text PDF PubMed Scopus (77) Google Scholar). These epidermal cytokines can act as autocrine and paracrine factors that may play a role in amplifying responses of the skin to various stimuli such as chemicals and UV light. Although cytokine expression in keratinocytes and the coordinate and sequential alterations in specific genes involved in keratinocyte differentiation have been well characterized, the transcription factors that regulate these processes in keratinocytes are largely uncharacterized. CCAAT/enhancer binding protein α (C/EBPα) is a heat-stable transcription factor that recognizes consensus sequence (5′-ATTGCGCAAT-3′) within many promoters (Vinson et al., 1989Vinson C.R. Sigler P.B. McKnight S.L. Scissors-Grip model for DNA recognition by a family of leucie zipper proteins.Science. 1989; 246: 911-916Crossref PubMed Scopus (717) Google Scholar; Johnson, 1993Johnson P.F. Identification of C/EBP basic region resodues involved in DNA sequence recognition and half-site spacing preference.Mol Cell Biol. 1993; 13: 6919-6930Crossref PubMed Scopus (101) Google Scholar). The C/EBP family contains at least seven members that include C/EBPα, C/EBPβ (also termed NF-IL6, NF-M, IL-6DBP, CRP2, or LAP), C/EBPδ (NF-IL6β or CRP3), C/EBPγ (Ig/EBP-1), CRP1, d/CEBP, and CHOP10 (GADD153) (for review, see Wedel and Loms Ziegler-Heitbrock, 1995Wedel A. Loms Ziegler-Heitbrock H.W. The C/EBP family of transcription factors.Immunobiol. 1995; 193: 171-185Crossref PubMed Scopus (195) Google Scholar). C/EBP proteins are members of the bZIP family of DNA-binding proteins and consist of three structural components: a C-terminal leucine zipper, a basic DNA-binding region (Landschulz et al., 1988Landschulz W.H. Johnson P.F. McKnight S.L. The leucine zipper: A hypothetical structure common to a new class of DNA binding proteins.Sci. 1988; 240: 1759-1764Crossref PubMed Scopus (2465) Google Scholar; Vinson et al., 1989Vinson C.R. Sigler P.B. McKnight S.L. Scissors-Grip model for DNA recognition by a family of leucie zipper proteins.Science. 1989; 246: 911-916Crossref PubMed Scopus (717) Google Scholar), and an N-terminal transactivating region (Friedman and McKnight, 1990Friedman A.D. McKnight S.L. Identification of two polypeptide segments of CCAAT/enhancer-binding protein required fot transcriptional activation of the serum albumin gene.Genes Dev. 1990; 4: 1416-1426Crossref PubMed Scopus (123) Google Scholar). C/EBP proteins share amino acid sequence similarities within their C-terminal basic region/leucine zipper domain. The leucine zipper domain is responsible for dimerization, whereas the basic region is responsible for binding to specific DNA sequences (Vinson et al., 1989Vinson C.R. Sigler P.B. McKnight S.L. Scissors-Grip model for DNA recognition by a family of leucie zipper proteins.Science. 1989; 246: 911-916Crossref PubMed Scopus (717) Google Scholar). Both homo- and heterodimers of C/EBP isoforms can form and bind to C/EBP sites within the promoters/enhancers of certain genes (Friedman et al., 1989Friedman A.D. Landschulz W.H. McKnight S.L. CCAAT/enhancer binding protein activates the promoter of the serum albumin gene in cultured hepatoma cells.Genes Dev. 1989; 3: 1314-1322Crossref PubMed Scopus (360) Google Scholar; Descombes et al., 1990Descombes P. Chojkier M. Lichisteiner S. Falvey E. Schibler U. LAP, a novel member of the C/EBP gene family, encodes a liver-enriched transcriptional activator protein.Genes Dev. 1990; 4: 1541-1551Crossref PubMed Scopus (410) Google Scholar; Cao et al., 1991Cao Z. Umek R.M. Mcnight S.L. Regulated espression of three C/EBP isoforms during adipose conversion of 3T3-L1 cells.Genes Dev. 1991; 5: 1538-1552Crossref PubMed Scopus (1297) Google Scholar; Williams et al., 1991Williams S.C. Cantwell C.A. Johnson P.F. A family of C/EBP-related proteins capable of forming covalently linked leucine zipper dimers in vitro.Genes Dev. 1991; 5: 1553-1567Crossref PubMed Scopus (434) Google Scholar). The expression of C/EBP isoforms is most prominent in adipocytes, hepatocytes, intestinal tissues, lung (Birkenmeier et al., 1989Birkenmeier E.H. Gwynn B. Howard S. Jerry J. Gordon J.I. Landschulz W.H. McKinght S.L. Tissue-specific expression, developmental regulation, and genetic mapping of the gene encoding CCAAT/enhancer binding protein.Genes Dev. 1989; 3: 1146-1156Crossref PubMed Scopus (457) Google Scholar; Cao et al., 1991Cao Z. Umek R.M. Mcnight S.L. Regulated espression of three C/EBP isoforms during adipose conversion of 3T3-L1 cells.Genes Dev. 1991; 5: 1538-1552Crossref PubMed Scopus (1297) Google Scholar), monocytes/macrophage (Natsuka et al., 1992Natsuka S. Akira S. Nishio Y. Hashimoto S. Sugita T. Isshiki H. Kishimoto T. Macrophage differentiation specific expression of NF-IL6, a transcription factor for IL-6.Blood. 1992; 79: 460-466Crossref PubMed Google Scholar), and ovarian follicles (Piontkewitz et al., 1993Piontkewitz Y. Enerback S. Hedin L. Expression and hormonal regulation of the CCAAT/enhancer binding protein-α during differentiation of rat ovarian follicles.Endocrinol. 1993; 133: 2327-2333Crossref PubMed Scopus (37) Google Scholar). C/EBPα is produced in tissues capable of gluconeogenesis and lipogenesis, especially liver and fat (Birkenmeier et al., 1989Birkenmeier E.H. Gwynn B. Howard S. Jerry J. Gordon J.I. Landschulz W.H. McKinght S.L. Tissue-specific expression, developmental regulation, and genetic mapping of the gene encoding CCAAT/enhancer binding protein.Genes Dev. 1989; 3: 1146-1156Crossref PubMed Scopus (457) Google Scholar), and it is considered to play a direct role in regulating transcription of some of the enzymes involved in controlling these metabolic processes (McKnight et al., 1989McKnight S.L. Lane M.D. Gluecksohn-Waelsch S. Is CCAAT/enhancer-binding protein a central regulator of energy metabolism?.Genes Dev. 1989; 3: 2021-2024Crossref PubMed Scopus (190) Google Scholar). Many lines of evidence indicate that C/EBPα plays a key role in the differentiation of preadipocytes into adipocytes as it appears to function both by inhibiting the clonal expansion that precedes adipocyte terminal differentiation and by activating the coordinate expression of a group of adipocyte genes whose promoters possess C/EBP-binding sites (Christy et al., 1989Christy R.J. Yang V.W. Ntambi J.M. et al.Differentiation-induced gene expression in 3T3-L1 preadipocytes: CCAAT/enhancer binding protein interacts with and activates the promoters of two adipocyte-specific genes.Genes Dev. 1989; 3: 1323-1335Crossref PubMed Scopus (453) Google Scholar; Cao et al., 1991Cao Z. Umek R.M. Mcnight S.L. Regulated espression of three C/EBP isoforms during adipose conversion of 3T3-L1 cells.Genes Dev. 1991; 5: 1538-1552Crossref PubMed Scopus (1297) Google Scholar; Umek et al., 1991Umek R.M. Friedman A.D. McKnight S.L. CCAAT-enhancer binding protein: A component of a differentiation switch.Science. 1991; 251: 288-292Crossref PubMed Scopus (561) Google Scholar; Freytag et al., 1994Freytag S.O. Paielli D.L. Gilbert J.D. Ectopic expression of the CCAAT/enhancer-binding protein a promotes the adipogenic program in a variety of mouse fibroblastic cells.Genes Dev. 1994; 8: 1654-1663Crossref PubMed Scopus (377) Google Scholar). Recent studies indicate that C/EBPα inhibits cell proliferation of fibrosarcoma cells through the upregulation of the cyclin-dependent kinase inhibitor, p21 (Timchenko et al., 1996Timchenko N.A. Wilde M. Nakanishi M. Smith J.R. Darlington G.J. CCAAT/enhancer-binding protein α (C/EBPα) inhibits cell proliferation through the p21 (WAF-1/CIP-1/SDI-1) protein.Genes Dev. 1996; 10: 804-815Crossref PubMed Scopus (341) Google Scholar). C/EBPβ plays a role at the early stages of preadipocyte differentiation and leads to the expression of C/EBPα, after which C/EBPβ is downregulated as the adipocytes acquire the complete fat-specific phenotype (Cao et al., 1991Cao Z. Umek R.M. Mcnight S.L. Regulated espression of three C/EBP isoforms during adipose conversion of 3T3-L1 cells.Genes Dev. 1991; 5: 1538-1552Crossref PubMed Scopus (1297) Google Scholar; Yeh et al., 1995Yeh W.-C. Cao Z. Classon M. McKnight S.L. Cascade regulation of terminal adipocyte differentiation by three members of the C/EBP family of leucine zipper proteins.Genes Dev. 1995; 9: 168-181Crossref PubMed Scopus (784) Google Scholar). C/EBPβ is more widely expressed than C/EBPα, e.g., C/EBPβ expression increases during differentiation of macrophage, myeloid, and plasma cells (Cooper et al., 1992Cooper C. Johnson D. Roman C. Avitahl N. Tucker P. Calame K. The C/EBP family of transcriptional activators is functionally important for Ig VH promoter activity in vivo and in vitro.J Immunol. 1992; 149: 3225-3231PubMed Google Scholar; Natsuka et al., 1992Natsuka S. Akira S. Nishio Y. Hashimoto S. Sugita T. Isshiki H. Kishimoto T. Macrophage differentiation specific expression of NF-IL6, a transcription factor for IL-6.Blood. 1992; 79: 460-466Crossref PubMed Google Scholar; Scott et al., 1992Scott L.M. Civin C.I. Roth P. Friedman A.D. A novel temporal expression pattern of three C/EBP family members in differentiating myelomonocytic cells.Blood. 1992; 80: 1725-1735Crossref PubMed Google Scholar), suggesting its involvement in the differentiation of these lineages. Moreover, there is evidence that C/EBPβ is involved in the regulation of the expression of several cytokines and C/EBPβ binding motifs are found in the regulatory regions of IL-1β, IL-6, IL-8, tumor necrosis factor-α, and granulocyte-colony stimulating factor (G-CSF) (Akira et al., 1990Akira S. Issiki H. Sugita T. et al.A nuclear factor for IL-6 expression (NF-IL6) is a member of a C/EBP family.EMBO J. 1990; 9: 1897-1906Crossref PubMed Scopus (1176) Google Scholar; Mukaida et al., 1990Mukaida N. Mahe Y. Matsushima K. Cooperative interaction of NF-κB- and C/EBP-like factor binding elements in activating the interleukin-8 gene by proinflammatory cytokines.J Biol Chem. 1990; 265: 21128-21133Abstract Full Text PDF PubMed Google Scholar; Drouet et al., 1991Drouet C. Shakhov A.N. Jongeneel C.V. Enhancers and transcription factors controlling the inducibility of the tumor necrosis factor-α promoter in primary macrophages.J Immunol. 1991; 147: 1694-1700PubMed Google Scholar; Natsuka et al., 1992Natsuka S. Akira S. Nishio Y. Hashimoto S. Sugita T. Isshiki H. Kishimoto T. Macrophage differentiation specific expression of NF-IL6, a transcription factor for IL-6.Blood. 1992; 79: 460-466Crossref PubMed Google Scholar; Zhang and Rom, 1993Zhang Y. Rom W.N. Regulation of the interleukin-1β (IL-1 β) gene by mycobacterial components and lipopolysaccharide is mediated by two nuclear factor-IL6 motifs.Mol Cell Biol. 1993; 13: 3831-3837Crossref PubMed Google Scholar). Like C/EBPβ, C/EBPδ also appears to play a role at the early stages of preadipocyte differentiation (Cao et al., 1991Cao Z. Umek R.M. Mcnight S.L. Regulated espression of three C/EBP isoforms during adipose conversion of 3T3-L1 cells.Genes Dev. 1991; 5: 1538-1552Crossref PubMed Scopus (1297) Google Scholar; Yeh et al., 1995Yeh W.-C. Cao Z. Classon M. McKnight S.L. Cascade regulation of terminal adipocyte differentiation by three members of the C/EBP family of leucine zipper proteins.Genes Dev. 1995; 9: 168-181Crossref PubMed Scopus (784) Google Scholar). Recent studies have demonstrated that C/EBPδ is important for regulating the acute phase expression of the human C3 (the third component of complement) gene in the presence of IL-1 (Juan et al., 1993Juan T.S.-C. Wilson D.R. Wilde M.D. Darlington G.J. Participation of the transcription factor C/EBPδ in the acute-phase regulation of the human gene for complement component C3.Proc Natl Acad Sci USA. 1993; 90: 2584-2588Crossref PubMed Scopus (117) Google Scholar), suggesting a role of C/EBPδ in the regulation of several IL-1 target genes. As C/EBP proteins play a fundamental role in the differentiation of preadipocytes to adipocytes and in the regulation of the expression of many different genes encoding cytokines in several cell types, we reasoned that C/EBP may be expressed in epidermis and they may play an important role in differentiation and/or cytokine expression. Our results demonstrate that C/EBPα, C/EBPβ, and C/EBPδ mRNA are highly expressed in mouse epidermis and in primary keratinocytes. Furthermore, C/EBPα and C/EBPβ proteins are preferentially expressed in specific suprabasal keratinocytes in epidermis and their expression is upregulated during calcium-induced differentiation of primary keratinocytes. Antibodies for C/EBP isoforms were purchased from Santa Cruz Biotechnology (Santa Cruz, CA). Keratin 1 polyclonal antibody was purchased from Berkeley Antibody Company (Richmond, CA). Biotinylated secondary goat anti-rabbit IgG was purchased from Boehringer Mannheim (Indianapolis, IN). Peroxidase-conjugated streptavidin and 5,5′-diaminobenzidine were purchased from BioGenex (San Ramon, CA). Protease inhibitors, sodium orthovanadate, and DNAse were purchased from Sigma (St. Louis, MO). [α-32P]dCTP was purchased from DuPont-New England Nuclear Research Products (Boston, MA). Fetal bovine serum and trypsin were purchased from GIBCO BRL (Gaithersburg, MD). EMEM (Ca++ free) was purchased from BioWhittaker (Walkersville, MD). Epidermal growth factor was purchased from United States Biochemical (Cleveland, OH). Female CD-1 mice, 6–7 wk old, or pregnant CD-1 mice were purchased from Charles River Laboratories (Raleigh, NC). The mice were kept in our facility for 1 wk prior to use and were fed rodent chow (Agway Food, Granville Milling, Creedmore, NC) and water ad libitum. The mice were kept on corn cob bedding and placed on a 12 h light/dark cycle until they were used. The hair of the dorsal skin of 6–7 wk old mice was clipped with electric clippers. Epidermis was removed from the dermis (Goodell et al., 1996Goodell A.L. Oh H.-S. Meyer S.A. Smart R.C. Epidermal protein kinase C-β2 is highly sensitive to downregulation and is exculsively expressed in langerhans cells: Down regulation is associated with attenuated contact hypersensitivity.J Invest Dermatol. 1996; 107: 354-359Crossref Scopus (18) Google Scholar) and total RNA was isolated from the epidermis/other tissues or from primary mouse keratinocytes using the single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction as described previously (Chomczynski and Sacchi, 1987Chomczynski P. Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.Anal Biochem. 1987; 162: 156-159Crossref PubMed Scopus (62247) Google Scholar). Thirty micrograms of each RNA sample was subjected to electrophoresis on a 1% agarose-formaldehyde gel, transferred to a Zeta-probeGT nylon membrane (Bio-Rad, Hercules, CA), and prehybridized at 65°C for 10 min in a solution containing 0.25 M sodium phosphate buffer (pH 7.2) and 7% sodium dodesyl sulfate. Hybridization was conducted overnight at 65°C with 25 ng of 32P-labeled C/EBPα rat cDNA isolated from the pMSV-C/EBPα plasmid, a gift from Dr. S. L. McKnight (University of Texas Southwestern Medical Center, Dallas, TX). After hybridization, the membrane was washed and exposed to Kodak X-OMAT AR film in a cassette with intensifying screens at –80°C. The same membrane was stripped and reprobed with radiolabeled cornifin-α/SPRR1 cDNA, a gift from Dr. A.M. Jetten (National Institute of Environmental Health Sciences, Research Triangle Park, NC), 7S RNA cDNA, a gift from Dr. A. Balmain (The Beatson Institute for Cancer Research, Glasgow, U.K.), or polymerase chain reaction cloned mouse genes corresponding to C/EBPβ and C/EBPδ. Mouse genomic DNA was utilized to polymerase chain reaction clone the intronless C/EBPβ and C/EBPδ genes using the following forward and reverse primer for C/EBPβ, 5′-TTCTACTACGAGCCCGACTGCC-3′ and 5′-CAGCTTGTCCACCGTCTTCTTG-3′, respectively, and the following forward and reverse primers for C/EBPδ, 5′-CCAGATTTTCATTTCGCTCCAG-3′ and 5′-TCGCAGGTCCCAAAGAAACTAG-3′, respectively. The identity of C/EBPβ and C/EBPδ polymerase chain reaction products was confirmed by the size of the amplified product and restriction enzyme analysis. 7S RNA cDNA was used to confirm that equal amounts of RNA were loaded (Balmain et al., 1982Balmain A. Krumlauf R. Vass J.K. Birnie G.D. Cloning and characterization of the abundant cytoplasmic 7S RNA from mouse cells.Nucl Acids Res. 1982; 10: 4259-4277Crossref PubMed Scopus (147) Google Scholar). All cDNA were radiolabeled by random priming using a random priming kit (GIBCO BRL) and [α-32P]dCTP (3000 Ci per mmol, 10 μCi per μl) and purified from unincorporated [α-32P]dCTP using Push Columns (Stratagene, La Jolla, CA). The preparation of epidermal cells from mouse skin was performed as described by Goodell et al., 1996Goodell A.L. Oh H.-S. Meyer S.A. Smart R.C. Epidermal protein kinase C-β2 is highly sensitive to downregulation and is exculsively expressed in langerhans cells: Down regulation is associated with attenuated contact hypersensitivity.J Invest Dermatol. 1996; 107: 354-359Crossref Scopus (18) Google Scholar. The epidermal cell nuclei were isolated as described by Chapin et al., 1994Chapin R.B. Brady P.S. Barke R.A. Brady L.J. Hepatic CCAAT/enhancer binding protein (C/EBP-α and C/EBP-β) expression changes with riboflavin deficiency, diet restriction and starvation in rats.J Nutr. 1994; 124: 2365-2375Google Scholar. The nuclei were resuspended in RIPA buffer [phosphate buffered saline (PBS) containing 1% Nonidet P-40, 0.5% sodium deoxycholic acid, and 0.1% sodium dodecyl sulfate] with protease inhibitors (100 μg aprotinin per ml and 0.1 mM phenylmethylsulfonyl fluoride) and tyrosine phosphatase inhibitor (1 mM sodium orthovanadate). The resuspension was sonicated, incubated on ice for 1 h, and subjected to centrifugation for 20 min at 4°C, 11,000 × g. In some experiments, epidermal cells or primary keratinocytes were placed in the above buffer, sonicated, incubated on ice for 1 h, and subjected to centrifugation for 20 min at 4°C, 11,000 × g. The supernatant was stored at –80°C prior to analysis and the protein concentration was determined using the Lowry method (Lowry et al., 1951Lowry O.H. Rosebrough N.J. Farr A.L. Randall R.J. Protein determination with folin phenol reagent.J Biol Chem. 1951; 193: 265-275Abstract Full Text PDF PubMed Google Scholar). Epidermal homogenate, C/EBPα and C/EBPβ standard proteins, and molecular weight markers (GIBCO BRL) were boiled in sodium dodecyl sulfate sample loading buffer for 4 min and subjected to reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis through Tris-Glycine gels. The C/EBPα and C/EBPβ standard proteins were gifts from Drs. Peter Johnson and Esta Sterneck (National Cancer Institute, Bethesda, MD). The separated proteins were electrophorectically transferred to an Immobilon P membrane (Millipore, Bedford, MA). Following incubation in blocking buffer (PBS with 1% bovine serum albumin, 5% milk, and 0.1% Tween) for 1 h at room temperature, the membranes were probed overnight at 4°C with rabbit polyclonal IgG raised against C/EBPα (1:5000), C/EBPβ (1:2500), keratin 1 AF109 (1:500), or cornifin-α/SPRR1 (1:5000), a gift from Dr. A.M. Jetten (National Institute of Environmental Health Sciences, Research Triangle Park, NC). The membranes were then probed with a horseradish peroxidase-linked donkey anti-rabbit Ig (Amersham, Arlington Heights, IL) for 1 h at room temperature. Detection was made with a luminol system (ECL system, Amersham), and the resulting light was then recorded on to Kodak BioMax MR film. Upon completion of autoradiography, membranes were stained with amido black to confirm equal protein content in all the lanes. Skin samples (n = 5), 7,12-dimethylbenz[a]anthracene-initiated/12-O-tetradecanoylphorbol-13-acetate-promoted squamous papillomas (n = 8), and squamous cell carcinomas (n = 4) were frozen in OCT compound (Miles, Elkhart, IN). Frozen sections (5 μm) on Super Frost Plus slides (Fisher, Pittsburgh, PA) were air dried for 30 min at room temperature and fixed in ice-cold acetone for 10 min on ice followed by rinsing in three changes of PBS. The endogenous peroxidase activity was quenched by incubation in 0.1% H2O2 in PBS for 10 min at room temperature. After rinsing in three changes of PBS, the nonspecific binding of antibodies was blocked by incubating the sections in 1% normal goat serum in PBS for 30 min at room temperature. The excessive blocking solution was drained and the sections were then incubated with the primary polyclonal antibodies against C/EBPα (1:25,000) and C/EBPβ (1:10,000) in 1% bovine serum albumin in PBS at 4°C overnight. After washing with PBS, the samples were incubated with a biotinylated goat-anti-rabbit IgG for 30 min at room temperature followed by a 30 min incubation with peroxidase conjugated streptavidin. The avidin/biotin-peroxidase complexes were visualized by incubation with 5,5′-diaminobenzidine (following the manufacturer’s protocol). The sections were counterstained lightly with Harris-modified hematoxylin, dehydrated, and permounted with cover glasses. No C/EBP isoform staining was observed when the primary antibody was omitted and the control rabbit serum was applied. Primary keratinocytes were isolated from newborn CD-1 mice (1–2 d old) by trypsin floatation (Hennings et al., 1980Hennings H. Michael D. Cheng C. Steinert P. Holbrook K. Yuspa S.H. Calcium regulation of growth and differentiation of mouse epidermal cells in culture.Cell. 1980; 19: 245-254Abstract Full Text PDF PubMed Scopus (1448) Google Scholar). Isolated epidermal cells were plated at 6 × 106 cells per 60 mm plate in Ca++ free EMEM supplemented with 10% fetal bovine serum and 4 ng epidermal growth factor per ml for 4 h to enhance keratinocyte attachment. Cells were then gently washed with Mg++ and Ca++ free PBS twice to remove any remaining calcium and then cultured in Ca++ free EMEM supplemented with 8% chelex-treated fetal bovine serum and 4 ng epidermal growth factor per ml. Calcium chloride was then added to produce a final concentration of 0.05 mM Ca++. After 3 d in culture, calcium chloride was added to produce a final concentration 0.12 mM Ca++ or 1.5 mM Ca++ (Yuspa et al., 1989Yuspa S.H. Kilkenny A.E. Steinert P.M. Roop D.R. Expression of murine epidermal differentiation markers is tightly regulated by restricted extracellular calcium concentrations in vitro.J Cell Biol. 1989; 109: 1207-1217Crossref PubMed Scopus (488) Google Scholar). At various times, keratinocytes were harvested for the isolation of protein and RNA for western and northern analysis, respectively. In order to determine whether C/EBPα, C/EBPβ, and C/EBPδ mRNA are expressed in mouse epidermis, total RNA was isolated from the epidermis and northern blot analysis was conducted. For comparison purposes, northern analysis was also conducted on total RNA isolated from several other organs or tissues known to express specific isoforms of C/EBP (Birkenmeier et al., 1989Birkenmeier E.H. Gwynn B. Howard S. Jerry J. Gordon J.I. Landschulz W.H. McKinght S.L. Tissue-specific expression, developmental regulation, and genetic mapping of the gene encoding CCAAT/enhancer binding protein.Genes Dev. 1989; 3: 1146-1156Crossref PubMed Scopus (457) Google Scholar; Cao et al., 1991Cao Z. Umek R.M. Mcnigh DA - 1998/6// PY - 1998/6// DO - 10.1046/j.1523-1747.1998.00199.x VL - 110 IS - 6 SP - 939-945 SN - 0022-202X KW - cytokines KW - skin KW - transcription factor ER - TY - JOUR TI - Analysis of xylem formation in pine by cDNA sequencing AU - Allona, I AU - Quinn, M AU - Shoop, E AU - Swope, K AU - St Cyr, S AU - Carlis, J AU - Riedl, J AU - Retzel, E AU - Campbell, MM AU - Sederoff, R AU - Whetten, RW T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - Secondary xylem (wood) formation is likely to involve some genes expressed rarely or not at all in herbaceous plants. Moreover, environmental and developmental stimuli influence secondary xylem differentiation, producing morphological and chemical changes in wood. To increase our understanding of xylem formation, and to provide material for comparative analysis of gymnosperm and angiosperm sequences, ESTs were obtained from immature xylem of loblolly pine ( Pinus taeda L.). A total of 1,097 single-pass sequences were obtained from 5′ ends of cDNAs made from gravistimulated tissue from bent trees. Cluster analysis detected 107 groups of similar sequences, ranging in size from 2 to 20 sequences. A total of 361 sequences fell into these groups, whereas 736 sequences were unique. About 55% of the pine EST sequences show similarity to previously described sequences in public databases. About 10% of the recognized genes encode factors involved in cell wall formation. Sequences similar to cell wall proteins, most known lignin biosynthetic enzymes, and several enzymes of carbohydrate metabolism were found. A number of putative regulatory proteins also are represented. Expression patterns of several of these genes were studied in various tissues and organs of pine. Sequencing novel genes expressed during xylem formation will provide a powerful means of identifying mechanisms controlling this important differentiation pathway. DA - 1998/8/4/ PY - 1998/8/4/ DO - 10.1073/pnas.95.16.9693 VL - 95 IS - 16 SP - 9693-9698 SN - 0027-8424 ER - TY - JOUR TI - The soybean cyst nematode, Heterodera glycines: a genetic model system for the study of plant-parasitic nematodes AU - Opperman, CH AU - Bird, DM T2 - CURRENT OPINION IN PLANT BIOLOGY AB - Despite advances in understanding plant responses to nematode infection, little information exists regarding parasitic mechanisms. Recently, it has become possible to perform genetic analysis of soybean cyst nematode. Integration of classic and reverse genetics and genomic approaches for the parasite, with host genetics and genomics will expand our knowledge of nematode parasitism. DA - 1998/8// PY - 1998/8// DO - 10.1016/1369-5266(88)80057-8 VL - 1 IS - 4 SP - 342-346 SN - 1369-5266 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0032130137&partnerID=MN8TOARS ER - TY - JOUR TI - Sustainability of transgenic insecticidal cultivars: Integrating pest genetics and ecology AU - Gould, F T2 - ANNUAL REVIEW OF ENTOMOLOGY AB - This review examines potential impacts of transgenic cultivars on insect population dynamics and evolution. Experience with classically bred, insecticidal cultivars has demonstrated that a solid understanding of both the target insect's ecology and the cultivar's performance under varied field conditions will be essential for predicting area-wide effects of transgenic cultivars on pest and natural enemy dynamics. This experience has also demonstrated the evolutionary capacity of pests for adaptive response to insecticidal traits in crops. Biochemical and genetic studies of insect adaptation to the Bacillus thuringiensis (Bt) toxins expressed by currently marketed transgenic cultivars indicate a high risk for rapid adaptation if these cultivars are misused. Theoretical and practical issues involved in implementing strategies to delay pest adaptation to insecticidal cultivars are reviewed. Emphasis is placed on examining the "high dose"/refuge strategy that has become the goal of industry and regulatory authorities. DA - 1998/// PY - 1998/// DO - 10.1146/annurev.ento.43.1.701 VL - 43 SP - 701-726 SN - 1545-4487 KW - Bacillus thuringiensis KW - resistance management KW - transgenic crops KW - host-plant resistance KW - population dynamics ER - TY - JOUR TI - Role of foliar phenolics in host plant resistance of Malus taxa to adult Japanese beetles AU - Fulcher, A. F. AU - Ranney, T. G. AU - Burton, J. D. AU - Walgenbach, J. F. AU - Danehower, D. A. T2 - HortScience DA - 1998/// PY - 1998/// VL - 33 IS - 5 SP - 862-865 ER - TY - JOUR TI - Reovirus induction of and sensitivity to beta interferon in cardiac myocyte cultures correlate with induction of myocarditis and are determined by viral core proteins AU - Sherry, B. AU - Torres, J. AU - Blum, M. A. T2 - Journal of Virology DA - 1998/// PY - 1998/// VL - 72 IS - 2 SP - 1314-1323 ER - TY - JOUR TI - Recent advances in understanding lignin biosynthesis AU - Whetten, RW AU - MacKay, JJ AU - Sederoff, RR T2 - ANNUAL REVIEW OF PLANT PHYSIOLOGY AND PLANT MOLECULAR BIOLOGY AB - After a long period of little change, the basic concepts of lignin biosynthesis have been challenged by new results from genetic modification of lignin content and composition. New techniques for making directed genetic changes in plants, as well as improvements in the analytical techniques used to determine lignin content and composition in plant cell walls, have been used in experimental tests of the accepted lignin biosynthetic pathway. The lignins obtained from genetically modified plants have shown unexpected properties, and these findings have extended the known range of variation in lignin content and composition. These results argue that the accepted lignin biosynthetic pathway is either incomplete or incorrect, or both; and also suggest that plants may have a high level of metabolic plasticity in the formation of lignins. If this is so, the properties of novel lignins could be of significant scientific and practical interest. DA - 1998/// PY - 1998/// DO - 10.1146/annurev.arplant.49.1.585 VL - 49 IS - 1998 SP - 585-609 SN - 1040-2519 KW - monolignol biosynthesis KW - lignin composition KW - pulp manufacturing KW - forage quality KW - metabolic plasticity ER - TY - JOUR TI - Purification and functional characterization of a chaperone from Methanococcus jannaschii AU - Kowalski, JM AU - Kelly, RM AU - Konisky, J AU - Clark, DS AU - Wittrup, KD T2 - SYSTEMATIC AND APPLIED MICROBIOLOGY AB - A chaperone from Methanococcus jannaschii has been purified to homogeneity with a single chromatographic step. The chaperone was identified and characterized using activity assays for characteristic chaperone abilities. The M. jannaschii chaperone binds unfolded proteins, protects proteins against heat-induced aggregation, and has a strongly temperature dependent ATPase activity. The chaperone has also been shown to inhibit the spontaneous refolding of a mesophilic protein at low temperatures. The purified chaperone complex has a M(r) of about 1,000,000 and consists of a single type of subunit with an approximate M(r) of 60,000. Analysis of partial sequence data reveals that this chaperone is the predicted protein product of the previously identified chaperonin gene in M. jannaschii (BULT et al., 1996). To our knowledge, this is the first functional characterization of a chaperone from a methanogen. DA - 1998/6// PY - 1998/6// DO - 10.1016/S0723-2020(98)80021-0 VL - 21 IS - 2 SP - 173-178 SN - 0723-2020 KW - thermophilic chaperonin KW - Methanococcus jannaschii ER - TY - PAT TI - Plant nuclear scaffold attachment region and method for increasing gene expression in transgenic cells C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Performance of three selection cycles from four slicing cucumber populations hybridized with a tester AU - Cramer, CS AU - Wehner, TC T2 - JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE AB - Recurrent selection has been used as a breeding method to improve traits having low heritability such as fruit yield, earliness, and fruit shape. The objective of this study was to measure the progress of recurrent selection in four slicing cucumber populations in terms of hybrid performance when crossed with a common tester. The four populations, North Carolina wide-base slicer (NCWBS), medium-base slicer (NCMBS), elite slicer 1 (NCES1), and Beit Alpha 1 (NCBA1) populations, which differed in their genetic diversity and mean performance, were developed using modified intrapopulation half-sib recurrent selection to improve fruit yield and quality. Eleven S 0 families were taken randomly from each of three selection cycles (early, intermediate, and advanced) from each population. Those families were self-pollinated to form S 1 families, and the S 1 families were crossed to `Poinsett 76', a popular slicing cucumber cultivar. The experiment was a splitplot treatment arrangement in a randomized complete-block design with 22 replications per population, with the four populations as whole plots and the three cycles as subplots. When 10% of fruit were oversized (>60 mm in diameter), plants were sprayed with paraquat to defoliate them for once-over harvest. Plots were evaluated for total, early, and marketable yield and fruit shape. Recurrent selection for improved fruit yield and shape per se resulted in improved hybrid performance of the NCWBS and NCBA1 populations for fruit yield and shape rating when tested in the selected or nonselected environment. The NCWBS population had the largest gain (21%) in hybrid performance averaged over all traits. In addition, early yield was improved an average of 18% from early to late cycles for each population. Even though the fruit yield and shape rating of `Dasher II' was greater than the hybrid performance of each population mean for the same traits, several F 1 families within each population exceeded the fruit yield of `Dasher II'. DA - 1998/5// PY - 1998/5// DO - 10.21273/jashs.123.3.396 VL - 123 IS - 3 SP - 396-400 SN - 0003-1062 KW - Cucumis sativus KW - cucurbitaceae KW - earliness KW - fruit shape KW - recurrent selection KW - yield ER - TY - CHAP TI - Pathogenesis of reovirus myocarditis AU - Sherry, B. T2 - Reoviruses. II, Cytopathogenicity and pathogenesis A2 - K. L. Tyler, A2 - Oldstone, M. B. A. AB - Acute myocarditis (Aretz et al. 1986) is prevalent in humans, with reports suggesting that 5%–20% of the population has suffered some form of viral myocarditis (Bandt et al. 1979; Okuni et al. 1975; Woodruff 1980). It is often fatal in infants (Cherry 1995; Kaplan et al. 1983; Martin et al. 1994). In older individuals the acute disease usually resolves but can progress to chronic myocarditis and/or dilated cardiomyopathy (Archard et al. 1991; Kandolph et al. 1991; Keeling et al. 1994; Martino et al. 1994; Matsumori and Kawai 1982; Morimoto et al. 1992; Olsen 1992; Sole and Liu 1994) with concomitant cardiac failure (Borggrefe et al. 1994; Di Lenarda et al. 1994). Enteroviruses (mainly coxsackieviruses) most likely account for 20%–50% or more of the cases (Archard et al. 1991; Bowles et al. 1986; Easton and Eglin 1988; Kandolph et al. 1987, 1991; Tracy et al. 1990a,b; Weiss et al. 1991), and there is compelling evidence that enterovirus chronic myocarditis and acute myocarditis are immune-mediated (Cook et al. 1995; Guthrie et al. 1984; Hashimoto et al. 1983; Huber 1992; Huber et al. 1988; Kishimoto and Abelmann 1990; Klingel et al. 1996; Leslie et al. 1989; Liu et al. 1995; Martino et al. 1995; Rose et al. 1988, 1992; Schwimmbeck et al. 1996; Wolfgram et al. 1985; Woodruff 1980). CN - QR414 .R47 1998 PY - 1998/// DO - 10.1007/978-3-642-72095-6_3 VL - 233 SP - 51-66 PB - New York: Springer ER - TY - JOUR TI - Novel and Highly Specific Transport of a Volatile Sex Pheromone by Hemolymph Lipophorin in Moths AU - Schal, Coby AU - Sevala, Veeresh AU - Cardé, Ring T. T2 - Naturwissenschaften DA - 1998/7/27/ PY - 1998/7/27/ DO - 10.1007/s001140050511 VL - 85 IS - 7 SP - 339-342 J2 - Naturwissenschaften OP - SN - 0028-1042 1432-1904 UR - http://dx.doi.org/10.1007/s001140050511 DB - Crossref ER - TY - PAT TI - Method of increasing expression for foreign genes in plant cells C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Ferredoxin-1 mRNA is destabilized by changes in photosynthetic electron transport AU - Petracek, ME AU - Dickey, LF AU - Nguyen, TT AU - Gatz, C AU - Sowinski, DA AU - Allen, GC AU - Thompson, WF T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - In transgenic tobacco, pea Ferredoxin-1 ( Fed-1 ) mRNA accumulates rapidly in response to photosynthesis even when the transgene is driven by a constitutive promoter. To investigate the role of photosynthesis on Fed-1 mRNA stability, we used the tetracycline repressible Top10 promoter system to specifically shut off transcription of the Fed-1 transgene. The Fed-1 mRNA has a half-life of approximately 2.4 hr in the light and a half-life of only 1.2 hr in the dark or in the presence of the photosynthetic electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). These data indicate that cessation of photosynthesis, either by darkness or DCMU results in a destabilization of the Fed-1 mRNA. Furthermore, the Fed-1 mRNA half-life is reduced immediately upon transfer to darkness, suggesting that Fed-1 mRNA destabilization is a primary response to photosynthesis rather than a secondary response to long-term dark adaptation. Finally, the two different methods for efficient tetracycline delivery reported here generally should be useful for half-life measurements of other mRNAs in whole plants. DA - 1998/7/21/ PY - 1998/7/21/ DO - 10.1073/pnas.95.15.9009 VL - 95 IS - 15 SP - 9009-9013 SN - 0027-8424 ER - TY - JOUR TI - Evaluation of oriental trellis cucumbers for production in North Carolina AU - Shetty, N. V. AU - Wehner, T. C. T2 - HortScience DA - 1998/// PY - 1998/// VL - 33 IS - 5 SP - 891-896 ER - TY - JOUR TI - Do dynamics of crop maturation and herbivorous insect life cycle influence the risk of adaptation to toxins in transgenic host plants? AU - Onstad, DW AU - Gould, F T2 - ENVIRONMENTAL ENTOMOLOGY AB - Because host-plant chemistry is dynamic, chemical defenses are dynamic, and senescence in plants causes many proteins to decompose after flowering, laboratory and field studies on transgenic crops performed over only part of a plant generation or part of a season may not provide sufficient data to evaluate strategies for resistance management. As an example, we focused on the recent introduction of transgenic corn to control European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae). We gathered data from literature on the life cycle of European corn borer and corn crop maturation to study the role that phenological relationships may play in resistance evolution. In addition, we simulated hypothetical titer declines resulting in increased survival in European corn borer populations infesting transgenic corn using a model of population dynamics and genetics. The relationship between European corn borer hatching period and corn maturation varies greatly from site to site and year to year. The peak of the hatching period in the late summer generation of the European corn borer occurs at or after the average midpoint of the dough stage of corn. The last larvae tend to hatch after the dough stage is past and after the midpoint of the dent stage. In simulations where 5% of a region is planted with nontransgenic corn in separate refuge plots and 95% is planted with transgenic corn, complete loss of titer as a result of senescence produces resistance at the 3% resistance-allele level after 5–42 yr, which is less than the 83 yr predicted by the standard model for resistance development when the transgenic corn loses no titer as a result of senescence. We hypothesize that genetically engineered toxins will often decrease in leaf and stem titer as crops reach maturation. The insects feeding and surviving on a crop during its senescence may have important consequences for the population genetics of the breakdown of host plant resistance. DA - 1998/6// PY - 1998/6// DO - 10.1093/ee/27.3.517 VL - 27 IS - 3 SP - 517-522 SN - 0046-225X KW - Ostrinia nubilalis KW - Zea mays KW - Bacillus thuringiensis KW - insecticide resistance KW - host plant resistance ER - TY - JOUR TI - Bacillus thuringiensis isolates from the Philippines: habitat distribution, delta-endotoxin diversity, and toxicity to rice stem borers (Lepidoptera : Pyralidae) AU - Theunis, W AU - Aguda, RM AU - Cruz, WT AU - Decock, C AU - Peferoen, M AU - Lambert, B AU - Bottrell, DG AU - Gould, FL AU - Litsinger, JA AU - Cohen, MB T2 - BULLETIN OF ENTOMOLOGICAL RESEARCH AB - Abstract Bacillus thuringiensis Berliner isolates were detected in 57% of 801 samples of rice grain dust, soil, rice field arthropods, and miscellaneous habitats (rice straw compost and mammal faeces) collected at 100 sites in the Philippines. The collection yielded 3950 isolates of B. thuringiensis (8.7 isolates/positive sample). Grain dust from rice mills was the richest source (63% of the samples were positive, with 10.2 isolates/positive sample), followed by rice field arthropods, soil, and miscellaneous habitats. Polyclonal antibodies to six δ-endotoxin groups (Cry1A, Cry1B, Cry1C, Cry1D, Cry1E, and Cry3A) were used in enzyme-linked immunosorbent assays (ELISA) to characterize the toxins produced by each isolate. Subsamples of isolates representing the diversity of isolate sources and δ-endotoxin profiles were bioassayed against the yellow stem borer, Scirpophaga incertulas (Walker) and striped stem borer, Chilo suppressalis (Walker). Eighteen isolates highly toxic to both species were selected for characterization of δ-endotoxin genes by polymerase chain reaction (PCR) with primers specific to 14 genes or gene subfamilies, and Western blotting with Cry2A antibodies. At least two novel δ-endotoxin genes, related to cry1B and cry1F , were detected by DNA sequencing of PCR products. DA - 1998/6// PY - 1998/6// DO - 10.1017/S0007485300025955 VL - 88 IS - 3 SP - 335-342 SN - 0007-4853 ER - TY - JOUR TI - AFLP genetic maps of Eucalyptus globulus and E-tereticornis AU - Marques, CM AU - Araujo, JA AU - Ferreira, JG AU - Whetten, R AU - DM O'Malley, AU - Liu, BH AU - Sederoff, R T2 - THEORETICAL AND APPLIED GENETICS DA - 1998/5// PY - 1998/5// DO - 10.1007/s001220050795 VL - 96 IS - 6-7 SP - 727-737 SN - 1432-2242 KW - genetic map KW - linkage KW - Eucalyptus KW - AFLP marker ER - TY - JOUR TI - Selection for resistance and tolerance to oat mosaic virus and oat golden stripe virus in hexaploid oats AU - Walker, SL AU - Leath, S AU - Murphy, JP AU - Lommel, SA T2 - PLANT DISEASE AB - Coker 716, a hexaploid oat cultivar resistant to both oat mosaic virus (OMV) and oat golden stripe virus (OGSV) was crossed to three susceptible cultivars (Brooks, Madison, and Tech) to form three individual populations. Individual breeding lines were derived from each cross in the F2 generation and tested in plots consisting of equally spaced individual hills in OMV- and OGSV-infested soils and non-infested soils to evaluate resistance and yield loss of individual lines. Foliar symptoms, harvest index, and yield loss were examined as selection criteria for resistant genotypes. The study was conducted over 2 years at two North Carolina locations that differed in soil type and climate. Multiple regression models describing yield loss in each cross due to rating, year, and location were calculated. Coefficients of multiple determination in these models ranged from 0.39 to 0.51. Yield loss ranged from 39 to 60% among different crosses. Infection by OMV and OGSV accounted for the majority of yield loss in two of the populations. Disease severity varied widely over years and locations. The results suggest that selection of lines with symptomatic tissue of 10% or less, or selection of tolerant lines, is needed for breeding progress. DA - 1998/4// PY - 1998/4// DO - 10.1094/PDIS.1998.82.4.423 VL - 82 IS - 4 SP - 423-427 SN - 0191-2917 KW - multiple regression model KW - soil-borne virus ER - TY - PAT TI - Modified urf13-T protein C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Light regulation of Fed-1 mRNA requires an element in the 5' untranslated region and correlates with differential polyribosome association AU - Dickey, L. F. AU - Petracek, M. E. AU - Nguyen, T. T. AU - Hansen, E. R. AU - Thompson, William T2 - Plant Cell DA - 1998/// PY - 1998/// DO - 10.2307/3870603 VL - 10 IS - 3 SP - 475–484 ER - TY - JOUR TI - Japanese tree improvement and forest genetics AU - McKeand, S. AU - Kurinobu, S. T2 - Journal of Forestry DA - 1998/// PY - 1998/// VL - 96 IS - 4 SP - 12-17 ER - TY - JOUR TI - Insensitivity to Ridomil Gold (Mefenoxam) found among field isolates of phytophthora capsici causing phytophthora blight on bell pepper in North Carolina and New Jersey AU - Parra, G. AU - Ristaino, Jean T2 - Plant Disease AB - Phytophthora blight caused by the pathogen Phytophthora capsici has caused economic losses in bell pepper and cucurbit fields in the U.S., and the prevalence of the disease has increased in recent years. The pathogen can be dispersed in soil, with surface water, and via splash dispersal from the soil to foliage. Management of the disease relies on modifications in cultural practices, crop rotation, and judicious use of fungicides. Disease occurred in fields that were sprayed with multiple applications of Ridomil Gold (mefenoxam) according to labeled recommendations in 1997. Mefenoxam is the active enantiomer contained in the racemic fungicide metalaxyl. Mefenoxam was widely used on bell pepper for the first time in 1997, but disease was widespread. Insensitivity to mefenoxam and metalaxyl has not been reported previously in field isolates of P. capsici. However, selection for metalaxyl insensitive isolates in the laboratory after mutagenesis has been reported. Insensitivity to metalaxyl has been reported among other Oomycete pathogens including Phytophthora infestans, Pseudoperonospora cubensis, Peronospora tabacina, Bremia lactucae, and Pythium spp. Infected plants were collected from 12 fields in North Carolina by the authors and one additional field in New Jersey (courtesy of Steve Johnston). Infected plants (10 to 30 per field) were surface disinfested in 10% bleach and plated on selective media to isolate P. capsici. Colonies of the pathogen were transferred to V8 juice agar or maintained on cornmeal agar slants. Mefenoxam-amended V8 juice agar was prepared at levels of 0, 5, and 100 ppm. Screening for sensitivity was conducted by placing agar plugs containing the pathogen onto two replicate plates of mefenoxam-amended media at each concentration. Isolates were categorized as sensitive if growth was less than 40% of the unamended control at 5 ppm. Intermediate isolates exhibited growth greater than 40% of the unamended control at 5 ppm but less than 40% of the unamended control at 100 ppm mefenoxam. Insensitive isolates exhibited growth greater than 40% of the unamended control at 100 ppm mefenoxam. Concentrations of the fungicide used to screen for insensitivity were within the range applied in the field. Thus far, 161 isolates have been screened for sensitivity. Of these, 54 isolates were classified as sensitive, 15 as intermediate, and 92 or 57% of the isolates were insensitive. Three quarters of the fields sampled contained insensitive isolates and insensitivity ranged from 11 to 80% within fields. Both A 1 and A 2 mating types were recovered from some fields and insensitive isolates occurred among both mating types. Isolates that were insensitive to mefenoxam were also insensitive to metalaxyl. A significant proportion of the isolates obtained from infected plants in fields where Ridomil Gold has been used recently were insensitive. The ability of insensitive isolates to cause disease on fungicide-treated plants will be studied in further experiments. Isolates collected between 1988 and 1994 were screened and all isolates were sensitive to metalaxyl (Ridomil 2E). A dramatic shift in populations of P. capsici to insensitivity to the new metalaxyl substitute mefenoxam has occurred in bell pepper fields in a 3-year period. DA - 1998/// PY - 1998/// DO - 10.1094/pdis.1998.82.6.711d VL - 82 IS - 6 SP - 711 ER - TY - JOUR TI - Field and laboratory evaluation of female sex pheromone for detection, monitoring, and management of brownbanded cockroaches (Dictyoptera : Blattellidae) AU - Liang, DS AU - Zhang, AJ AU - Kopanic, RJ AU - Roelofs, WL AU - Schal, C T2 - JOURNAL OF ECONOMIC ENTOMOLOGY AB - The synthetic sex pheromone of the female brown banded cockroach, Supella longipalpa (F.), was highly attractive to males in the field. Supellapyrone dispensers used in our experiments showed nearly constant pheromone release rates up to 30 d. Trapping efficacy in apartments was positively correlated with the amount of pheromone used in traps. Glue traps without pheromone captured more nymphs than did jar traps, but the latter were superior in trapping adult males using pheromone. Moreover, jar traps with pheromone caught more total cockroaches than the other 2 trap types. Two commercial baits that presumably contain attractants were compared with the female sex pheromone by using jar traps. Both attracted all life stages and both sexes of the brown banded cockroach; they increased trap catch 8-fold relative to unbaited jars. Jar traps baited with 1µg of synthetic pheromone in a slow-release formulation captured twice as many cockroaches as traps with either of the commercial baits. Combination of the food attractant and pheromone resulted in further increases in trap catch. The pheromone increased the number of adult males in all treatments by 6-28 times relative to the respective controls. Supellapyrone thus offers a powerful monitoring and pest management tool. DA - 1998/4// PY - 1998/4// DO - 10.1093/jee/91.2.480 VL - 91 IS - 2 SP - 480-485 SN - 0022-0493 KW - Supella longipalpa KW - supellapyrone KW - sex pheromone KW - trapping KW - pest detection KW - monitoring ER - TY - JOUR TI - Endocrine regulation of de novo aggregation pheromone biosynthesis in the pine engraver, Ips pini (Say) (Coleoptera : Scolytidae) AU - Tillman, JA AU - Holbrook, GL AU - Dallara, PL AU - Schal, C AU - Wood, DL AU - Blomquist, GJ AU - Seybold, SJ T2 - INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY AB - In vivo and in vitro radiotracer studies were conducted with the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae), to elucidate the relationships among feeding on host (Pinus jeffreyi Grev. & Balf.) phloem, juvenile hormone III (JH III) biosynthesis, and de novo aggregation pheromone (ipsdienol) biosynthesis. The in vivo incorporation of [1-14C]acetate into ipsdienol by male I. pini increased with increasing dose of topically-applied JH III, demonstrating the stimulatory role by JH III in de novo pheromone production. In vivo incorporation of (RS)-[2-14C]mevalonolactone into ipsdienol by male I. pini was not affected by increasing JH III dose. However, injection of [14C]mevalonolactone resulted in significantly higher levels of [14C]ipsdienol than those observed in saline-injected controls. This is direct evidence for the mevalonate-based isoprenoid pathway in de novo ipsdienol biosynthesis, and suggests that in this pathway JH III does not influence enzymatically-catalyzed reactions subsequent to the conversion of 3-hydroxy-3-methylglutaryl-coenzyme A to mevalonate. An additional in vivo [14C]acetate study demonstrated that de novo ipsdienol biosynthesis is also stimulated by feeding on host phloem. Lastly, an in vitro radiotracer study utilizing L-[methyl-3H]methionine demonstrated that feeding stimulates JH III biosynthesis by the corpora allata (CA) of male, but not female, I. pini. Analysis by radio-high pressure liquid chromatography revealed that JH III is likely the type of juvenile hormone produced by the male CA. These data support a sequence of events leading to feeding-induced de novo pheromone biosynthesis in male I. pini: (1) feeding on host phloem; (2) feeding-dependent JH III biosynthesis by the CA; and (3) JH III-stimulated de novo ipsdienol biosynthesis. DA - 1998/9// PY - 1998/9// DO - 10.1016/S0965-1748(97)00117-3 VL - 28 IS - 9 SP - 705-715 SN - 0965-1748 KW - endocrine regulation KW - de novo pheromone biosynthesis KW - pine engraver KW - Ips pini KW - ipsdienol KW - 2-methyl-6-methylene-2,7-octadien-4-ol KW - juvenile hormone KW - cis-10,11-epoxy-3,7,11-trimethyl-E2,E6-dodecadienoic acid methyl ester KW - corpora allata KW - isoprenoids ER - TY - PAT TI - DNA encoding Bacillus lichenformis PWD-1 keratinase AU - Shih, J. C. H. AU - Lin, X. AU - Miller, E. S. C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Conserved sequence and structural motifs contribute to the DNA binding and cleavage activities of a geminivirus replication protein AU - Orozco, BM AU - Hanley-Bowdoin, L T2 - JOURNAL OF BIOLOGICAL CHEMISTRY AB - Tomato golden mosaic virus (TGMV), a member of the geminivirus family, has a single-stranded DNA genome that replicates through a rolling circle mechanism in nuclei of infected plant cells. TGMV encodes one essential replication protein, AL1, and recruits the rest of the DNA replication apparatus from its host. AL1 is a multifunctional protein that binds double-stranded DNA, catalyzes cleavage and ligation of single-stranded DNA, and forms oligomers. Earlier experiments showed that the region of TGMV AL1 necessary for DNA binding maps to the N-terminal 181 amino acids of the protein and overlaps the DNA cleavage (amino acids 1–120) and oligomerization (amino acids 134–181) domains. In this study, we generated a series of site-directed mutations in conserved sequence and structural motifs in the overlapping DNA binding and cleavage domains and analyzed their impact on AL1 function in vivo and in vitro. Only two of the fifteen mutant proteins were capable of supporting viral DNA synthesis in tobacco protoplasts. In vitroexperiments demonstrated that a pair of predicted α-helices with highly conserved charged residues are essential for DNA binding and cleavage. Three sequence motifs conserved among geminivirus AL1 proteins and initiator proteins from other rolling circle systems are also required for both activities. We used truncated AL1 proteins fused to a heterologous dimerization domain to show that the DNA binding domain is located between amino acids 1 and 130 and that binding is dependent on protein dimerization. In contrast, AL1 monomers were sufficient for DNA cleavage and ligation. Together, these results established that the conserved motifs in the AL1 N terminus contribute to DNA binding and cleavage with both activities displaying nearly identical amino acid requirements. However, DNA binding was readily distinguished from cleavage and ligation by its dependence on AL1/AL1 interactions. Tomato golden mosaic virus (TGMV), a member of the geminivirus family, has a single-stranded DNA genome that replicates through a rolling circle mechanism in nuclei of infected plant cells. TGMV encodes one essential replication protein, AL1, and recruits the rest of the DNA replication apparatus from its host. AL1 is a multifunctional protein that binds double-stranded DNA, catalyzes cleavage and ligation of single-stranded DNA, and forms oligomers. Earlier experiments showed that the region of TGMV AL1 necessary for DNA binding maps to the N-terminal 181 amino acids of the protein and overlaps the DNA cleavage (amino acids 1–120) and oligomerization (amino acids 134–181) domains. In this study, we generated a series of site-directed mutations in conserved sequence and structural motifs in the overlapping DNA binding and cleavage domains and analyzed their impact on AL1 function in vivo and in vitro. Only two of the fifteen mutant proteins were capable of supporting viral DNA synthesis in tobacco protoplasts. In vitroexperiments demonstrated that a pair of predicted α-helices with highly conserved charged residues are essential for DNA binding and cleavage. Three sequence motifs conserved among geminivirus AL1 proteins and initiator proteins from other rolling circle systems are also required for both activities. We used truncated AL1 proteins fused to a heterologous dimerization domain to show that the DNA binding domain is located between amino acids 1 and 130 and that binding is dependent on protein dimerization. In contrast, AL1 monomers were sufficient for DNA cleavage and ligation. Together, these results established that the conserved motifs in the AL1 N terminus contribute to DNA binding and cleavage with both activities displaying nearly identical amino acid requirements. However, DNA binding was readily distinguished from cleavage and ligation by its dependence on AL1/AL1 interactions. tomato golden mosaic virus intergenic region rolling circle replication bean golden mosaic virus tomato yellow leaf curl virus glutathione S-transferase nucleotide(s). Tomato golden mosaic virus (TGMV)1 is a member of the geminivirus family of plant-infecting viruses characterized by twin icosahedral particles and small, single-stranded DNA genomes (reviewed in Refs. 1Timmermans M.C.P. Das O.P. Messing J. Annu. Rev. Plant Physiol. 1994; 45: 79-112Crossref Scopus (103) Google Scholar and 2Hanley-Bowdoin, L., Settlage, S. B., Orozco, B. M., Nagar, S., and Robertson, D. (1998) Crit. Rev. Plant Sci., in pressGoogle Scholar). The single-stranded DNA is converted to a double-stranded form in the nucleus of infected cells and then serves as a template for rolling circle replication (RCR; Refs. 3Saunders K. Lucy A. Stanley J. Nucleic Acids Res. 1991; 19: 2325-2330Crossref PubMed Scopus (167) Google Scholar, 4Stenger D.C. Revington G.N. Stevenson M.C. Bisaro D.M. Proc. Natl. Acad. Sci. U. S. A. 1991; 88: 8029-8033Crossref PubMed Scopus (289) Google Scholar, 5Heyraud F. Matzeit V. Kammann M. Schaefer S. Schell J. Gronenborn B. EMBO J. 1993; 12: 4445-4452Crossref PubMed Scopus (90) Google Scholar) and viral gene transcription (6Sunter G. Gardiner W.E. Bisaro D.M. Virology. 1989; 170: 243-250Crossref PubMed Scopus (53) Google Scholar, 7Sunter G. Bisaro D.M. Virology. 1989; 173: 647-655Crossref PubMed Scopus (47) Google Scholar). Geminiviruses encode only a few proteins for these processes and depend on host DNA and RNA polymerases as well as their accessory factors. These characteristics make geminiviruses excellent model systems for studying plant DNA replication and transcription mechanisms. The TGMV genome consists of two circular DNA molecules, designated as A and B (8Hamilton W.D.O. Bisaro D.M. Coutts R.H.A. Buck K.W. Nucleic Acids Res. 1983; 11: 7387-7396Crossref PubMed Scopus (92) Google Scholar). Both components have a conserved 5′ intergenic region (IR) that separates divergent open reading frames (9Bisaro D.M. Hamilton W.D.O. Coutts R.H.A. Buck K.W. Nucleic Acids Res. 1982; 10: 4913-4922Crossref PubMed Scopus (52) Google Scholar). The IR includes the plus-strand origin of replication (10Orozco B.M. Gladfelter H.J. Settlage S.B. Eagle P.A. Gentry R. Hanley-Bowdoin L. Virology. 1998; 242: 346-356Crossref PubMed Scopus (68) Google Scholar) and the promoters for leftward and rightward transcription (6Sunter G. Gardiner W.E. Bisaro D.M. Virology. 1989; 170: 243-250Crossref PubMed Scopus (53) Google Scholar, 7Sunter G. Bisaro D.M. Virology. 1989; 173: 647-655Crossref PubMed Scopus (47) Google Scholar). A directly repeated sequence in the TGMV IR is required for recognition of the plus-strand origin and negative regulation of the overlapping promoter for leftward transcription (11Fontes E.P.B. Eagle P.A. Sipe P.A. Luckow V.A. Hanley-Bowdoin L. J. Biol. Chem. 1994; 269: 8459-8465Abstract Full Text PDF PubMed Google Scholar, 12Eagle P.A. Orozco B.M. Hanley-Bowdoin L. Plant Cell. 1994; 6: 1157-1170PubMed Google Scholar). Related motifs are found in the genomes of most dicot-infecting geminiviruses (13Arguello-Astorga G.R. Guevara-Gonzalez R.G. Herrera-Estrella L.R. Rivera-Bustamante R.F. Virology. 1994; 203: 90-100Crossref PubMed Scopus (278) Google Scholar), and their roles in virus-specific replication have been confirmed for bean golden mosaic virus (BGMV) and beet curly top virus (14Fontes E.P.B. Gladfelter H.J. Schaffer R.L. Petty I.T.D. Hanley-Bowdoin L. Plant Cell. 1994; 6: 405-416Crossref PubMed Scopus (171) Google Scholar, 15Choi I.R. Stenger D.C. Virology. 1995; 206: 904-912Crossref PubMed Scopus (64) Google Scholar, 16Gladfelter H.J. Eagle P.A. Fontes E.P.B. Batts L.A. Hanley-Bowdoin L. Virology. 1997; 239: 186-197Crossref PubMed Scopus (47) Google Scholar). The IR also contains a hairpin with a 9-base pair loop sequence conserved among all geminiviruses that is cleaved during initiation and termination of RCR (5Heyraud F. Matzeit V. Kammann M. Schaefer S. Schell J. Gronenborn B. EMBO J. 1993; 12: 4445-4452Crossref PubMed Scopus (90) Google Scholar, 17Laufs J. Traut W. Heyraud F. Matzeit V. Rogers S.G. Schell J. Gronenborn B. Proc. Natl. Acad. Sci. U. S. A. 1995; 92: 3879-3883Crossref PubMed Scopus (260) Google Scholar, 18Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar). Genetic experiments established that the hairpin structure is essential for TGMV replication (18Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar). TGMV encodes two proteins, AL1 and AL3, that are required for efficient viral replication. AL1 is necessary for replication, whereas AL3 enhances viral DNA accumulation by an unknown mechanism (19Elmer J.S. Brand L. Sunter G. Gardiner W.E. Bisaro D.M. Rogers S.G. Nucleic Acids Res. 1988; 16: 7043-7060Crossref PubMed Scopus (212) Google Scholar, 20Sunter G. Hartitz M.D. Hormuzdi S.G. Brough C.L. Bisaro D.M. Virology. 1990; 179: 69-77Crossref PubMed Scopus (167) Google Scholar). AL1 is a multifunctional protein that confers virus-specific recognition to its cognate plus-strand origin (15Choi I.R. Stenger D.C. Virology. 1995; 206: 904-912Crossref PubMed Scopus (64) Google Scholar, 16Gladfelter H.J. Eagle P.A. Fontes E.P.B. Batts L.A. Hanley-Bowdoin L. Virology. 1997; 239: 186-197Crossref PubMed Scopus (47) Google Scholar, 21Jupin I. Hericourt F. Benz B. Gronenborn B. FEBS Lett. 1995; 362: 116-120Crossref PubMed Scopus (74) Google Scholar) and initiates RCR (17Laufs J. Traut W. Heyraud F. Matzeit V. Rogers S.G. Schell J. Gronenborn B. Proc. Natl. Acad. Sci. U. S. A. 1995; 92: 3879-3883Crossref PubMed Scopus (260) Google Scholar, 18Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar,22Heyraud-Nitschke F. Schumacher S. Laufs J. Schaefer S. Schell J. Gronenborn B. Nucleic Acids Res. 1995; 23: 910-916Crossref PubMed Scopus (143) Google Scholar). It also actively represses its own transcription in a virus-specific manner (12Eagle P.A. Orozco B.M. Hanley-Bowdoin L. Plant Cell. 1994; 6: 1157-1170PubMed Google Scholar, 16Gladfelter H.J. Eagle P.A. Fontes E.P.B. Batts L.A. Hanley-Bowdoin L. Virology. 1997; 239: 186-197Crossref PubMed Scopus (47) Google Scholar, 23Sunter G. Hartitz M.D. Bisaro D.M. Virology. 1993; 195: 275-280Crossref PubMed Scopus (100) Google Scholar, 24Eagle P.A. Hanley-Bowdoin L. J. Virol. 1997; 71: 6947-6955Crossref PubMed Google Scholar) and induces the expression of a host DNA synthesis protein, proliferating cell nuclear antigen, in nondividing plant cells (25Nagar S. Pedersen T.J. Carrick K. Hanley-Bowdoin L. Robertson D. Plant Cell. 1995; 7: 705-719Crossref PubMed Scopus (156) Google Scholar). Several biochemical activities have been described for AL1 in vitro. TGMV AL1 binds to double-stranded DNA at the conserved repeated motif in the plus-strand origin (11Fontes E.P.B. Eagle P.A. Sipe P.A. Luckow V.A. Hanley-Bowdoin L. J. Biol. Chem. 1994; 269: 8459-8465Abstract Full Text PDF PubMed Google Scholar, 26Fontes E.P.B. Luckow V.A. Hanley-Bowdoin L. Plant Cell. 1992; 4: 597-608Crossref PubMed Scopus (136) Google Scholar) and cleaves single-stranded DNA in the invariant sequence of the hairpin loop (18Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar). Analysis of the C1 protein of tomato yellow leaf curl virus (TYLCV), a TGMV AL1 homologue, revealed that it covalently attaches to the 5′ end of the cleaved DNA by a phosphotyrosyl bond and catalyzes ligation of the cleavage products (27Laufs J. Schumacher S. Geisler N. Jupin I. Gronenborn B. FEBS Lett. 1995; 377: 258-262Crossref PubMed Scopus (67) Google Scholar). ATPase activity has also been demonstrated for the AL1/C1 proteins from TYLCV and TGMV (28Desbiez C. David C. Mettouchi A. Laufs J. Gronenborn B. Proc. Natl. Acad. Sci. U. S. A. 1995; 92: 5640-5644Crossref PubMed Scopus (106) Google Scholar, 29Orozco B.M. Miller A.B. Settlage S.B. Hanley-Bowdoin L. J. Biol. Chem. 1997; 272: 9840-9846Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar). TGMV AL1 is involved in several protein interactions. It forms large multimeric complexes (29Orozco B.M. Miller A.B. Settlage S.B. Hanley-Bowdoin L. J. Biol. Chem. 1997; 272: 9840-9846Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar), binds AL3 (30Settlage S.B. Miller B. Hanley-Bowdoin L. J. Virol. 1996; 70: 6790-6795Crossref PubMed Google Scholar), and interacts with a maize homologue of the animal cell cycle regulatory protein, retinoblastoma (31Ach R.A. Durfee T. Miller A.B. Taranto P. Hanley-Bowdoin L. Zambriski P.C. Gruissem W. Mol. Cell. Biol. 1997; 17: 5077-5086Crossref PubMed Scopus (202) Google Scholar). The C1 protein from wheat dwarf virus also interacts with retinoblastoma proteins from human and maize (32Xie Q. Suarezlopez P. Gutierrez C. EMBO J. 1995; 14: 4073-4082Crossref PubMed Scopus (156) Google Scholar, 33Collin S. Fernandez-Lobato M. Gooding P.S. Mullineaux P.M. Fenoll C. Virology. 1996; 219: 324-329Crossref PubMed Scopus (66) Google Scholar, 34Xie Q. Sanzburgos P. Hannon G.J. Gutierrez C. EMBO J. 1996; 15: 4900-4908Crossref PubMed Scopus (195) Google Scholar). In an earlier study, we used truncated proteins produced in a baculovirus expression system to map the regions of TGMV AL1 that are responsible for DNA cleavage, DNA binding and oligomerization (29Orozco B.M. Miller A.B. Settlage S.B. Hanley-Bowdoin L. J. Biol. Chem. 1997; 272: 9840-9846Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar). These experiments showed that the DNA cleavage domain is located in the first 120 amino acids of AL1 whereas the oligomerization domain maps to the protein center between amino acids 121 and 181. DNA binding requires a larger region that fully overlaps the DNA cleavage and oligomerization domains. Based on these experiments, we proposed that additional amino acids between position 121 and 181 are necessary for AL1/DNA binding and/or that AL1 complex formation is required for DNA binding. In this study, we identified key sequence and structural motifs in the DNA binding and cleavage domains. A series of site-directed mutations in the AL1 N terminus were analyzed for their impact on function in vivo and in vitro. These studies focused on three amino acid motifs, which are conserved among all geminivirus AL1/C1 proteins and many initiator proteins from other RCR systems (35Koonin E.V. Ilyina T.V. J. Gen. Virol. 1992; 73: 2763-2766Crossref PubMed Scopus (132) Google Scholar, 36Ilyina T.V. Koonin E.V. Nucleic Acids Res. 1992; 20: 3279-3285Crossref PubMed Scopus (508) Google Scholar), and on a predicted helix-loop-helix motif in the N termini of AL1/C1 proteins of dicot-infecting geminiviruses (29Orozco B.M. Miller A.B. Settlage S.B. Hanley-Bowdoin L. J. Biol. Chem. 1997; 272: 9840-9846Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar). We also used a heterologous protein interaction domain to assess the importance of oligomerization for AL1/DNA binding and coupled DNA cleavage/ligation. The plasmid pNSB148, which contains the AL1 coding sequence in a pUC118 background, was used as the template for site-directed mutagenesis (37Kunkel T.A. Proc. Natl. Acad. Sci. U. S. A. 1985; 82: 482-492Google Scholar). The oligonucleotide primers and resulting clones are listed in Table I. The sequences of fragments containing the mutations and used for subsequent cloning were verified by DNA sequence analysis. Plant expression cassettes with the mutant AL1 coding sequences were generated by subcloning NdeI/SalI fragments (AL1 amino acids 1–120) from the mutant clones into the same sites in a wild type AL1 plant expression cassette pMON1549 (11Fontes E.P.B. Eagle P.A. Sipe P.A. Luckow V.A. Hanley-Bowdoin L. J. Biol. Chem. 1994; 269: 8459-8465Abstract Full Text PDF PubMed Google Scholar). In pMON1549, AL1 expression is under the control of the cauliflower mosaic virus 35 S promoter with a duplicated enhancer (38Kay R. Chan A. Daly M. McPherson J. Science. 1987; 236: 1299-1302Crossref PubMed Scopus (736) Google Scholar) and the 3′ end from the pea E9 rbcS gene (39Coruzzi G. Broglie R. Edwards C. Chua N.-H. EMBO J. 1984; 3: 1671-1679Crossref PubMed Scopus (208) Google Scholar). Baculovirus expression vectors coding for AL1 proteins fused to a glutathione S-transferase tag (GST-AL1) were generated by digesting the mutant plant expression cassettes with NdeI and BamHI and repairing the ends with Escherichia coli DNA polymerase I (Klenow). The fragments, which included complete AL1 coding regions, were inserted into the SmaI site of pNSB314. The pNSB314 vector contains the GST coding sequence, followed by a glycine linker, a thrombin cleavage site, and a multiple cloning site for generating in-frame fusion proteins (18Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar). The mutant GST-AL1 expression cassettes are listed in Table I.Table IAL1 mutationsMotifMutationOligonucleotideBaculovirus vectorPlant expressionHelix 1H1–1GAGAAAGTGATgCggCcgcGGACAAGGAGCACpNSB627pNSB655H1–2GTAATTGAGAAAGTacTTCTTCTTTGGACpNSB434Helix 2H2–1CTTCATGAAGCgCTgcaCAGATTgcTATGAATTTTTTGTTAATCGGpNSB628pNSB656H2–2CTCTGCAGATcTTTccGAATTTTTTGTTAATCGGpNSB629pNSB657H2–3CATCTTCATGtcGCTCTtcGCAGAcTTTTATGAATTTTTTGTTAATCGGpNSB630pNSB658Motif 1M1–1GCACTGAGGAgcgGccgcAgcATAATTTTTGGCATpNSB649pNSB652M1–2CACCTCGAGGATAcGTAAGAgcATAATTTTTGGCATTpNSB685pNSB681M1–3GACATGAGGAgcgGTAAGAAAATAATTTTTGGGGCATTpNSB686pNSB682Motif 2M2–1GAATAAGCACGgcggccgcAGGTTGCCCATCpNSB650pNSB653Motif 3M3–1GAGTATCTCCGgCTTTaTCGATGgcCGTCTTGACGTCGpNSB651pNSB654M3–2CTTTGTCGATcgcCGTCTTGACGTCGpNSB687pNSB683M3–3GAGTATCTCCGgCTTTaTCGATGTACGpNSB688pNSB684M3–4TACAAGAGTAgCTCCGgCTTTcgCGATGTACGTCTTGACpNSB741pNSB747M3–5CTCCGTCTTTaTCGATGaACGTCTTGACpNSB781pNSB779M3–6GAGTATCTCCGTCTgcaTCGATGTACGpNSB782pNSB780 Open table in a new tab Wild type and mutant GST-AL1 fusion proteins were expressed in Spodoptera frugiperda (Sf9) cells using a Tn7-based baculovirus expression system (40Luckow V.A. Lee S.C. Barry G.F. Olins P.O. J. Virol. 1993; 67: 4566-4579Crossref PubMed Google Scholar) and purified from Sf9 cell cultures by glutathione affinity chromatography according to published protocols (18Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar). Purified proteins were visualized by electrophoresis in 16% polyacrylamide-SDS gels and staining with Coomassie Brilliant Blue dye. Interactions between authentic AL1 and mutant GST-AL1 proteins were assayed by copurification on glutathione-Sepharose, followed by immunoblot analysis using AL1 polyclonal antisera (29Orozco B.M. Miller A.B. Settlage S.B. Hanley-Bowdoin L. J. Biol. Chem. 1997; 272: 9840-9846Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar, 30Settlage S.B. Miller B. Hanley-Bowdoin L. J. Virol. 1996; 70: 6790-6795Crossref PubMed Google Scholar). DNA gel shift assays were performed as described previously (18Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar). An 83-base pair EcoRI fragment containing the AL1 DNA binding motif (TGMV A positions 28–84) was isolated from pNSB378 and 3′ end-labeled using Klenow and [α-32P]dATP. The radiolabeled DNA was incubated with purified GST-AL1 fusion proteins for 1 h at room temperature at the concentrations indicated in the figure legends. The bound and free probe were resolved on 1% agarose gels, dried onto DE-81 paper, and analyzed by autoradiography. For DNA cleavage and ligation, oligonucleotides corresponding to sequences in the hairpin of the TGMV (+)-strand origin were 5′ end-labeled using polynucleotide kinase and [γ-32P]ATP. The oligonucleotides CR13 (5′-GTTTAATATTACCGGATGGCCGC) and CR33 (5′-GCGGCCATCCGTTTAATATT) were used for assays with full-length mutant and wild type AL1 proteins. For assays with truncated AL1 proteins, only one oligonucleotide, CR13 or CR34 (5′-GCGGCCATCCGTTTAATATTACCGGATGG) was radiolabeled and the cold oligonucleotide was titrated into the reactions as described in the figure legend. Approximately 5000 cpm of each labeled DNA was incubated with ∼100 ng of purified GST-AL1 fusion protein in 10 μl of cleavage buffer (25 mm Tris-HCl, pH 7.5, 75 mmNaCl, 5 mm MgCl2, 2.5 mm EDTA, 2.5 mm dithiothreitol, and 250 ng of poly(dI-dC)) at 37 °C for 30 min. The reactions were terminated by adding 6 μl of gel loading buffer (95% formamide, 20 mm EDTA, 0.05% bromphenol blue) and heating to 90 °C for 2 min. The reaction products were resolved on 15% polyacrylamide denaturing gels and analyzed by autoradiography. Protoplasts were isolated fromNicotiana tabacum NT-1 suspension cells, electroporated, and cultured according to published methods (11Fontes E.P.B. Eagle P.A. Sipe P.A. Luckow V.A. Hanley-Bowdoin L. J. Biol. Chem. 1994; 269: 8459-8465Abstract Full Text PDF PubMed Google Scholar). The transfections contained 15 μg each of replicon DNA containing a partial tandem copy of TGMV B (pTG1.4B described in Ref. 14Fontes E.P.B. Gladfelter H.J. Schaffer R.L. Petty I.T.D. Hanley-Bowdoin L. Plant Cell. 1994; 6: 405-416Crossref PubMed Scopus (171) Google Scholar), wild type or mutant AL1 expression cassette, and an AL3 plant expression cassette (pNSB46 described in Ref. 11Fontes E.P.B. Eagle P.A. Sipe P.A. Luckow V.A. Hanley-Bowdoin L. J. Biol. Chem. 1994; 269: 8459-8465Abstract Full Text PDF PubMed Google Scholar). Total DNA was extracted 3 days after transfection and analyzed for double-stranded viral DNA accumulation by DNA gel blot hybridization (11Fontes E.P.B. Eagle P.A. Sipe P.A. Luckow V.A. Hanley-Bowdoin L. J. Biol. Chem. 1994; 269: 8459-8465Abstract Full Text PDF PubMed Google Scholar). Two key steps in initiation of RCR are origin recognition and generation of a free 3′-OH for priming plus-strand DNA synthesis. TGMV AL1 mediates both of these processes by binding double-stranded DNA in a sequence-specific manner and by cleaving at a unique site in the origin. Earlier studies established that the AL1 N terminus is necessary for both activities (29Orozco B.M. Miller A.B. Settlage S.B. Hanley-Bowdoin L. J. Biol. Chem. 1997; 272: 9840-9846Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar). This region of AL1 contains several conserved sequence and structural motifs (Fig. 1), including a highly predicted pair of α-helices between amino acids 25 and 52 (29Orozco B.M. Miller A.B. Settlage S.B. Hanley-Bowdoin L. J. Biol. Chem. 1997; 272: 9840-9846Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar). The sequences of both helices are strongly conserved among dicot-infecting geminiviruses, and the second helix is amphipathic in character. This conservation suggested that the predicted α-helices may be necessary for AL1 function. To test this hypothesis, we generated four site-directed mutants of TGMV AL1 that are modified in either helix 1 or helix 2 (Fig. 1 B) and compared their activities to the wild type protein in vivo and in vitro (Fig. 1 B). The helix mutants were first tested for the ability to direct replication of TGMV B DNA in tobacco protoplasts with wild type TGMV AL3 also supplied in trans. Helix 1-mutant 2 (H1–2), which contains a S25V change and resembles the AL1 protein of the closely related geminivirus BGMV, supported wild type levels of TGMV B replication (Fig. 2 A, cf. lanes 1 and 2). In contrast, H1–1, which has alanine substitutions at three conserved charged residues in helix 1, failed to support viral DNA replication (Fig. 2 A, lane 3). The mutations in helix 2 either converted three conserved charged residues to alanine (H2–1), included a I45G change (H2–2), or altered the helix to resemble BGMV AL1 (H2–3). All helix 2 mutations abolished transient replication (Fig. 2 A, lanes 3–5). The mutant phenotypes established that, in general, the amino acid sequences of the predicted helices are essential for AL1 activity in vivo. The negative effect of the I45G replacement in H2–2, which should disrupt helix 2, suggested that the structure is also required for AL1 function. The AL1 helix mutants defective in replication assays were expressed as GST-AL1 fusion proteins in insect cells, purified by glutathione affinity chromatography, and examined for various AL1 activitiesin vitro. H1–2 was not included in these experiments because of its wild type replication phenotype. The mutant proteins were tested for DNA binding activity in gel shift assays using a radiolabeled double-stranded DNA probe that includes the TGMV AL1 DNA binding site. None of the helix mutants bound DNA (Fig. 2 B, lanes 3–6), even though wild type AL1 efficiently shifted the probe in a parallel reaction (lane 2). The mutant AL1 proteins were also tested for DNA cleavage activity using a radiolabeled, single-stranded oligonucleotide corresponding to the loop and right side of the hairpin in the plus-strand origin. Wild type GST-AL1 cleaved the 23-nt substrate to give a 10-nt radiolabeled product (Fig. 2 C, lane 2). Mutants H1–1 (Fig. 2 C, lane 3) and H2–3 (lane 6) displayed severely attenuated DNA cleavage activity, whereas H2–1 (lane 4) and H2–2 (lane 5) had no detectable activity. These results demonstrated that the predicted helices 1 and 2 are required both for DNA binding and cleavage by TGMV AL1. Helices 1 and 2 are outside of the AL1 interaction domain, and their mutation should have no effect on oligomerization if the proteins are properly expressed and folded. To verify that the failure of the AL1 helix mutants to bind and cleave DNA was not due to global misfolding, the proteins were assayed for their abilities to form oligomers with authentic AL1. Wild type GST-AL1 (Fig. 3 A, lane 1) and GST fusions of H1–1 (lane 2), H2–1 (lane 3), H2–2 (lane 4), and H2–3 (lane 5) were coexpressed with authentic AL1 in insect cells, as determined by immunoblotting of total protein extracts. Like wild type GST-AL1 (Fig. 3 A, lane 6), all of the mutant proteins copurified with authentic AL1 on glutathione-Sepharose (lanes 7–10), indicating that the helix mutations did not impair AL1/AL1 interactions and, instead, specifically affected the DNA binding and cleavage activities of AL1. The N terminus of AL1 also includes three conserved sequence motifs that are found in many RCR initiator proteins (Fig. 1; Refs. 35Koonin E.V. Ilyina T.V. J. Gen. Virol. 1992; 73: 2763-2766Crossref PubMed Scopus (132) Google Scholar and 36Ilyina T.V. Koonin E.V. Nucleic Acids Res. 1992; 20: 3279-3285Crossref PubMed Scopus (508) Google Scholar). Laufset al. (27Laufs J. Schumacher S. Geisler N. Jupin I. Gronenborn B. FEBS Lett. 1995; 377: 258-262Crossref PubMed Scopus (67) Google Scholar) showed that motif 3 corresponds to the endonucleolytic active site, but the roles of motifs 1 and 2 in RCR have not been investigated. We specifically modified these motifs in TGMV AL1 and analyzed the impact of the mutations on protein function (Fig. 1 B). In M1–1, all four motif I residues (F16LTY19) were replaced with alanine. In M1–2 and M1–3, individual aromatic residues were altered to give F16A and Y19A, respectively. The motif 2 mutant contained alanine substitutions for the core HLH sequence. Transient replication assays revealed that none of the motif 1 or 2 mutants (Fig. 4 A, lanes 2–5) supported TGMV B amplification in tobacco protoplasts, establishing that both motifs are essential for AL1 activity in vivo. To gain insight into the biochemical basis of the mutant replication phenotypes, we purified GST-AL1 fusion proteins corresponding to the motif 1 and 2 mutants from insect cells and tested them for DNA binding and cleavage in vitro. All of the mutant proteins failed to bind double-stranded DNA (Fig. 4 B, lanes 2–5). Similarly, none of the mutants had detectable single-stranded DNA cleavage activity (Fig. 4 C, lanes 2–5). In parallel assays, wild type GST-AL1 (lane 1) efficiently bound (Fig. 4 B) and cleaved (Fig. 4 C) the respective DNA probes. Protein interaction experiments (Fig. 3 B) established that M1–1 (lanes 3 and 8) and M2–1 (lanes 4 and 9) can form oligomers with wild type AL1 and, thus, are not globally misfolded. Together, these results showed that motifs 1 and 2 of TGMV AL1 are required for both DNA binding and cleavage during initiation of RCR. Motif 3 includes several conserved amino acids that may contribute to AL1 function. We generated six TGMV AL1 mutants that modified one or more residues in motif 3 and analyzed their activities in vivo and in vitro. In M3–1, alanines were substituted for the catalytic Tyr-103 and conserved Asp-107 residues. As expected, M3–1 did not support TGMV B replication in tobacco protoplasts (Fig. 5 A, lane 2) and was defective for DNA cleavage (Fig. 5 C, lane 2). Gel shift assays with M3–1 revealed that double-stranded DNA binding was also attenuated over a range of protein concentrations (Fig. 5 B, lanes 5–7), even though wild type GST-AL1 readily formed protein/DNA complexes at the same concentrations (lanes 2–4). In some experiments, low levels of DNA binding were observed with the M3–1 protein (data not shown). Protein interaction experiments showing that M3–1 can oligomerize with wild type AL1 (Fig. 3 B, lanes 5 and 10) indicated that the motif 3 mutant is not globally misfolded. The DNA binding defect of M3–1 was unexpected because of the direct involvement of motif 3 in catalysis of DNA cleavage. To better characterize the role of motif 3 and specifically Tyr-103 in DNA binding, we generated two different mutations at this position. In M3–2, Tyr-103 was changed to alanine, while M3–5 contained a phenylalanine substitution. Like M3–1, neither M3–2 or M3–5 supported viral DNA replication (Fig. 5 A, lanes 3 and 6) or cleaved DNA (Fig. 5 C, lanes 3 and 6), confirming that Tyr-103 is necessary for these processes. However, only M3–2 was impaired for DNA binding over a range of protein concentrations (Fig. 5 B, lanes 5–7), whereas M3–5 displayed wild type DNA binding properties (lanes 17–19). These results demonstrated that Tyr-103 contributes to both the DNA bind DA - 1998/9/18/ PY - 1998/9/18/ DO - 10.1074/jbc.273.38.24448 VL - 273 IS - 38 SP - 24448-24456 SN - 0021-9258 ER - TY - JOUR TI - Utility of SSRs for determining genetic similarities and relationships in maize using an agarose gel system AU - Senior, ML AU - Murphy, JP AU - Goodman, MM AU - Stuber, CW T2 - CROP SCIENCE AB - Among maize ( Zea maize L.) breeders, there is a heightened awareness of the necessity for both maintaining genetic diversity for crop improvement and improving the quality of genetic resource management. Restriction fragment length polymorphisms (RFLPs) and isozymes can serve as genetic markers for estimating divergence or diversity; however, the limited number of polymorphic isozyme loci available and the labor intensive and time consuming nature of RFLPs make their use for this purpose prohibitive. Simple sequence repeats (SSRs), when resolved using agarose gels, may be a viable and costeffective alternative to RFLPs and isozymes. Ninety‐four elite maize inbred lines, representative of the genetic diversity among lines derived from the Corn Belt Dent and Southern Dent maize races, were assayed for polymorphism at 70 SSR marker loci using agarose gels. The 365 alleles identified served as raw data for estimating genetic similarities among these lines. The patterns of genetic divergence revealed by the SSR polymorphisms were consistent with known pedigrees. A cluster analysis placed the inbred lines in nine clusters that correspond to major heterotic groups or market classes for North American maize. A unique fingerprint for each inbred line could be obtained from as few as five SSR loci. The utility of polymerase chain reaction (PCR)‐based markers such as SSRs for measuring genetic diversity, for assigning lines to heterotic groups and for genetic fingerprinting equals or exceeds that of RFLP markers, a property that may prove a valuable asset for a maize breeding program. DA - 1998/// PY - 1998/// DO - 10.2135/cropsci1998.0011183X003800040034x VL - 38 IS - 4 SP - 1088-1098 SN - 0011-183X ER - TY - JOUR TI - Thermotoga neapolitana homotetrameric xylose isomerase is expressed as a catalytically active and thermostable dimer in Escherichia coli AU - Hess, J. M. AU - Tchernajenko, V. AU - Vieille, C. AU - Zeikus, J. G. AU - Kelly, R. M. T2 - Applied and Environmental Microbiology DA - 1998/// PY - 1998/// VL - 64 IS - 7 SP - 2357-2360 ER - TY - JOUR TI - The effects of scion maturation on growth and reproduction of grafted slash pine AU - Parker, , SR AU - White, TL AU - Hodge, GR AU - Powell, GL T2 - NEW FORESTS DA - 1998/5// PY - 1998/5// DO - 10.1023/A:1006541803129 VL - 15 IS - 3 SP - 243-259 SN - 1573-5095 KW - clone banks KW - juvenility KW - pollen KW - seed orchards KW - strobili ER - TY - JOUR TI - Provenance and family variation of Pinus oocarpa grown in the Brazilian cerrado AU - Moura, VPG AU - Dvorak, WS AU - Hodge, GR T2 - FOREST ECOLOGY AND MANAGEMENT AB - A Pinus oocarpa trial with six provenances and 46 open-pollinated families was planted on a deep Oxisol in 1983, at the EMBRAPA research station near Planaltina in the cerrado region of Brazil. This trial was part of the CAMCORE, North Carolina State University, international testing program. The provenances included in the test were: Camotan; San Luiz Jilotpeque; El Castaño; La Lagunilla (Guatemala) and San Marcos and Tablazon (Honduras). The trial was assessed at 13 years of age for a number of productivity and quality traits. El Castaño had better volume, and lower incidence of forks and multistems than the other provenances. Individual tree heritability for volume, stem form and branch diameter at 13 years of age was 0.29, 0.10, and 0.13, respectively. Selecting the best 25 trees in the best families would result in an estimated genetic gain of more than 30% in the next generation. Comparison of results from this test with other CAMCORE P. oocarpa trials in Colombia and Venezuela suggest that both provenance×site and family×site interactions can be of biological importance. DA - 1998/9/16/ PY - 1998/9/16/ DO - 10.1016/S0378-1127(98)00265-5 VL - 109 IS - 1-3 SP - 315-322 SN - 1872-7042 KW - pine KW - breeding KW - selection KW - genetic gain KW - heritability KW - interspecific variation ER - TY - JOUR TI - Novel developmentally regulated phosphoinositide binding proteins from soybean whose expression bypasses the requirement for an essential phosphatidylinositol transfer protein in yeast AU - Kearns, MA AU - Monks, DE AU - Fang, M AU - Rivas, MP AU - Courtney, PD AU - Chen, J AU - Prestwich, GD AU - Theibert, AB AU - Dewey, RE AU - Bankaitis, VA T2 - EMBO JOURNAL AB - Article15 July 1998free access Novel developmentally regulated phosphoinositide binding proteins from soybean whose expression bypasses the requirement for an essential phosphatidylinositol transfer protein in yeast M. A. Kearns M. A. Kearns Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author D. E. Monks D. E. Monks Department of Crop Science, North Carolina State University, Raleigh, NC, 27695-7620 USA Search for more papers by this author M. Fang M. Fang Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author M. P. Rivas M. P. Rivas Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author P. D. Courtney P. D. Courtney Department of Crop Science, North Carolina State University, Raleigh, NC, 27695-7620 USA Search for more papers by this author J. Chen J. Chen Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, UT, 84112-5820 USA Search for more papers by this author G. D. Prestwich G. D. Prestwich Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, UT, 84112-5820 USA Search for more papers by this author A. B. Theibert A. B. Theibert Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author R. E. Dewey R. E. Dewey Department of Crop Science, North Carolina State University, Raleigh, NC, 27695-7620 USA Search for more papers by this author V. A. Bankaitis Corresponding Author V. A. Bankaitis Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author M. A. Kearns M. A. Kearns Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author D. E. Monks D. E. Monks Department of Crop Science, North Carolina State University, Raleigh, NC, 27695-7620 USA Search for more papers by this author M. Fang M. Fang Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author M. P. Rivas M. P. Rivas Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author P. D. Courtney P. D. Courtney Department of Crop Science, North Carolina State University, Raleigh, NC, 27695-7620 USA Search for more papers by this author J. Chen J. Chen Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, UT, 84112-5820 USA Search for more papers by this author G. D. Prestwich G. D. Prestwich Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, UT, 84112-5820 USA Search for more papers by this author A. B. Theibert A. B. Theibert Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author R. E. Dewey R. E. Dewey Department of Crop Science, North Carolina State University, Raleigh, NC, 27695-7620 USA Search for more papers by this author V. A. Bankaitis Corresponding Author V. A. Bankaitis Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA Search for more papers by this author Author Information M. A. Kearns1, D. E. Monks2, M. Fang1, M. P. Rivas1, P. D. Courtney2, J. Chen3, G. D. Prestwich3, A. B. Theibert4, R. E. Dewey2 and V. A. Bankaitis 1 1Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA 2Department of Crop Science, North Carolina State University, Raleigh, NC, 27695-7620 USA 3Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, UT, 84112-5820 USA 4Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35294-0005 USA *Corresponding author. E-mail: [email protected] The EMBO Journal (1998)17:4004-4017https://doi.org/10.1093/emboj/17.14.4004 PDFDownload PDF of article text and main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info Phosphatidylinositol transfer proteins (PITPs) have been shown to play important roles in regulating a number of signal transduction pathways that couple to vesicle trafficking reactions, phosphoinositide-driven receptor-mediated signaling cascades, and development. While yeast and metazoan PITPs have been analyzed in some detail, plant PITPs remain entirely uncharacterized. We report the identification and characterization of two soybean proteins, Ssh1p and Ssh2p, whose structural genes were recovered on the basis of their abilities to rescue the viability of PITP-deficient Saccharomyces cerevisiae strains. We demonstrate that, while both Ssh1p and Ssh2p share ∼25% primary sequence identity with yeast PITP, these proteins exhibit biochemical properties that diverge from those of the known PITPs. Ssh1p and Ssh2p represent high-affinity phosphoinositide binding proteins that are distinguished from each other both on the basis of their phospholipid binding specificities and by their substantially non-overlapping patterns of expression in the soybean plant. Finally, we show that Ssh1p is phosphorylated in response to various environmental stress conditions, including hyperosmotic stress. We suggest that Ssh1p may function as one component of a stress response pathway that serves to protect the adult plant from osmotic insult. Introduction Phosphatidylinositol/phosphatidylcholine transfer proteins (PITPs) transfer either phosphatidylinositol (PI) or phosphatidylcholine (PC) between membrane bilayers in vitro (Cleves et al., 1991a; Wirtz, 1991), and this class of proteins exhibits two hallmark features of interest. First, PITPs are unique in that while these polypeptides contain one phospholipid (PL) binding site per protein monomer, PITPs have the ability to accommodate binding of two dissimilar PLs (PI and PC) in a mutually exclusive binding reaction. Secondly, PITPs exhibit a high level of primary sequence conservation. These homologies among PITPs are presently bifurcated into two distinct branches. PITPs of mammalian and insect origin share at least 40% primary sequence identity (Dickeson et al., 1989; Vihtelic et al., 1993; Tanaka and Hosaka, 1994; Chang et al., 1997). Fungal PITPs are also highly similar to each other at the primary sequence level (Bankaitis et al., 1989, 1990; Salama et al., 1990; Lopez et al., 1994), but share no primary sequence similarity with metazoan PITPs (Bankaitis et al., 1989; Dickeson et al., 1989; Vihtelic et al., 1993). The Saccharomyces cerevisiae SEC14 gene product (Sec14p) represents the major PITP of yeast, and plays an essential role in protein exit from the yeast Golgi complex (Bankaitis et al., 1989, 1990). A dissection of how Sec14p translates its PI/PC-exchange activity to biological function has been driven by the characterization of mutations that relieve cells of the normally essential Sec14p requirement for Golgi function and cell viability (Cleves et al., 1989, 1991b; Alb et al., 1996; Fang et al., 1996). Characterization of these ‘bypass Sec14p’ mutations has generated the proposal that Sec14p maintains the integrity of a critical Golgi diacylglycerol (DAG) pool that is required for Golgi secretory function (McGee et al., 1994; Kearns et al., 1997). An important aspect of this function is the ability of the PC-bound form of Sec14p to repress the activity of the CDP-choline pathway for PC biosynthesis (a potent DAG consumer) in yeast Golgi membranes (McGee et al., 1994; Skinner et al., 1995). The PI-bound form of Sec14p may function independently in potentiating PI metabolism in an action which would resupply the Golgi DAG pool. This mode of action is inferred from the demonstration that accelerated PI-turnover represents one in vivo mechanism for effecting a ‘bypass Sec14p’ phenotype (Kagiwada et al., 1996; Kearns et al., 1997), that the PI-transfer activity of mammalian PITP is necessary for rescue of Sec14p defects (Alb et al., 1995), and that both Sec14p and mammalian PITPs stimulate PI-metabolism in phosphoinositide-dependent reactions that have been reconstituted in permeabilized mammalian cells (Hay and Martin, 1993; Thomas et al., 1993; Hay et al., 1995; Cunningham et al., 1996). Indeed, PITP function prevents the onset of specific neurodegenerative diseases in Drosophila and mammals, although the in vivo mechanisms of PITP action remain unclear (Hamilton et al., 1997; Milligan et al., 1997). While fungal and metazoan PITPs have been analyzed in some detail, plant PITPs remain uncharacterized. Herein, we report the identification and characterization of two novel soybean Sec14p homologs, designated Ssh1p and Ssh2p. These homologs share some 25% sequence identity with Sec14p, and expression of these proteins is developmentally regulated in the plant. The primary sequence homologies shared by these SSH proteins with Sec14p translate to some level of functional relatedness since high-level expression of either Ssh1p or Ssh2p is sufficient for rescue of the growth and Golgi secretory defects associated with haploid lethal sec14Δ mutations. While Ssh2p exhibits robust PI-transfer activity in vitro, Ssh1p exhibits no such activity. Moreover, neither Ssh1p nor Ssh2p are capable of effecting PC transfer in vitro. In fact, both Ssh1p and Ssh2p are high-affinity phosphoinositide binding proteins that exhibit distinct phospholipid binding specificities. As such, Ssh1p and Ssh2p represent new members of the Sec14p family of proteins that exhibit novel biochemical properties. Finally, we report that Ssh1p is rapidly phosphorylated in response to the exposure of cells to a variety of environmental stresses (e.g. hyperosmotic stress) and that the phosphorylated form of Ssh1p fails to associate with membranes. The distinct biochemical properties of Ssh1p and Ssh2p, when coupled with their differentially regulated patterns of expression in the plant, suggest that Ssh1p and Ssh2p play distinct physiological roles. Ssh1p, in particular, may play a role in regulating the response of soybean plants to environments of high osmolarity. Results Identification of two functional homologs of yeast Sec14p from a higher plant Functional rescue of yeast Sec14p defects represents a simple method for recovering genes encoding heterologous PITPs (Skinner et al., 1993; Tanaka and Hosaka, 1994). To isolate higher plant PITP genes, we constructed a developing soybean seed cDNA library that was engineered for high-level expression in yeast (see Materials and methods). Fifteen cDNA clones, representing two distinct cDNA species designated SSH1 and SSH2, were recovered by virtue of their ability to rescue the growth defects of a sec14-1ts strain at 37°C (Figure 1A). Importantly, plasmid shuffle experiments (see Lopez et al., 1994) demonstrated that SSH1 and SSH2 expression also remedied the unconditional lethality associated with sec14Δ alleles (Figure 1A). Thus, the SSH1 and SSH2 gene products were able to substitute for Sec14p when expressed in yeast. However, this functional substitution required high-level expression of Ssh1p or Ssh2p, as evidenced by our finding that the introduction of centromeric plasmids bearing PPGK::SSH1 or PPGK::SSH2 cassettes was insufficient to support rescue of either sec14Δ or sec14-1ts alleles (e.g. strains CTY1013 and CTY1015; see Table I). Moreover, Ssh2p expression consistently yielded a superior improvement in growth of Sec14p-deficient strains relative to Ssh1p expression (Figure 1A). Figure 1.(A) Expression of soybean SSH1 and SSH2 genes rescues the growth defects of Δsec14 yeast and sec14-1ts strains. Growth properties of a wild-type yeast strain (CTY182), its isogenic sec14-1ts derivative (CTY1-1A), and various sec14 derivative strains carrying either YEp(SSH1) or YEp(SSH2) plasmids are shown. The sec14ts strains (CTY937 and CTY938) all represent strain CTY1-1A carrying the indicated plasmid, while the Δsec14 strains (CTY897 and CTY898) were generated by plasmid shuffle exactly as described by Lopez et al. (1994). These yeast strains were streaked onto YPD plates and incubated for 36 h at the indicated temperatures. High-level expression of either SSH1 or SSH2 not only restored growth of sec14-1ts strains at the normally restrictive temperature at 37°C, but also restored viability at all temperatures to yeast strains carrying the haploid-lethal Δsec14 allele. Thus, when expressed at high levels, Ssh1p and Ssh2p are individually able to fulfill in yeast the essential cellular functions of Sec14p. (B) Efficiency of invertase secretion at 37°C for Δsec14 strains carrying the indicated YEp(SSH) plasmids. The secretion index relates extracellular secreted invertase to total cellular invertase as described (Salama et al., 1990). The secretion indices of wild-type and sec14-1ts strains represent measures of normal secretory proficiency and the magnitude of the sec14-1ts Golgi secretory block, respectively. The Δsec14 strains CTY897 and CTY898 (see Table I) were analyzed for secretory competence to determine the efficiency with which SSH1 and SSH2 expression rescued Δsec14-associated secretory defects, respectively. These data indicate that Ssh1p and Ssh2p expression in yeast significantly alleviated the Golgi secretory defect associated with complete loss of Sec14p function. (C) Ssh1p and Ssh2p share primary sequence homology with fungal PITPs. An alignment of the entire Sec14p, Ssh1p, and Ssh2p primary sequences is shown, and corresponding residue numbers are designated at the far right of each column. These soybean polypeptides each share ∼25% primary sequence identity (and 50% similarity) with Sec14p. Composite identities are indicated by the residues boxed in black, while the Sec14p residues within the white boxes represent amino acid residues conserved in four of the fungal Sec14ps (i.e. Saccharomyces cerevisiae, Kluyveromyces lactis, Yarrowia lipolytica and Schizosaccharomyces pombe) we have characterized to date. Download figure Download PowerPoint Table 1. Yeast strains CTY-1A MATa, ura3-52, Δhis3-200, lys2-801am, sec14-1ts CTY809 MATa, ura3-52, Δhis3-200, lys2-801am, sec14-1ts/YEp lac195 CTY182 MATa, ura3-52, Δhis3-200, lys2-801am CTY807 MATa, ura3-52, Δhis3-200, lys2-801am/YEp lac195 CTY303 MATa, ura3-52, Δhis3-200, cki, sec14ΔP::hisG CTY808 MATa, ura3-52, Δhis3-200, cki, sec14ΔP::hisG/YEp lac195 CTY897 MATa, ade2, ade3, ura3-52, Δhis3-200, leu2, sec14ΔP::hisG/YEp(SSH1, URA3) CTY898 MATa, ade2, ade3, ura3-52, Δhis3-200, leu2, sec14ΔP::hisG/YEp(SSH2, URA3) CTY899 MATa, ura3-52, Δhis3-200, cki, sec14ΔP::hisG/YEp(SSH1) CTY900 MATa, ura3-52, Δhis3-200, cki, sec14ΔP::hisG/YEp(SSH2) CTY920 MATa, ura3-52, Δhis3-200, cki, sec14ΔP::hisG/YEp(SSH1HIS6) CTY937 MATa, ura3-52, Δhis3-200, lys2-801am, sec14-1ts/YEp(SSH1) CTY938 MATa, ura3-52, Δhis3-200, lys2-801am, sec14-1ts/YEp(SSH2) CTY940 MATa, ura3-52, Δhis3-200, cki, sec14ΔP::hisG/YEp(SSH2myc) CTY1013 MATa, ura3-52, Δhis3-200, lys2-801am, sec14-1ts/YCp(PPGK::SSH1) CTY1015 MATa, ura3-52, Δhis3-200, lys2-801am, sec14-1ts/YCp(PPGK::SSH2) SSH1 or SSH2 expression alleviated sec14 growth defects and elicited significant relief of the secretory block associated with Sec14p insufficiencies. As shown in Figure 1B, wild-type strains grown at 37°C exhibited a secretion index (90.9 ± 0.4%) that indicated efficient trafficking of invertase through the secretory pathway to the cell surface. In contrast, an isogenic sec14-1ts strain exhibited a secretion index of only 28.2 ± 2.4%. This value was diagnostic of the accumulation of a major intracellular pool of invertase that is blocked in transit from the yeast Golgi complex (Bankaitis et al., 1989; Franzusoff and Schekman, 1989; Cleves et al., 1991b). However, expression of SSH1 and SSH2 elevated the secretion index of a sec14 null strain grown at 37°C to 55.8 ± 6.2% and 80.2 ± 1.8%, respectively, i.e. values substantially greater than those determined for the sec14-1ts strain at the restrictive temperature (Figure 1B). Again, in accordance with the growth phenotypes described above, Ssh2p expression elicited a reproducibly more efficient rescue of Sec14p-related Golgi secretory defects than did Ssh1p expression. Ssh1p and Ssh2p share primary sequence homology with fungal Sec14ps The nucleotide sequences of the SSH1 and SSH2 cDNAs were determined and found to encode respective open reading frames of 975 and 771 bp, respectively. These sequences have been registered with the DDBJ/EMBL/GenBank database with the following accession numbers: AF024651 (SSH1) and AF024652 (SSH2). SSH1 and SSH2 are inferred to encode proteins of 324 and 256 amino acid residues, respectively, with corresponding molecular masses of 36.9 and 29 kDa. Immunodetection of Ssh1p and Ssh2p, both from producing yeast strains and from soybean sources, provided data in excellent agreement with these expectations (see below). As shown in Figure 1C, Ssh1p and Ssh2p share ∼25% primary sequence identity and 50% similarity with each other, and with Sec14p. The alignments in Figure 1C indicate that the shared primary sequence motifs correspond to motifs that are highly conserved in all characterized fungal Sec14ps, including those from the budding yeast Kluyveromyces lactis (Salama et al., 1990), the dimorphic yeast Yarrowia lipolytica (Lopez et al., 1994), and the fission yeast Schizosaccharomyces pombe (H.B.Skinner and V.A. Bankaitis, unpublished data). In particular, the signature motifs LLRFLRARKF, DGRPVY, YYPERMGKFY and INAP of fungal Sec14ps were all clearly recognizable in the inferred Ssh1p and Ssh2p primary sequences (Figure 1C). No cDNAs from germinating soybean seed that encode proteins exhibiting primary sequence relatedness with mammalian PITPs were obtained in this functional screen. Expression of SSH genes is developmentally regulated in soybean The high frequency of recovery for SSH2 cDNA clones, relative to SSH1 cDNA clones, in our functional screen suggested the possibility that SSH2 was more highly expressed in developing seeds than was SSH1. Northern blot analyses indicated that such was indeed the case. The steady-state abundance of SSH1 transcripts was greatest in leaf and root tissue, and was of only low abundance in developing seeds (Figure 2). In contrast, SSH2 transcripts were most abundant in developing seeds. Only low levels of SSH2 poly(A)+-RNA were detected in leaf tissue and we were unable to detect SSH2 expression in roots (Figure 2). Immunoblotting experiments with the corresponding tissue extracts were entirely consistent with the Ssh1p and Ssh2p expression pattern as deduced from the Northern blot analysis (not shown). Finally, Southern blot analyses, where soybean genomic DNA was individually probed with SSH1 or SSH2 cDNA, revealed a rather simple banding pattern. While the intron/exon organization and pseudogene repertoire for each SSH gene remains undetermined, the banding complexity obtained is consistent with each SSH gene being either unique, or belonging to a small multigene family (Figure 2). Figure 2.Expression of SSH1 and SSH2 is developmentally regulated in the soybean plant. Total genomic DNA from young soybean leaves was isolated as described (Murray and Thompson, 1980). Genomic DNA (10 μg) was restricted with the indicated restriction enzymes, resolved by electrophoresis on 1% agarose gels, and hybridized to radiolabeled SSH1 and SSH2 probes. The restriction enzymes employed do not cleave the corresponding SSH cDNAs. Molecular length markers are presented at the left in kilobase units. Northern (mRNA) blot assays were conducted using 10 μg of poly(A)+ RNA recovered from the specified tissues. The molecular lengths of the hybridizing transcripts were estimated using RNA size standards (not shown). Download figure Download PowerPoint Ssh1p and Ssh2p are not typical PITPs High-level expression of mammalian PITP in yeast is sufficient to rescue the growth and secretory defects associated with sec14-1ts defects (Skinner et al., 1993). The rescue of sec14 defects associated with expression of Ssh1p or Ssh2p in yeast, when coupled with the primary sequence relatedness of Ssh1p and Ssh2p to Sec14p (Figure 1C), suggested that Ssh1p and Ssh2p represented soybean PITPs. As a qualitative test of this possibility, we individually expressed Ssh1p and Ssh2p in the cki, sec14Δ yeast strain CTY303 (Table I) and measured the ability of cytosol prepared from these strains to effect PI and PC transfer in vitro. CTY303 was employed for these studies because it is devoid of endogenous PI- or PC-transfer activity as a consequence of the sec14Δ lesion. This strain retains full viability, in spite of the haploid-lethal nature of sec14Δ, because of the ‘bypass Sec14p’ property of the cki lesion which inactivates choline kinase, the first enzyme of the CDP–choline pathway for PC biosynthesis (Cleves et al., 1991b; Skinner et al., 1993). In these experiments, cytosol represented a clarified salt-stripped fraction of broken cell lysate (see Materials and methods). Salt-stripping was performed because significant fractions of both Ssh1p and Ssh2p were membrane associated (see below). Analysis of the phospholipid transfer properties of Ssh1p and Ssh2p cytosol, prepared from CTY303, yielded unanticipated results, and data are shown in Figure 3A and B. As positive control, the phospholipid transfer activities of wild-type yeast (Sec14p) cytosol were individually measured, and robust PI- and PC- transfer activities were recorded. Both transfer activities were linear in the range of 0 to at least 2 mg added cytosol, and 2 mg wild-type yeast cytosol effected ∼8 and 16% of total input radiolabeled PI- and PC-substrate, respectively, under the employed experimental conditions. Ssh2p cytosol also exhibited robust PI-transfer activity. Indeed, the PI-transfer activity of Ssh2p cytosol was in excess of that measured for Sec14p cytosol, which resulted from Ssh2p expression being driven by a powerful promoter from an expression cassette carried by a multicopy plasmid. Immunoblotting data were consistent with Ssh2p levels in cytosol preparations markedly exceeding those recorded for Sec14p in wild-type yeast cytosol (not shown). Yet, PC-transfer activity was essentially undetectable in Ssh2p cytosol (Figure 3A and B). The demonstration that Ssh2p cytosol effected efficient PI-transfer indicated that our inability to measure PC-transfer was neither the trivial result of inefficient recovery of Ssh2p, nor the result of catastrophic degradation of Ssh2p during cytosol preparation. Characterization of Ssh1p cytosol also provided unanticipated results as it failed to support significant PI- or PC-transfer activity, even at high concentrations (Figure 3A and B). The stability of Ssh1p during the cytosol preparation was not a contributory factor to our inability to record PI- and PC-transfer activity since high levels of full-length Ssh1p were detected by immunoblotting of input cytosol (not shown). Figure 3.Phospholipid transfer activities of cytosol prepared from Ssh1p- and Ssh2p-expressing strains of yeast. A wild-type yeast strain carrying a YEpURA3 plasmid (CTY807), and strains CTY808, Δsec14cki/YEp(URA3); CTY899, Δsec14cki/YEp(PADH::SSH1); and CTY900 Δsec14cki/YEp(PADH::SSH2) were grown in minimal media lacking uracil to mid-logarithmic phase and cells harvested by centrifugation. Cytosol was prepared by adjustment of cell-free extracts to a final concentration of 500 mM KCl and collection of the 100 000 g supernatant fraction (see Materials and methods). The protein concentrations of the resulting cytosolic fractions were determined and the samples were assayed for PI- and PC-transfer activity as described elsewhere (Aitken et al., 1990). PI- and PC-transfer data are shown separately in (A) and (B), respectively. Activity is expressed as the percent of total radiolabeled PI or PC in the assay that was transferred during the course of the experiment after subtraction of background. The background was represented by the transfer values acheived with the PI-/PC-transfer protein deficient cytosol prepared from strain CTY808. Values recorded for the wild-type yeast strain CTY807 (closed circles; designated WT) measure the Sec14p activity normally present in yeast cytosol and serve as positive controls. Values recorded for Ssh1p cytosol (CTY899) and Ssh2p cytosol (CTY900) are represented by stippled squares [YEp(SSH1)] and open circles [YEp(SSH2)], respectively. Data represent the averages of at least three independent experiments. (C) Phospholipid transfer properties of purified Ssh1p and Ssh2p. Recombinant His6-tagged Ssh1p, Ssh2p and Sec14p were purified from E.coli and assayed for PI- and PC-transfer activity as described in the Materials and methods. The efficiency of phospholipid transfer for each Sec14p assay was set at 100% transfer, and the transfer activities of Ssh1p and Ssh2p were compared accordingly. In these assays, recombinant proteins were added at amounts that sustained transfer activity in the linear range with respect to protein concentration, and these amounts are indicated at the bottom. Data represent the averages of at least three independent experiments. Note that >5 μg of Sec14p saturated the PI- and PC-transfer assays, whereas 10-fold greater amounts of recombinant Ssh2p were required to generate comparable PI-transfer activity. Even large amounts of purified recombinant Ssh1p (200 μg) failed to yield measurable PI- or PC-transfer activity. Assay of 200 μg of Ssh2p also failed to generate significant PC-transfer activity. For transfer assays, total input [3H]phosphatidylinositol and [14C]phosphatidycholine equalled ∼7000 and 27 000 c.p.m. per assay, respectively. Background for PI- and PC-transfer assays ranged between 100–198 and 643–800 c.p.m. per transfer reaction, respectively. Download figure Download PowerPoint The yeast cytosol data suggested that neither Ssh1p nor Ssh2p represented typical PITPs, i.e. proteins that exhibit both PI- and PC-transfer activity. To effect a more quantitative comparison of the phospholipid transfer activities of these Sec14p homologs, we expressed His6-tagged Ssh1p and Ssh2p in E.coli. The phospholipid transfer properties of the purified proteins were then determined. As illustrated in Figure 3C, the data obtained with Ssh1p and Ssh2p purified from E.coli broadly recapitulated the results generated with the corresponding yeast cytosol preparations. Ssh1p was inactive with respect to PI- or PC-transfer activity, even when 200 μg of purified protein were assayed. Yet, we believe that the relevant functional properties of Ssh1p are retained in the recombinant protein (see below). Recombinant Ssh2p scored as an active PI-transfer protein (Figure 3C), but was substantially weaker than Sec14p in activity. From titration experiments, we estimate His6-Sec14p purified from E.coli exhibited ∼10-fold greater specific activity for PI-transfer than did His6-Ssh2p recovered from the same source. As expected, in marked contrast to the robust PC-transfer activity elaborated by His6-Sec14p, purified His6-Ssh2p was inactive for PC transfer (Figure 3C), even at 200 μg Ssh2p per PC-transfer assay (not shown). The collective data indicate Ssh1p and Ssh2p exhibit biochemical properties that diverge from those associated with all other presently known PITPs that are characterized by their abilities to effect both PI and PC transfer. Ssh1p is devoid of both PI- and PC-transfer activity, whereas Ssh2p is a novel PI-transfer protein that elaborates PI-transfer activity in the absence of accompanying PC-transfer activity. Ssh1p and Ssh2p are novel phosphoinositide binding proteins We had previously demonstrated that the PI-transfer activity of mammalian PITP was required for expression of this protein to effect a heterologous rescue of Sec14p growth and secretory defects in yeast (Alb et al., 1995). Since mammalian PITP stimulates phosphatidylinositol-4,5-bisphosphate (PIP2) synthesis in permeabilized cells (Cunningham et al., 1995; Hay et al., 1995), we used a photoaffinity radiolabeling strategy to ascertain whether Ssh1p and Ssh2p represented phosphoinositide binding proteins. Specifically, we employed [3H]triester-BZDC-PI(4,5)P2 {[([3H](p-benzoyldihydrocinnamidyl)-amino) propyl]-phosphatidylinositol-4,5-bisphosphate} and [3H]triesterBZDC-InsP3 {[([3H](p-benzoyldihydrocinnamidyl)-amino) propyl]-inositol-1,4,5-trisphosphate} as photo- affinity ligands (Dorman and Prestwich, 1994; Prestwich, 1996; Prestwich et al., 1997, 1998). Both ligands had previously been shown to exhibit highly selective IP3 and PIP2-displaceable photocovalent modification of the pleckstrin homology domain of phospholipase Cδ1 (Tall et al., 1997), and [3H]triester-BZDC photoprobes were successfully employed to characterize the phosphoinositide binding specificity of the mammalian Golgi coatomer complex (Chaudhary et al., 1998). Neither His6-Ssh1p nor His6-Ssh2p were efficiently photolabeled by the PIP2 headgroup photoprobe [3H]BZDC-IP3, even though the control PIP2 binding protein, gelsolin, exhibited intense photolabeling that was competed by excess unlabeled PIP2 (not shown). However, both His6-Ssh1p and His6-Ssh2p were successfully labeled by the [3H]BZDC-PIP2 ligand, and binding of this phosphotriester photoprobe was competed by challenge with excess unlabeled PIP2 (Figure 4A). As expected, the known PIP2 binding protein gelsolin also exh DA - 1998/7/15/ PY - 1998/7/15/ DO - 10.1093/emboj/17.14.4004 VL - 17 IS - 14 SP - 4004-4017 SN - 0261-4189 KW - phosphatidylinositol transfer proteins KW - phosphoinositides KW - signaling KW - soybean KW - stress response ER - TY - JOUR TI - Multiple cis elements contribute to geminivirus origin function AU - Orozco, BM AU - Gladfelter, HJ AU - Settlage, SB AU - Eagle, PA AU - Gentry, RN AU - Hanley-Bowdoin, L T2 - VIROLOGY AB - The genome of the geminivirus tomato golden mosaic virus (TGMV) consists of two circular DNA molecules which are dissimilar in sequence except for a highly conserved 200-bp common region that includes the origin for rolling circle replication. To better characterize the plus-strand origin, we analyzed the capacities of various TGMV common region sequences to support episomal replication in tobacco protoplasts when the viral replication proteins AL1 and AL3 were supplied in trans. These experiments demonstrated that the minimal origin is located in 89-bp common region fragment that includes the known AL1 binding motif and a hairpin structure containing the DNA cleavage site. Analyses of mutant origin sequences identified two additional cis elements--one that is required for origin activity and a second that greatly enhances replication. In contrast, a conserved partial copy of the AL1 binding site did not contribute to origin function. Mutational analysis of the functional AL1 binding site showed that both spacing and sequence of this motif are important for replication in vivo and AL1/DNA binding in vitro. Spacing changes between the AL1 binding site and hairpin also negatively impacted TGMV origin function in a position-dependent manner. Together, these results demonstrated that the organization of TGMV plus-strand origin is complex, involving multiple cis elements that are likely to interact with each other during initiation of replication. DA - 1998/3/15/ PY - 1998/3/15/ DO - 10.1006/viro.1997.9013 VL - 242 IS - 2 SP - 346-356 SN - 0042-6822 ER - TY - JOUR TI - First report of Plasmodiophora brassicae on cabbage in eastern North Carolina. AU - Cubeta, MA AU - Cody, BR AU - Williams, PH T2 - PLANT DISEASE AB - Clubroot, caused by Plasmodiophora brassicae Woronin, has occurred for at least 50 years in three counties in northwestern North Carolina, but has not been reported previously from eastern North Carolina, where most commercial cabbage is produced. In the fall of 1995, clubroot was observed in a direct seeded, commercial cabbage field in Plymouth, NC. Diseased cabbage plants were stunted and roots exhibited clublike swellings. Clubs were randomly harvested from roots of five plants to obtain a composite isolate to determine which race(s) of P. brassicae are infecting cabbage in eastern North Carolina. Three experiments were conducted, using the procedure of Williams (2). Four replicates of 10, 1-week-old seedlings of eight different crucifer cultivars were inoculated by dipping in a spore suspension (1 × 10 8 cysts/ml) of P. brassicae and planted in pasteurized potting mix. Seedlings dipped in sterile water served as controls. Inoculated seedlings were incubated in a greenhouse at 18 to 28°C for 6 to 8 weeks and assessed for clubroot incidence and severity. The isolate of P. brassicae from eastern North Carolina was most virulent on cabbage (Brassica oleracea var. capitata cv. Jersey Queen), collard (B. oleracea var. acephala cv. Vates), and wild mustard (B. nigra); moderately virulent on canola (B. napus cv. Brutor) and rutabaga (B. napus cvs. Laurentian and Wilhelmsburger); and least virulent on cabbage (cv. Badger Shipper). Canola (B. napus cv. Nevin) and control seedlings were not infected and exhibited no symptoms. Similar results were obtained for all experiments. Based on these results, the isolate of P. brassicae from eastern North Carolina was designated as race 6 and pathotype 5 according to Williams (2) and Some (1), respectively. However, further experiments with single-cyst-derived isolates from individual clubs obtained from different geographic locations are needed to accurately characterize field populations of P. brassicae on cabbage in eastern North Carolina. References: (1) A. Some et al. Plant Pathol. 45:432, 1996. (2) P. H. Williams. Phytopathology 56:624, 1966. DA - 1998/1// PY - 1998/1// DO - 10.1094/PDIS.1998.82.1.129D VL - 82 IS - 1 SP - 129-129 SN - 1943-7692 ER - TY - JOUR TI - Biooxidation capacity of the extremely thermoacidophilic archaeon Metallosphaera sedula under bioenergetic challenge AU - Han, CJ AU - Kelly, RM T2 - BIOTECHNOLOGY AND BIOENGINEERING AB - The biooxidation capacity of an extremely thermoacidophilic archaeon Metallosphaera sedula (DSMZ 5348) was examined under bioenergetic challenges imparted by thermal or chemical stress in regard to its potential use in microbial bioleaching processes. Within the normal growth temperature range of M. sedula (70–79°C) at pH 2.0, upward temperature shifts resulted in bioleaching rates that followed an Arrhenius-like dependence. When the cells were subjected to supraoptimal temperatures through gradual thermal acclimation at 81°C (Han et al., 1997), cell densities were reduced but 3 to 5 times faster specific leaching rates (Fe3+ released from iron pyrite/cell/h) could be achieved by the stressed cells compared to cells at 79°C and 73°C, respectively. The respiration capacity of M. sedula growing at 74°C was challenged by poisoning the cells with uncouplers to generate chemical stress. When the protonophore 2,4-dinitrophenol (5–10 μM) was added to a growing culture of M. sedula on iron pyrite, there was little effect on specific leaching rates compared to a culture with no protonophore at 74°C; 25 μM levels proved to be toxic to M. sedula. However, a significant stimulation in specific rate was observed when the cells were subjected to 1 μM nigericin (+135%) and 2 μM (+63%); 5 μM levels of the ionophore completely arrested cell growth. The ionophore effect was further investigated in continuous culture growing on ferrous sulfate at 74°C. When 1 μM nigericin was added as a pulse to a continuous culture, a 30% increase in specific iron oxidation rate was observed for short intervals, indicating a potential positive impact on leaching when periodic chemical stress is applied. This study suggests that biooxidation rates can be increased by strategic exposure of extreme thermoacidophiles to chemical or thermal stress, and this approach should be considered for improving process performance. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58: 617–624, 1998. DA - 1998/6/20/ PY - 1998/6/20/ DO - 10.1002/(SICI)1097-0290(19980620)58:6<617::AID-BIT7>3.0.CO;2-L VL - 58 IS - 6 SP - 617-624 SN - 0006-3592 KW - thermoacidophile KW - chemolithotroph KW - heat shock KW - chemical stress KW - continuous culture ER - TY - JOUR TI - Assessing the impact of secondary structure and solvent accessibility on protein evolution AU - Goldman, N. AU - Thorne, J. L. AU - Jones, D. T. T2 - Genetics DA - 1998/// PY - 1998/// VL - 149 IS - 1 SP - 445-458 ER - TY - JOUR TI - A family of Drosophila genes encoding quaking-related maxi-KH domains AU - Fyrberg, C AU - Becker, J AU - Barthmaier, P AU - Mahaffey, J AU - Fyrberg, E T2 - BIOCHEMICAL GENETICS DA - 1998/2// PY - 1998/2// DO - 10.1023/A:1018700202971 VL - 36 IS - 1-2 SP - 51-64 SN - 0006-2928 KW - Drosophila genetics KW - K homology domains KW - STAR proteins KW - nucleic acid-binding motifs ER - TY - JOUR TI - Three slicing cucumber populations: NCWBS, NCMBS, and NCES1 AU - Wehner, T. C. T2 - HortScience DA - 1998/// PY - 1998/// VL - 33 IS - 1 SP - 168-170 ER - TY - JOUR TI - Phenological variation in height and diameter growth in provenances and families of loblolly pine AU - Jayawickrama, KJS AU - McKeand, SE AU - Jett, JB T2 - NEW FORESTS DA - 1998/7// PY - 1998/7// DO - 10.1023/A:1016527317326 VL - 16 IS - 1 SP - 11-25 SN - 1573-5095 KW - shoot phenology KW - shoot growth KW - diameter growth KW - growth cessation KW - Pinus taeda ER - TY - JOUR TI - A phosphatidylinositol 4-kinase pleckstrin homology domain that binds phosphatidylinositol 4-monophosphate AU - Stevenson, JM AU - Perera, IY AU - Boss, WF T2 - JOURNAL OF BIOLOGICAL CHEMISTRY AB - Pleckstrin homology (PH) domains are found in many proteins involved in signal transduction, including the family of large molecular mass phosphatidylinositol (PI) 4-kinases. Although the exact function of these newly discovered domains is unknown, it is recognized that they may influence enzyme regulation by binding different ligands. In this study, the recombinant PI 4-kinase PH domain was explored for its ability to bind to different phospholipids. First, we isolated partial cDNAs of the >7-kilobase transcripts of PI 4-kinases from carrot (DcPI4Kα) andArabidopsis (AtPI4Kα). The deduced primary sequences were 41% identical and 68% similar to rat and human PI 4-kinases and contained the telltale lipid kinase unique domain, PH domain, and catalytic domain. Antibodies raised against the expressed lipid kinase unique, PH, and catalytic domains identified a polypeptide of 205 kDa in Arabidopsis microsomes and an F-actin-enriched fraction from carrot cells. The 205-kDa immunoaffinity-purified Arabidopsis protein had PI 4-kinase activity. We have used the expressed PH domain to characterize lipid binding properties. The recombinant PH domain selectively bound to phosphatidylinositol 4-monophosphate (PI-4-P), phosphatidylinositol 4,5-bisphosphate (PI-4,5-P2), and phosphatidic acid and did not bind to the 3-phosphoinositides. The PH domain had the highest affinity for PI-4-P, the product of the reaction. Consideration is given to the potential impact that this has on cytoskeletal organization and the PI signaling pathway in cells that have a high PI-4-P/PI-4,5-P2 ratio. Pleckstrin homology (PH) domains are found in many proteins involved in signal transduction, including the family of large molecular mass phosphatidylinositol (PI) 4-kinases. Although the exact function of these newly discovered domains is unknown, it is recognized that they may influence enzyme regulation by binding different ligands. In this study, the recombinant PI 4-kinase PH domain was explored for its ability to bind to different phospholipids. First, we isolated partial cDNAs of the >7-kilobase transcripts of PI 4-kinases from carrot (DcPI4Kα) andArabidopsis (AtPI4Kα). The deduced primary sequences were 41% identical and 68% similar to rat and human PI 4-kinases and contained the telltale lipid kinase unique domain, PH domain, and catalytic domain. Antibodies raised against the expressed lipid kinase unique, PH, and catalytic domains identified a polypeptide of 205 kDa in Arabidopsis microsomes and an F-actin-enriched fraction from carrot cells. The 205-kDa immunoaffinity-purified Arabidopsis protein had PI 4-kinase activity. We have used the expressed PH domain to characterize lipid binding properties. The recombinant PH domain selectively bound to phosphatidylinositol 4-monophosphate (PI-4-P), phosphatidylinositol 4,5-bisphosphate (PI-4,5-P2), and phosphatidic acid and did not bind to the 3-phosphoinositides. The PH domain had the highest affinity for PI-4-P, the product of the reaction. Consideration is given to the potential impact that this has on cytoskeletal organization and the PI signaling pathway in cells that have a high PI-4-P/PI-4,5-P2 ratio. Since the first report of changes in phosphoinositide metabolism in response to light (1Morse M.J. Crain R.C. Satter R.L. Proc. Natl. Acad. Sci. U. S. A. 1987; 84: 7075-7078Crossref PubMed Google Scholar), there have been many studies of the metabolism of inositol phospholipids in plants (2Drøbak B.K. Biochem. J. 1992; 288: 697-712Crossref PubMed Scopus (145) Google Scholar, 3Cote G.G. Crain R.C. Bioessays. 1994; 16: 39-46Crossref Scopus (46) Google Scholar, 4Perera I.Y. Boss W.F. Briggs W.R. Heath R.L. Tobin E.M. Regulation of Plant Growth and Development by Light. American Society of Plant Physiologists, Rockville, MD1996: 114-126Google Scholar). These studies reveal two distinguishing features of phosphoinositide metabolism in higher plants: 1) [3H]PI-4-P 1The abbreviations used are: PI-4-Pphosphatidylinositol 4-monophosphatePI-45-P2, phosphatidylinositol 4,5-bisphosphatePI4Kphosphatidylinositol 4-kinasePIphosphatidylinositolPH domainpleckstrin homology domainPLCphospholipase CPI-3-Pphosphatidylinositol 3-monophosphatePI-34-P2, phosphatidylinositol 3,4-bisphosphatePAphosphatidic acidPCRpolymerase chain reaction, RACE, rapid amplification of cDNA endskbkilobaseseEF-1αelongation factor-1αPAGEpolyacrylamide gel electrophoresisNBD12-(N-methyl-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)). is 10–20-fold higher than [3H]PI-4,5-P2, and 2) changes in [3H]PI-4-P are detectable. Conversely, in the most responsive animal systems, the ratio of PI-4-P to PI-4,5-P2 is ∼1:1, and there is only a transient change in PI-4,5-P2, with little to no change in PI-4-P even though inositol 1,4,5-trisphosphate may increase 40-fold (5Cunningham E. Thomas G.M.H. Ball A. Hiles I. Cockcroft S. Curr. Biol. 1995; 5: 775-783Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar). One explanation that we are exploring for these differences is that the synthesis of PI-4,5-P2 is rate-limiting in plant cells because PI-4-P is sequestered by cytoskeletal or other proteins and not readily available for phosphorylation to PI-4,5-P2 or other metabolic pathways. phosphatidylinositol 4-monophosphate 5-P2, phosphatidylinositol 4,5-bisphosphate phosphatidylinositol 4-kinase phosphatidylinositol pleckstrin homology domain phospholipase C phosphatidylinositol 3-monophosphate 4-P2, phosphatidylinositol 3,4-bisphosphate phosphatidic acid polymerase chain reaction, RACE, rapid amplification of cDNA ends kilobases elongation factor-1α polyacrylamide gel electrophoresis 12-(N-methyl-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)). The first committed step in the biosynthesis of PI-4,5-P2is the phosphorylation of PI by PI 4-kinase to form PI-4-P. PI-4-P is phosphorylated by PI-4-P 5-kinase to form PI-4,5-P2. Biochemically, PI 4-kinase and PI-4-P 5-kinase activities have been studied in plant membranes (6Sommarin M. Sandelius A.S. Biochim. Biophys. Acta. 1988; 958: 268-278Crossref Scopus (82) Google Scholar, 7Sandelius A.S. Sommarin M. Morré D.J. Boss W.F. Loewus F.A. Inositol Metabolism in Plants. Wiley-Liss, New York1990: 139-161Google Scholar, 8Gross W. Yang W. Boss W.F. Biochim. Biophys. Acta. 1992; 1134: 73-80Crossref PubMed Scopus (17) Google Scholar, 9Cho M.H. Shears S.B. Boss W.F. Plant Physiol. ( Bethesda ). 1993; 103: 637-647Crossref PubMed Scopus (52) Google Scholar) and cytoskeletal (10Tan Z. Boss W.F. Plant Physiol. ( Bethesda ). 1992; 100: 2116-2120Crossref PubMed Scopus (73) Google Scholar, 11Xu P. Lloyd C.W. Staiger C.J. Drøbak B.K. Plant Cell. 1992; 4: 941-951Crossref PubMed Google Scholar) and soluble (12Okpodu C.M. Gross W. Burkhart W. Boss W.F. Plant Physiol. ( Bethesda ). 1995; 107: 491-500Crossref PubMed Scopus (18) Google Scholar) fractions. Recently, a putative PI-4-P 5-kinase was cloned fromArabidopsis (13Satterlee J.S. Sussman M.R. Plant Physiol. ( Bethesda ). 1997; 115: 864Google Scholar), but the genes encoding PI 4-kinases in plants have remained elusive. A clear distinction between two structurally different isoforms of the PI 4-kinase has emerged from the cloning and sequencing of PI 4-kinase from yeast (14Flanagan C.A. Schnieders E.A. Emerick A.W. Kunisawa R. Admon A. Thorner J. Science. 1993; 262: 1444-1448Crossref PubMed Scopus (174) Google Scholar, 15Garcia-Bustos J.F. Marini F. Stevenson I. Frei C. Hall M.N. EMBO J. 1994; 13: 2352-2361Crossref PubMed Scopus (103) Google Scholar, 16Yoshida S. Ohya Y. Goebl M. Nakano A. Anraku Y. J. Biol. Chem. 1994; 269: 1166-1171Abstract Full Text PDF PubMed Google Scholar), human (17Wong K. Cantley L.C. J. Biol. 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Chem. 1997; 272: 13236-13241Abstract Full Text Full Text PDF PubMed Scopus (161) Google Scholar). The second type encodes a larger protein of ∼200–230 kDa that is membrane-associated (19Nakagawa T. Goto K. Kondo H. J. Biol. Chem. 1996; 271: 12088-12094Abstract Full Text Full Text PDF PubMed Scopus (96) Google Scholar, 22Wong K. Meyers R. Cantley L.C. J. Biol. Chem. 1997; 272: 13236-13241Abstract Full Text Full Text PDF PubMed Scopus (161) Google Scholar). A distinctive feature of the group of higher molecular mass PI 4-kinases is that they contain putative PH domains. PH domains are poorly conserved protein modules of ∼100 amino acids in length (23Shaw G. Bioessays. 1996; 18: 35-46Crossref PubMed Scopus (256) Google Scholar, 24Lemmon M.A. Ferguson K.M. Schlessinger J. Cell. 1996; 85: 621-624Abstract Full Text Full Text PDF PubMed Scopus (433) Google Scholar, 25Ingley E. Hemmings B.A. J. Cell. Biochem. 1994; 56: 436-443Crossref PubMed Scopus (67) Google Scholar, 26Musacchio A. Gibson T. Rice P. Thompson J. Saraste M. Trends Biochem. Sci. 1993; 18: 343-348Abstract Full Text PDF PubMed Scopus (496) Google Scholar). These motifs exist in proteins that associate with membranes during signal transduction. PH domains bind a variety of ligands ranging from other signal transduction proteins such as G-protein βγ subunits (27Touhara K. Inglese J. Pitcher J.A. Shaw G. Lefkowitz R.J. J. Biol. Chem. 1994; 269: 10217-10220Abstract Full Text PDF PubMed Google Scholar) to polyphosphorylated inositol lipids (28Lomasney J.W. Cheng H.-F. Wang L.-P. Liu S.-M. Fesik S.W. King K. J. Biol. Chem. 1996; 271: 25316-25326Abstract Full Text Full Text PDF PubMed Scopus (107) Google Scholar, 29Pitcher J.A. Touhara K. Payne E.S. Lefkowitz R.J. J. Biol. Chem. 1995; 270: 11707-11710Abstract Full Text Full Text PDF PubMed Scopus (331) Google Scholar, 30Hyvonen M. Macias M.J. Nilges M. Oschkinat H. Saraste M. Wilmanns M. EMBO J. 1995; 14: 4676-4685Crossref PubMed Scopus (309) Google Scholar, 31Harlan J.E. Hajduk P.J. Yoon H.S. Fesik S.W. Nature. 1994; 371: 168-170Crossref PubMed Scopus (687) Google Scholar)in vitro. N-terminal regions of the PH domain of phospholipase C-δ1 (PLCδ1) (28Lomasney J.W. Cheng H.-F. Wang L.-P. Liu S.-M. Fesik S.W. King K. J. Biol. Chem. 1996; 271: 25316-25326Abstract Full Text Full Text PDF PubMed Scopus (107) Google Scholar), β-adrenergic receptor kinase (29Pitcher J.A. Touhara K. Payne E.S. Lefkowitz R.J. J. Biol. Chem. 1995; 270: 11707-11710Abstract Full Text Full Text PDF PubMed Scopus (331) Google Scholar), β-spectrin (30Hyvonen M. Macias M.J. Nilges M. Oschkinat H. Saraste M. Wilmanns M. EMBO J. 1995; 14: 4676-4685Crossref PubMed Scopus (309) Google Scholar), pleckstrin, Tsk (T-cell-specific kinase), and Ras GTPase-activating protein (31Harlan J.E. Hajduk P.J. Yoon H.S. Fesik S.W. Nature. 1994; 371: 168-170Crossref PubMed Scopus (687) Google Scholar) bind to inositol phospholipids. The affinity of PH domains for PI-4-P, PI-4,5-P2, PI-3-P, PI-3,4-P2, and PI 3,4,5-trisphosphate varies with the type of protein (32Rameh L.E. Arvidsson A. Carraway III, K.L. Couvillon A.D. Rathbun G. Crompton A. VanRenterghem B. Czech M.P. Ravichandran K.S. Burakoff S.J. Wang D.-S. Chen C.-S. Cantley L.C. J. Biol. Chem. 1997; 272: 22059-22066Abstract Full Text Full Text PDF PubMed Scopus (427) Google Scholar). This means that rapid cellular changes in the levels of the inositol phospholipids could affect the location and regulation of specific PH domain-containing proteins. Identifying PH domains and their ligand affinities should increase the understanding of how a protein is regulated. The PH domains of the PI 4-kinases have been described based only on primary sequence homology with other PH domains and have not been characterized biochemically. Here we show biochemical and molecular evidence for a large molecular mass PI 4-kinase in both carrot (DcPI4Kα) andArabidopsis (AtPI4Kα), and we show for the first time the affinity of a PI 4-kinase PH domain for specific phosphoinositides. The active enzyme was purified using antibodies raised against the expressed conserved domains. The molecular mass of the PI 4-kinase was estimated to be 205 kDa based on Western blot analysis of the purified protein. Western blots also indicated thatDcPI4Kα is associated with an F-actin fraction. More important, using a new technique, Fat Western blotting, we determined that the recombinant carrot PI 4-kinase PH domain binds specifically to phosphatidic acid (PA), PI-4-P, and PI-4,5-P2. The lipid binding data give new insights into potential mechanisms for regulating PI 4-kinase activity and its distribution. Total RNA was extracted from carrot cells grown in suspension culture (33Chen Q. Boss W.F. Plant Physiol. ( Bethesda ). 1990; 94: 1820-1829Crossref PubMed Scopus (39) Google Scholar) by hot borate/phenol/chloroform extraction (34Hall T.C. Ma Y. Buchbinder B.U. Pyne J.W. Sun S.M. Bliss F.A. Proc. Natl. Acad. Sci. U. S. A. 1978; 75: 3196-3200Crossref PubMed Scopus (164) Google Scholar, 35Perera I. Zielinski R. Plant Physiol. ( Bethesda ). 1992; 100: 812-819Crossref PubMed Scopus (19) Google Scholar). cDNA was synthesized from 5 μg of total RNA by Moloney murine leukemia virus reverse transcriptase (Promega) and primed with random hexamers (Boehringer Mannheim) as described (36Sambrook J. Fritsch E.F. Maniatis T. Molecular Cloning: A Laboratory Manual. 2nd Ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY1989Google Scholar). Amplification of cDNA by the polymerase chain reaction was achieved with degenerate oligonucleotides deduced from conserved amino acid sequences of known PI 4-kinases. The conserved regions were used by Nakagawa et al. (19Nakagawa T. Goto K. Kondo H. J. Biol. Chem. 1996; 271: 12088-12094Abstract Full Text Full Text PDF PubMed Scopus (96) Google Scholar) to clone the rat PI 4-kinase. The sequences of these regions are (V/T)GDDCRQ and HIDFGF(M/V). Arabidopsis codon usage was followed to design the degenerate primers, and EcoRI sites were added to the 5′-ends of the primers to facilitate subcloning of PCR products into pBluescript (Stratagene). The sequences of the primers, using the International Union of Biochemistry code for degeneracy, were CGG AAT TCR YTG GWG AYG AYT GYC GTC AR for the sense primer and CGG AAT TCN ATR AAW CCR AAR TCD ATR TG for the antisense primer. The PCRs containing 10 μl of the cDNA synthesis mixture, 20–25 pmol of each primer, and 5 units of Taq polymerase (Promega) were amplified by 25 cycles of the following: 97 °C for 30 s, 45 °C for 1 min, and 72 °C for 1 min. The PCR products were resolved by agarose gel (1%, w/v) electrophoresis, gel-purified, digested with EcoRI, and subcloned into pBluescript. Sequence of the cDNA was determined by the dideoxy chain termination method (37Sanger F. Nicklen S. Coulson A.R. Proc. Natl. Acad. Sci. U. S. A. 1977; 74: 5463-5468Crossref PubMed Scopus (55549) Google Scholar) using the Sequenase kit (U. S. Biochemical Corp.). After determining the sequence of the PCR product, gene-specific primers were used to amplify cDNA 3′ and 5′ to the original PCR product by the rapid amplification of cDNA ends (RACE) method exactly as described previously (38Frohman M.A. Methods Enzymol. 1993; 218: 340-356Crossref PubMed Scopus (468) Google Scholar). The ArabidopsisPI 4-kinase was cloned by using the carrot 5′-RACE product as a probe to screen an Arabidopsis λYES cDNA library (a gift of Dr. Ralph Dewey, North Carolina State University). The probe was labeled with [α-32P]dCTP and random hexamers. The plated library (3 × 106 clones) was hybridized to the carrot cDNA at 55 °C for 16 h in hybridization buffer containing 6× saline/sodium phosphate/EDTA (SSPE; 1× SSPE = 10 mm NaH2PO4, 1 mm EDTA, and 149 mm NaCl) and 5× Denhardt's solution (100× Denhardt's solution = 2% (w/v) fatty acid-free bovine serum albumin, 2% (w/v) polyvinylpyrrolidone, 2% (w/v) Ficoll 400, 0.5% (w/v) SDS, and 100 μg of calf thymus DNA (Sigma)). The final wash was in 1× SSPE and 0.1% (w/v) SDS at 55 °C for 1 h. The nylon membrane was exposed to x-ray film for 24 h at −80 °C. Two hybridization-positive clones were carried through three successive screens. The larger clone was 2.5 kb and was used as a probe to screen an Arabidopsis λZap II cDNA library that had been selected for large cDNAs (39Kieber J.J. Rothenberg M. Roman G. Feldman K. Ecker J.R. Cell. 1993; 72: 427-441Abstract Full Text PDF PubMed Scopus (1525) Google Scholar). Again, two positive clones were carried through three sequential screening steps, and the largest clone (3.1 kb) was analyzed for its complete sequence by the Iowa State Sequencing Facility. Total RNA was fractionated by formaldehyde-containing agarose gel electrophoresis (40Zielinski R.E. Plant Physiol. ( Bethesda ). 1987; 84: 937-943Crossref PubMed Google Scholar). The RNA was transferred by capillary transfer and UV-cross-linked to nylon membrane and then hybridized with the Arabidopsis cDNA labeled by random priming with [α-32P]dCTP. Hybridization was at 42 °C in hybridization buffer containing 50% (v/v) formamide. The final wash of the blot was in 0.1× SSPE and 0.1% (w/v) SDS at 65 °C for 1 h. The nylon was then exposed to x-ray film for 3 days at −80 °C. A cDNA encoding the carrot PI 4-kinase PH domain was generated by PCR amplification with primers that flanked either end of the domain sequence. The sequences of the primers were CGG GAT CCC CCC TGG TTA GGC AAC ACA TT (sense) and GGA ATT CCA ACC TTG AAA ACG CAA GCT T (antisense). The primers contained BamHI (sense primer) and EcoRI (antisense primer) sites on their 5′-ends to facilitate directional subcloning into the bacterial expression vector pRSET-A (Invitrogen). The PCR product was gel-purified, digested with BamHI andEcoRI, and ligated into pRSET-A. BL21(DE3) pLys S cells were transformed with the recombinant plasmid, and expression was induced with the addition of isopropyl-β-d-thiogalactopyranoside (1 mm final concentration) to the cell culture. Bacterial cells expressing the His-tagged PH domain were lysed by sonication and solubilized in 6 m guanidine hydrochloride, and the recombinant polypeptide was purified by metal affinity chromatography using ProBond resin (Invitrogen). Because the PH domain was insoluble, purification was carried out under denaturing conditions with solutions containing 8 m urea. Column fractions were dialyzed sequentially to remove urea and to promote refolding. Tomato eEF-1α (a gift from Christine K. Shewmaker, Calgene Inc.) was expressed and purified using the same protocol. Total microsomes were prepared from carrot suspension culture cells 5 days after transfer or from whole Arabidopsis thaliana plants. Suspension culture cells were filtered by gravity and homogenized in an equal volume of buffer containing 10 mm KCl, 1 mm EDTA, 1 mm MgCl2, 50 mm Tris (pH 7.5), 95 mm LiCl, 2 mm EGTA, polyvinylpolypyrrolidone (0.1 g/g of cells), 8% (w/v) sucrose, 1 mm dithiothreitol, 2 μg/ml aprotinin, 0.1 mm phenylmethylsulfonyl fluoride, 1 mg/100 ml leupeptin, and 2 mm benzamidine. Homogenization was with an equal volume of 0.2-mm glass beads in a Virtis homogenizer in 30-s pulses for 2 min at 4 °C. Arabidopsis plants were coarsely macerated and ground in a Virtis homogenizer with an equal volume of buffer containing 3 mm EDTA, 2 mmEGTA, 30 mm Tris (pH 7.4), 250 mm sucrose, 14 mm β-mercaptoethanol, 2 mm dithiothreitol, 2 μg/ml aprotinin, 0.1 mm phenylmethylsulfonyl fluoride, 1 mg/100 ml leupeptin, and 2 mm benzamidine. The homogenate was centrifuged at 2000 × g for 5 min. The resultant supernatant was centrifuged at 40,000 × g for 60 min to obtain a microsomal fraction. Microsomes were resuspended in 30 mm Tris (pH 7.4). F-actin-rich fractions were prepared from the microsomal fraction isolated from 5-day-old carrot suspension culture cells as described previously (10Tan Z. Boss W.F. Plant Physiol. ( Bethesda ). 1992; 100: 2116-2120Crossref PubMed Scopus (73) Google Scholar). PCR was used to amplify the reading frame of the largest AtPI4Kα clone. The primers used were CGG GAT CCG TTC AGT CAC ATA TAT TAG AA (sense) and G GAA TTC TTA CTT CTC GAT GCC TTG (antisense). An internalBamHI site 45 nucleotides upstream of the region encoding the lipid kinase unique domain and the EcoRI site of the antisense primer allowed the PCR product to be digested with these two enzymes, purified, and ligated into pRSET-B. Expression and purification of the recombinant protein were exactly the same as for the recombinant PH domain described above, except that the protein was not dialyzed. Instead it was concentrated in a Centricon 10 (Amicon, Inc.), and resolved by SDS-PAGE so that ∼50 μg of recombinant protein were present in each lane of the gel. The gel was stained with 0.05% (w/v) Coomassie Brilliant Blue R-250 in water and washed copiously with water until the bands were visible. The bands containing the recombinant protein were excised from the gel and sent to Zeneca LifeScience Molecules for injection into two rabbits (662 and 663). The rabbits were given seven boosts of the recombinant protein over the course of 3 months. Sera from test bleeds and production bleeds were analyzed for cross-reactivity to the recombinant protein by immunoblotting (data not shown). Antiserum from test bleed 2 of rabbit 662 was purified for IgG on a protein A-Sepharose column (Sigma). Unspecific and His tag-generated antibodies were removed by incubating the purified IgG with an acetone precipitate of E. coli cells expressing His-tagged eEF-1α and removing the aggregates by centrifugation (41Harlow E. Lane D. Antibodies: A Laboratory Manual. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY1988Google Scholar). A protein A-Sepharose-antibody affinity column was made by direct coupling with dimethyl pimelimidate (Sigma) as described previously (41Harlow E. Lane D. Antibodies: A Laboratory Manual. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY1988Google Scholar). Production bleed antisera from both rabbits (0.5 ml total) were pooled and added to 1 ml of protein A-Sepharose beads in 30 mm Tris (pH 7.4). After coupling the antibody to the beads, the column was washed with 20 bed volumes of 30 mm Tris (pH 8.0). The efficiency of coupling of antibody to protein A beads was analyzed by SDS-PAGE before and after the addition of dimethyl pimelimidate. Heavy chain IgG bands were present at 55 kDa before coupling, but not after. Arabidopsis microsomes (12.5 mg) were solubilized for 30 min at 4 oC in buffer used to solubilize cytoskeletal proteins (2% (v/v) Triton X-100, 100 mm Tris (pH 7.4), 10 mm EGTA, 1 mm phenylmethylsulfonyl fluoride, 150 μg/ml leupeptin, and 670 μg/ml DNase I) (42Carraway K.L. Carraway C.A.C. The Cytoskeleton: A Practical Approach. Oxford University Press, New York1992Google Scholar). Solubilized microsomes were centrifuged at 40,000 × g for 30 min. The supernatant was incubated with antibody-coupled beads in a 10 × 33-mm column resuspended in 1 bed volume of 100 mm Tris (pH 7.4) at 4 °C with shaking for 2 h. The bed was allowed to settle, and the flow-through fraction was collected. The column was washed with 10 bed volumes of 100 mm Tris (pH 7.4). In addition, to prepare the column for elution and to ensure adequate washing, the column was washed with 10 mm phosphate buffer (pH 7.0) until the flow-through fraction had a spectrophotometric absorbance reading of <0.010 at 280 nm. Bound proteins were eluted with 100 mm glycine (pH 3.0). Fractions of 1 bed volume were collected, immediately neutralized with 0.05 volume of 1m phosphate (pH 8.0), and analyzed by SDS-PAGE and immunoblotting and for PI 4-kinase activity. Each fraction eluted from the immunoaffinity column was assayed in duplicate (60 μl/assay) to determine the PI 4-kinase activity. The reaction mixture contained final concentrations of 7.5 mm MgCl2, 1 mm sodium molybdate, 0.5 mg/ml PI, 0.1% (v/v) Triton X-100, 0.9 mmATP, 30 mm Tris (pH 7.2), and 20 μCi of [γ-32P]ATP (7000 Ci/mmol) in a total volume of 100 μl. Stock PI (5 mg/ml) was solubilized in 1% (v/v) Triton X-100. The reactions were incubated at 25 °C for 2 h with intermittent shaking. The reactions were stopped with 1.5 ml of ice-cold CHCl3/MeOH (1:2) and kept at 4 °C until the lipids were extracted. Lipids were extracted as described previously (9Cho M.H. Shears S.B. Boss W.F. Plant Physiol. ( Bethesda ). 1993; 103: 637-647Crossref PubMed Scopus (52) Google Scholar). Extracted lipids were vacuum-dried, solubilized in CHCl3/MeOH (2:1), and spotted onto Whatman LK5D silica gel plates that had been completely dried in a microwave oven for 5 min after presoaking in 1% (w/v) potassium oxalate for 80 s. The lipids were separated in either a CHCl3/MeOH/NH4OH/H2O (86:76:6:16) solvent system (9Cho M.H. Shears S.B. Boss W.F. Plant Physiol. ( Bethesda ). 1993; 103: 637-647Crossref PubMed Scopus (52) Google Scholar) or a borate/pyridine-based solvent (43Walsh J.P. Caldwell K.K. Majerus P.W. Proc. Natl. Acad. Sci. U. S. A. 1991; 88: 9184-9187Crossref PubMed Scopus (106) Google Scholar) and quantitated with a Bioscan System 500 Imaging Scanner. The plates were subsequently exposed to a phosphor screen for 2 days and visualized by a Storm PhosphorImager (Molecular Dynamics, Inc.). Carrot microsomes were solubilized in 1% (v/v) Triton X-100 at 4 °C overnight. To preclear unspecific antibodies and antigens, solubilized microsomes were incubated for 1 h on ice with 0.2 volume of preimmune serum from rabbit 662. 0.33 volume of protein A-Sepharose was added and incubated for 1.5 h at 4 °C with shaking. The beads were pelleted, and the supernatant was saved and used for subsequent steps. Immunoprecipitation, as described previously (41Harlow E. Lane D. Antibodies: A Laboratory Manual. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY1988Google Scholar), was carried out by adding to the supernatant either preimmune serum or partially purified antiserum from test bleed 2 of rabbit 662 (described above). The protein A-antibody-antigen complex was washed three times with 30 mm Tris (pH 7.2) and resuspended in SDS-PAGE sample buffer for subsequent analysis by electrophoresis and immunoblotting. Protein was separated by SDS-PAGE using 8% (w/v) polyacrylamide and transferred onto polyvinylidene difluoride membrane (44Bjerrum O.J. Schafer-Nielsen C. Dunn M.J. Analytical Electrophoresis. Verlag Chemie, Weinheim1986: 315Google Scholar). The membrane was incubated for 1 h with anti-AtPI4Kα antiserum (1:1000) at 25 °C. Cross-reactivity was detected by incubation with goat anti-rabbit IgG, F(ab′)2 conjugated to horseradish peroxidase (Pierce), and subsequent chemiluminescent detection by exposing the blot to X-Omat AR film (Eastman Kodak Co.) for the amount of time indicated. Phospholipids were from Sigma, except for PI-3-P and PI-3,4-P2, which were from Matreya, Inc., and NBD-labeled PA, NBD-labeled phosphatidylcholine, and rhodamine-labeled phosphatidylethanolamine, which were from Avanti Polar Lipids. Phospholipids were solubilized in chloroform as stock solutions of 1 mg/ml. A minimum of 10 μl containing 0.5, 1.0, or 5.0 μg of lipid were spotted onto nitrocellulose (NitroBind, MSI) at a time. The membrane and lipids were dried at 24 °C for 1 h. The nitrocellulose was incubated with 3% (w/v) fatty acid-free bovine serum albumin (isolated by cold ethanol precipitation; Sigma A-6003) in TBST (10 mm Tris (pH 8.0), 140 mm NaCl, and 0.1% (v/v) Tween 20) for 1 h and then placed in a solution containing the His-tagged fusion proteins (PH domain or eEF-1α) diluted in TBST (0.5 μg/ml) at 4 °C overnight with shaking. The nitrocellulose was washed with TBST three times for 10 min each and then incubated with T7 tag monoclonal antibody (Novagen) to the His-tagged region diluted 1:10,000 in TBST for 1 h at 24 °C. The nitrocellulose was washed three times for 10 min in TBST at 24 °C and then incubated with goat anti-mouse IgG conjugated to horseradish peroxidase (Pierce) at a titer of 1:30,000 in TBST for 1 h at 24 °C. The nitrocellulose was washed again in TBST three times for 10 min and then incubated for 5 min in a 1:1 mixture of peroxidase substrate and luminol/enhancer (Pierce) for subsequent chemiluminescent detection. The nitrocellulose was exposed to X-Omat AR film for 0.5–5 min as indicated. Using degenerate primers based on highly conserved regions of yeast PIK1 and STT4 PI 4-kinase lipid kinase domains, we amplified a cDNA of 394 nucleotides from carrot RNA. Sequence analysis of this PCR product showed that the deduced amino acid sequence was 50% identical and 64% similar to yeast STT4 and only 35% identical and 54% similar toArabidopsis PI 3-kinase (AtVPS34). 5′- and 3′-RACE were used to amplify regions of sequence beyond this initial PCR product. The 3′-RACE product was 1.1 kb in size and spanned the rest of the catalytic domain and extended through the 3′-untranslated region to the poly(A) tail. The 5′-RACE product contained 1.4 kb and had sequence homology to the lipid kinase unique domain and PH domain of the other PI 4-kinases reported in GenBankTM. The 5′-RACE product from carrot was used as a probe to screen anArabidopsis λYES cDNA library. Two positiv DA - 1998/8/28/ PY - 1998/8/28/ DO - 10.1074/jbc.273.35.22761 VL - 273 IS - 35 SP - 22761-22767 SN - 0021-9258 ER - TY - JOUR TI - Resistance to belly rot in cucumber identified through field and detached-fruit evaluations AU - Uchneat, MS AU - Wehner, TC T2 - JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE AB - Belly rot, caused by the fungal pathogen Rhizoctonia solani Kühn., is a severe disease in many regions that produce cucumber ( Cucumis sativus L.). Annual crop loss to belly rot is commonly 5% to 10%, but losses as high as 80% can occur in individual fields. There are no resistant cultivars, so fungicides are used to provide partial control. Genetic resistance in an acceptable cultivar would be more desirable and economical. Studies were conducted in Summers 1991 and 1992 to screen promising germplasm for belly rot resistance using field and detached-fruit screening methods. In 1991, 105 cultigens (cultivars, breeding lines, and plant introduction accessions) were evaluated for belly rot resistance. The tests were repeated in 1992 with 63 cultigens, including the most resistant cultigens identified in 1991 and appropriate controls. Several cultigens were identified as potential sources of resistance genes. Pickling cucumbers showing resistance included PI 197085, PI 271328, and an F 4 selection of PI 197087 × PI 280096. Slicing cucumbers with resistance included `Marketmore 76' and the F 1 of Gy 14 × PI 197087. Belly rot resistance was not correlated with other horticultural traits measured, including fruit type, skin type, spine color, and firmness. The resistant cultigens identified should be useful for developing cucumber cultivars with enhanced resistance to Rhizoctonia solani. DA - 1998/1// PY - 1998/1// DO - 10.21273/jashs.123.1.78 VL - 123 IS - 1 SP - 78-84 SN - 0003-1062 KW - Cucumis sativus KW - Rhizoctonia solani KW - disease resistance KW - cucurbits ER - TY - PCOMM TI - On the effect of estrogen receptor agonists and antagonists on the mouse hair follicle cycle AU - Smart, RC AU - Oh, HS AB - The experiments we reported in our letter were described as executed, and the mouse strains investigated were chosen for the reasons stated. The experiments were planned and conducted completely independent of one another but, unfortunately, the same mistake was made in both cases – the concentrations used were not as reported in the original report. Although we take responsibility for this oversight, we also recognize that the dosage listing is not entirely conventional to the field. Before starting the repeat experiments we consulted several independent researchers outside our respective laboratories; in all cases the understood dosage was interpreted exactly as we had. When we repeated the work using the twice weekly protocol and the concentrations used originally by Oh and Smart (Proc Natl Acad Sci 93:12525), β-estradiol did indeed inhibit the normal progression of spontaneous anagen in pigmented mice (C57B16). From additional and subsequent studies that we have since executed, we have learned several important features about the role of estrogen receptor-mediated signaling in murine hair growth control that we did not formerly appreciate. We would hope to share these data in a future report. We are indebted to Drs. Oh and Smart for calling our attention to this interesting phenomenon and regret the confusion our mistake might have caused. Note from the Editor: Due to an editorial office error, Drs. Smart and Oh were not given a chance to reply to the original letter about their paper by Drs. Stenn, Paus, and Filippi (J Invest Dermatol, 110:95 1998). We apologize to all the authors for this mistake. DA - 1998/7// PY - 1998/7// DO - 10.1046/j.1523-1747.1998.00257.x SP - 175-175 ER - TY - JOUR TI - Neural control of cell size in the corpora allata during the reproductive cycle of the cockroach Diploptera punctata (Dictyoptera : Blaberidae) AU - Chiang, AS AU - Holbrook, GL AU - Cheng, HW AU - Schal, C T2 - INVERTEBRATE REPRODUCTION & DEVELOPMENT AB - Summary Rising and subsequent falling rates of juvenile hormone (JH) synthesis occurred concurrently with synchronous growth and atrophy of CA cells during the ovarian cycle in mated adult females of Diploptera punctata. Ultrastructural observations revealed that growth of CA cells resulted from synchronous proliferation of cellular machinery required for JH synthesis. Cell growth was suppressed in CA of virgin females, in which rates of JH synthesis remained low, but was stimulated by mating or by severance of nerves leading from the brain to the CA. Atrophy of CA cells during declining rates of JH synthesis was due to synchronous autophagy of cellular organelles. While the mechanism initiating autophagy is unclear, it is independent of nervous connections between the CA and brain. We propose that under normal physiological conditions the quantity of JH synthesized by a corpus allatum is determined largely by the total amount of cellular machinery available for JH production. Therefore, the cycle of JH synthesis in mated adult females of D. punctata is regulated mainly through synchronous proliferation of cell components (under neural inhibition) followed by synchronous autophagy (nerve independent). In the course of this study, we have found that individual CA cells from D. punctata, like those from Blattella germanica, retain their ability to synthesize JH III following enzymatic dissociation of the CA. DA - 1998/1// PY - 1998/1// DO - 10.1080/07924259.1998.9652339 VL - 33 IS - 1 SP - 25-34 SN - 0168-8170 KW - cell size KW - cell growth KW - corpora allata KW - juvenile hormone KW - autophagy KW - atrophy KW - cockroach KW - Diploptera punctata ER - TY - JOUR TI - Manipulating natural enemies by plant variety selection and modification: A realistic strategy? AU - Bottrell, DG AU - Barbosa, P AU - Gould, F T2 - ANNUAL REVIEW OF ENTOMOLOGY AB - The host plants of arthropod pests may affect parasitoids and predators directly or indirectly, through multitrophic interactions. Direct plant effects may involve simple mechanisms such as reduced parasitoid searching efficiency caused by trichomes. Multitrophic effects often involve complex interactions that are not well understood, and their impact on natural enemies and biological control are difficult to predict. Knowledge of the direct and multitrophic effects creates opportunities to increase the effectiveness of natural enemies by incorporating natural enemy-enhancing traits into crop plants. The strategy may have potential for both generalist and specialist natural enemies, but the enemies' behavior and other factors will affect the results. Although combining natural enemies and plant resistance may slow the adaptation of some insect pests, it may speed up adaptations of others. A better understanding of plant/pest/natural enemy evolution is necessary to predict how to combine natural enemies and plant resistance for the best long-term results. DA - 1998/// PY - 1998/// DO - 10.1146/annurev.ento.43.1.347 VL - 43 SP - 347-367 SN - 1545-4487 KW - plant breeding KW - plant resistance natural enemy interactions KW - parasitoids KW - predators ER - TY - JOUR TI - Juvenile hormone synthesis in relation to corpus allatum development in embryos of the viviparous cockroach Diploptera punctata AU - Holbrook, GL AU - Chiang, AS AU - Lee, YJ AU - Lin, CY AU - Schal, C T2 - INVERTEBRATE REPRODUCTION & DEVELOPMENT AB - Summary Few studies have addressed endocrinology of the corpora allata (CA) in insect embryos. We now report on development and biosynthetic activity of CA in embryos of a viviparous cockroach, Diploptera punctata. When newly-eclosed adult females of D. punctata were mated, they oviposited and gave birth, respectively, about 8 and 73 days later; thus, gestation and corresponding embryogenesis lasted approximately 65 days. Dorsal closure, which coincides with differentiation of the CA, was concluded when embryos were about 13 days old and had completed 20% of embryogenesis. Reverse phase-high performance liquid chromatography revealed that embryonic CA released predominantly juvenile hormone III (JH) in vitro. Furthermore, an in vitro radiochemical assay showed that between day 28 of embryogenesis (43% of embryonic development completed) and hatch rates of JH synthesis rose, plateaued and then fell. When CA activity was increasing or was high, from day 28 to 54 (83% development), mitosis occurred at low and constant rates within embryonic CA, and corpus allatum cell number increased gradually. Between days 56 (86% development) and 60 (92% development), CA activity fell to a low level, rates of mitosis peaked, and corpus allatum cell number rose rapidly. Throughout embryogenesis, CA volume increased in parallel with CA cell number, suggesting that glandular growth was due largely to cell proliferation. Although CA activity and volume changed considerably in embryos, the diameter of corpus allatum cells, as measured from enzymatically dissociated CA, remained surprisingly constant at 11–12 μm on days 32, 46 and 60 (49, 71 and 92% development). Ultrastructural observations confirmed the large size of cells in low-activity CA of 60-day-old embryos and also showed that these cells, like those in highly active CA of 46-day-old embryos, contained abundant cytoplasm, ribosomes, microtubules and mitochondria. Key words: Cockroachviviparityembryocorpora allatajuvenile hormonecell proliferationultrastructure DA - 1998/1// PY - 1998/1// DO - 10.1080/07924259.1998.9652343 VL - 33 IS - 1 SP - 69-79 SN - 2157-0272 KW - cockroach KW - viviparity KW - embryo KW - corpora allata KW - juvenile hormone KW - cell proliferation KW - ultrastructure ER - TY - JOUR TI - Interaction of flesh color genes in watermelon AU - Henderson, WR AU - Scott, GH AU - Wehner, TC T2 - JOURNAL OF HEREDITY AB - Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] flesh color is controlled by several genes to produce red, orange, salmon yellow, canary yellow, or white. The objective of these experiments was to study the interaction of three independently reported gene loci, each having two or three alleles: C (canary yellow) versus c (red), y (salmon yellow) versus Y (red) versus Yo (orange), and i (inhibitory to C) versus l (noninhibitory to C). The interaction of C, y, yo, and i is of interest to those developing new cultivars of watermelon and has not been reported previously. Five crosses were used to study gene action: Yellow Baby x Tendersweet Orange Flesh, Yellow Doll x Tendersweet Orange Flesh, Yellow Baby x Golden Honey, Yellow Doll x Golden Honey, and Yellow Baby x Sweet Princess. Based on performance of PA, PB, F1, F2, BC1A, and BC1B, the parents have the following genotypes: Yellow Baby = CCYYII, Yellow Doll = CCYYII, Tendersweet Orange Flesh = ccyoyoII, Golden Honey = ccyyII, and Sweet Princess = ccYYii. Segregation of flesh color in the progeny of the five families supported the previous report of a multiple allelic series at the y locus, where Y (red) was dominant to yo (orange) and y (salmon yellow). In conclusion, epistasis is involved in the genes for major flesh colors in watermelon, with ii inhibitory to CC (canary yellow), resulting in red flesh, and CC (in the absence of ii) epistatic to YY, producing canary flesh. DA - 1998/// PY - 1998/// DO - 10.1093/jhered/89.1.50 VL - 89 IS - 1 SP - 50-53 SN - 0022-1503 ER - TY - JOUR TI - Glycosyl hydrolases from hyperthermophilic microorganisms AU - Bauer, MW AU - Driskill, LE AU - Kelly, RM T2 - CURRENT OPINION IN BIOTECHNOLOGY AB - Glycosyl hydrolases from hyperthermophiles are, thus far, the most widely studied enzyme class from these organisms. Not only are there many biotechnological opportunities for these enzymes, but the rapidly increasing amount of information about their genetic, biochemical and biophysical characteristics (recently genomic sequencing data for both P. furiosus and P. horikoshi have been published on the Internet) make them ideal candidates for the study of biocatalysis and protein thermostability at extremely high temperatures. DA - 1998/4// PY - 1998/4// DO - 10.1016/S0958-1669(98)80106-7 VL - 9 IS - 2 SP - 141-145 SN - 0958-1669 ER - TY - JOUR TI - Gene silencing from plant DNA carried by a Geminivirus AU - Kjemtrup, S AU - Sampson, KS AU - Peele, CG AU - Nguyen, LV AU - Conkling, MA AU - Thompson, WF AU - Robertson, D T2 - PLANT JOURNAL AB - Summary The geminivirus tomato golden mosaic virus (TGMV) replicates in nuclei and expresses genes from high copy number DNA episomes. The authors used TGMV as a vector to determine whether episomal DNA can cause silencing of homologous, chromosomal genes. Two markers were used to asses silencing: (1) the sulfur allele ( su ) of magnesium chelatase, an enzyme required for chlorophyll formation; and (2) the firefly luciferase gene ( luc ). Various portions of both marker genes were inserted into TGMV in place of the coat protein open‐reading frame and the constructs were introduced into intact plants using particle bombardment. When TGMV vectors carrying fragments of su (TGMV::su) were introduced into leaves of wild type Nicotiana benthamiana , circular, yellow spots with an area of several hundred cells formed after 3‐5 days. Systemic movement of TGMV::su subsequently produced varigated leaf and stem tissue. Fragments that caused silencing included a 786 bp 5' fragment of the 1392 bp su cDNA in sense and anti‐sense orientation, and a 403 bp 3' fragment. TGMV::su‐induced silencing was propogated through tissue culture, along with the viral episome, but was not retained through meiosis. Systemic downregulation of a constitutively expresse luciferase transgene in plants was achieved following infection with TGMV vectors carrying a 623 bp portion of luc in sense or anti‐sense orientation. These results establish that homologous DNA sequences localized in nuclear episomes can modulate the expression of active chromosomal genes. DA - 1998/4// PY - 1998/4// DO - 10.1046/j.1365-313X.1998.00101.x VL - 14 IS - 1 SP - 91-100 SN - 0960-7412 ER - TY - JOUR TI - Fruit yield and yield component means and correlations of four slicing cucumber populations improved through six to ten cycles of recurrent selection AU - Cramer, CS AU - Wehner, TC T2 - JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE AB - Increased fruit yield in slicing cucumber ( Cucumis sativus L.) has been difficult to achieve since yield is quantitatively inherited with low heritability. From 1981 to 1993, four slicing cucumber populations differing in their genetic diversity (wide, medium, elite, and `Beit Alpha') were advanced through six to ten cycles of modified half-sib recurrent selection. The objectives of this research were to determine 1) the fruit yield and yield component means; 2) the correlations between yield components, between yield traits, and between components and yield; and 3) the change in means and correlations with selection for improved yield of four slicing cucumber populations. In 1994 and 1995, four families were randomly selected from three cycles (early, intermediate, and late) from each population and self-pollinated. Thirty plants from each S 1 family were evaluated in 3.1-m plots in Spring and Summer 1995 and 1996 at the Horticultural Crops Research Station in Clinton, N.C. Plants were harvested and data were collected on number of branches per plant and nodes per branch, proportion of pistillate nodes, fruit set and shape, and total, early, and marketable yield. When averaged over all populations, seasons, and years, fruit yield and quality increased with selection while yield components remained unchanged with selection. Fruit yield and components differed between populations, seasons, and years. Most correlations between yield components and between yield components and fruit yield were weak, and strong correlations varied between populations, seasons, and yield components. Indirect selection of proportion of pistillate nodes has potential for improving yield for certain population-season combinations. Selection weakened many strong correlations between yield components and between yield and components. Changes in correlations often did not correspond with changes in trait means. Based on this research, selection for yield components would not be advantageous for improving fruit yield in all slicing cucumber populations. Additional yield components, yield component heritability, and better component selection methods need to be determined before component selection can be used to improve fruit yield. DA - 1998/5// PY - 1998/5// DO - 10.21273/jashs.123.3.388 VL - 123 IS - 3 SP - 388-395 SN - 2327-9788 KW - Cucumis sativus KW - cucurbitaceae KW - earliness KW - fruit shape KW - quantitative genetics KW - vegetable breeding ER - TY - JOUR TI - Biological control of wirestem on cabbage using binucleate Rhizoctonia spp. AU - Ross, RE AU - Keinath, AP AU - Cubeta, MA T2 - CROP PROTECTION AB - Binucleate Rhizoctonia (BNR) was investigated for biological control of wirestem on cabbage, caused by Rhizoctonia solani anastomosis group (AG) 4. Cabbage seedlings colonized with BNR isolate B901 (AG-G), 232-CG (AG-G), or PDS26E (AG unknown) were transplanted into infested field plots. In the fall of 1994 and 1995, BNR isolate B901 reduced wirestem incidence and area under the disease progress curve (AUDPC) compared with the non-treated control, although not to the level of the fungicide standard, pentachloronitrobenzene (PCNB). In the spring of 1995, all three BNR isolates and PCNB significantly reduced wirestem incidence and AUDPC compared with the non-treated control. Overall disease incidence was low in this season. Marketable weights in some treatments with PDS26E were greater than the non-treated control or PCNB. In the spring of 1996, although no treatments reduced wirestem, PCNB and 232-CG had the highest yields. BNR appears to have the potential to control wirestem on cabbage when low soil temperatures after planting or low precipitation during the growing season limit disease development. DA - 1998/3// PY - 1998/3// DO - 10.1016/S0261-2194(97)00109-9 VL - 17 IS - 2 SP - 99-104 SN - 1873-6904 KW - biological control KW - binucleate Rhizoctonia KW - Rhizoctonia solani ER - TY - JOUR TI - Analytical investigation of heat transfer in Couette flow through a porous medium utilizing the Brinkman-Forchheimer-extended Darcy model AU - Kuznetsov, AV T2 - ACTA MECHANICA DA - 1998/// PY - 1998/// DO - 10.1007/BF01379647 VL - 129 IS - 1-2 SP - 13-24 SN - 0001-5970 ER - TY - JOUR TI - Analytical investigation of Couette flow in a composite channel partially filled with a porous medium and partially with a clear fluid AU - Kuznetsov, AV T2 - INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER AB - In this study, a new thermal lattice Boltzmann model (TLBM) is developed to simulate conjugate heat transfer in a microchannel heat sink (MCHS) with porous ribs and pulsatile flow inlet. The examined parameters include the rib to channel height ratio (Hr*), Strouhal number (St), and Reynolds number (Re), which are varied from 0.25 to 0.75, 0 to 3.2, and 100 to 300, respectively. The proposed TLBM is based on the double distribution function framework and capable of addressing heat transfer in combined fluid and porous media conditions. The simulation data show that the flow pulsation inside MCHS with porous ribs not only improves the bulk mean temperatures but also eliminates the rib recirculation zones at some phases, which promotes both the local and overall heat transfer. For fixed Re, the overall Nusselt number (Nu‾/Nu0) and Fanning friction coefficient (f‾/f0) increase and then decrease with increasing St. The maximum values appear at St = 2. For fixed Re and St, the thermal performance factor (TPF) displays a single peak trend with Hr* and the optimal TPF of 2.2 occurs at Hr*=0.5. In addition, compared with the previous ribbed, baffled, and porous MCHSs, the proposed porous rib design under pulsating conditions reports the highest Nu‾/Nu0 of 13.4 in the range of f‾/f0≤200. Finally, the correlations of Nu‾/Nu0 and f‾/f0 with Re, St, and Hr* for the present MCHS are established for the first time, with average differences below 6.7% and 12.4%, respectively. DA - 1998/8// PY - 1998/8// DO - 10.1016/S0017-9310(97)00296-2 VL - 41 IS - 16 SP - 2556-2560 SN - 0017-9310 ER - TY - JOUR TI - A recessive gene for revolute cotyledons in cucumber AU - Wehner, TC AU - Staub, JE AU - Liu, JS T2 - JOURNAL OF HEREDITY AB - An experiment was conducted to determine the genetics of the revolute cotyledon trait in the cucumber inbred NCG-093 (short petiole mutant). NCG-903 was crossed with inbred WI 2757 to produce F1, F2 and BC1 generations for evaluation. The F1 progeny had normal cotyledons, and the segregation of the F2 progeny fit a ratio of 3 normal: 1 revolute cotyledons. The BC1A(F1 X WI 2757) progeny had normal cotyledons, and the segregation of the BC1B(F1 X NCG-093) fit a ratio of 1 normal:1 revolute cotyledons. We concluded that revolute cotyledons in NCG-093 was conferred by a single recessive gene, revolute cotyledons-2, for which we propose the symbol rc-2. A mutant from Burpless Hybrid was previously described as having revolute cotyledons, controlled by the rc gene. However, that mutant was apparently lost, making it impossible to test allelism with the gene in NCG-093. DA - 1998/// PY - 1998/// DO - 10.1093/jhered/89.1.86 VL - 89 IS - 1 SP - 86-87 SN - 0022-1503 ER - TY - JOUR TI - Prevalence of heartworm infection in cats with signs of cardiorespiratory abnormalities AU - Atkins, C.E. AU - DeFrancesco, T. AU - Miller, M.W. AU - Meurs, K.M. AU - Keene, B. T2 - Journal of the American Veterinary Medical Association DA - 1998/2/15/ PY - 1998/2/15/ VL - 212 IS - 4 SP - 517–520 ER - TY - JOUR TI - PCR amplification of ribosomal DNA for species identification in the plant pathogen genus Phytophthora AU - Ristaino, J.B. AU - Madritch, M. AU - Trout, C.L. AU - Parra, G. T2 - Applied and Environmental Microbiology DA - 1998/// PY - 1998/// VL - 64 IS - 3 SP - 948-954 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031934217&partnerID=MN8TOARS ER - TY - JOUR TI - Isolation and characterization of Thermococcus barossii, sp. nov., a hyperthermophilic Archaeon isolated from a hydrothermal vent flange formation AU - Duffaud, GD AU - d'Hennezel, OB AU - Peek, AS AU - Reysenbach, AL AU - Kelly, RM T2 - SYSTEMATIC AND APPLIED MICROBIOLOGY AB - A new hyperthermophilic microorganism, Thermococcus barossii, was isolated from rock fragments of a hydrothermal vent flange formation, located along the East Pacific Rise of the Juan de Fuca Ridge. This organism is obligately anaerobic and grows over a temperature range of at least 60–92 °C in artificial seawater-based media, containing elemental sulfur, tryptone and yeast extract. The addition of a maltooligosaccharide mixture and tungsten to this medium improved growth to some extent. At the Topt for growth (82.5 °C), cell densities as high as 4×108 cells/ml could be obtained in 18-liter batch fermentations, with a doubling time of approximately 40 minutes, if culture access to elemental sulfur was sufficient. In continuous culture at the same temperature, comparable cell densities could be obtained but only at slower growth rates. Morphologically, T. barossii is coccoid-shaped, forming irregularly-shaped spheres; under optimal conditions, these coccoids become more regular and smaller, a characteristic of other hyperthermophilic archaea. Negatively-stained preparations showed no pili or flagella associated with the cell surface. 16S rRNA sequencing reveals that T. barossii is most similar to Thermococcus celer (99.7%). Yet, further comparisons with T. celer showed that T. barossii is a new Thermococcus species: different growth temperature optimum (82.5 °C vs. 88 °C), obligate requirement for sulfur, higher G+C content (60% vs. 56.7%) and 47.7% DNA-DNA hybridization. The nucleotide and translated amino acid sequence for the gene encoding a DNA polymerase from T. barossii was compared to sequences of related genes from other Thermococcales. The polymerase phylogenies were congruent with those obtained from the 16S rRNA phylogenetic analyses. Based on the high degree of similarity among members of the genus Termococcus for the criteria used thus far, aspects of enzymology may be an important mechanism of differentiating one species from another. DA - 1998/3// PY - 1998/3// DO - 10.1016/S0723-2020(98)80007-6 VL - 21 IS - 1 SP - 40-49 SN - 0723-2020 KW - Thermococcus barossii KW - hyperthermophiles KW - 16S rRNA KW - growth physiology ER - TY - JOUR TI - Individual members of the light-harvesting complex II chlorophyll a/b binding protein gene family in pea (Pisum sativum) show differential responses to ultraviolet-B radiation AU - MacKerness, S. A. H. AU - Liu, L. S. AU - Thomas, B. AU - Thompson, William AU - Jordan, B. R. AU - White, M. J. T2 - Physiologia Plantarum AB - Light‐harvesting complex II chlorophyll a/b ‐binding protein (Lhcb) mRNA levels are differentially affected by ultraviolet‐B radiation (UV‐B, 280‐320 nm) at different stages of development of pea ( Pisum sativum L. cv. Feltham first) seedlings. Addition of UV‐B radiation to the light periods of diurnal cycles of white light resulted in reduction of total Lhcb mRNAs in green leaves but a transient increase in etiolated buds. The aims of this study were to determine the stage during de‐etiolation at which supplementary UV‐B began to inhibit Lhcb gene expression, and to determine whether differential regulation of individual Lhcb genes could explain the differential response to supplementary UV‐B at different developmental stages. All seven Lhcb mRNAs were shown to increase in etiolated buds transferred to a diurnal cycle with supplementary UV‐B during the light periods, but were greatly reduced in green leaves given the same treatment. Therefore, the different responses of total Lhcb mRNA levels to UV‐B radiation in green leaves and etiolated buds are not primarily due to the expression of different members of the Lhcb gene family at different developmental stages. However, the Lhcb genes could be divided into two groups based on their sensitivities to UV‐B. Transcripts from the three genes, Lhcb1 * 2 , Lhcb1 * 3 and Lhcb1 * 5 , which were undetectable in dark‐grown etiolated buds, exhibited stronger responses to supplementary UV‐B in green leaves than the four genes, Lhcb1 * 1 , Lhcb1 * 4 , Lhcb2 * 1 and Lhcb3 * 1 , which showed low levels of initial transcript accumulation in dark‐grown etiolated buds. The effect of UV‐B on Lhcb mRNA levels were, however, correlated with chlorophyll content, suggesting that the developmental stage of chloroplasts may be important in determining the responses of the Lhcb genes to supplementary UV‐B radiation in pea seedlings. DA - 1998/// PY - 1998/// DO - 10.1034/j.1399-3054.1998.1030311.x VL - 103 IS - 3 SP - 377–384 ER - TY - JOUR TI - A major gene for powdery mildew resistance transferred to common wheat from wild einkorn wheat AU - Shi, AN AU - Leath, S AU - Murphy, JP T2 - PHYTOPATHOLOGY AB - A major gene for resistance to wheat powdery mildew (Blumeria graminis f. sp. tritici = Erysiphe graminis f. sp. tritici) has been successfully transferred into hexaploid common wheat (Triticum aestivum, 2n = 6x = 42, AABBDD) from wild einkorn wheat (Triticum monococcum subsp. aegilopoides, 2n = 2x = 14, AA). NC96BGTA5 is a germ plasm line with the pedigree Saluda × 3/PI427662. The response patterns for powdery mildew resistance in NC96BGTA5 were tested with 30 differential isolates of B. graminis f. sp. tritici, and the line was resistant to all tested isolates. The analyses of P 1 , P 2 , F 1 , F 2 , and BC 1 F 1 populations derived from NC96BGTA5 revealed two genes for wheat powdery mildew resistance in the NC96BGTA5 line. One gene, Pm3a, was from its recurrent parent Saluda, and the second was a new gene introgressed from wild einkorn wheat. The gene was determined to be different from Pm1 to Pm21 by gene-for-gene and pedigree analyses. The new gene was identified as linked to the Pm3a gene based on the F 2 and BC 1 F 1 populations derived from a cross between NC96BGTA5 and a susceptible cultivar NK-Coker 68-15, and the data indicated that the gene was located on chromosome 1A. It is proposed that this new gene be designated Pm25 for wheat powdery mildew resistance in NC96BGTA5. Three random amplified polymorphic DNA markers, OPX06 1050 , OPAG04 950 , and OPAI14 600 , were found to be linked to this new gene. DA - 1998/2// PY - 1998/2// DO - 10.1094/PHYTO.1998.88.2.144 VL - 88 IS - 2 SP - 144-147 SN - 0031-949X ER - TY - JOUR TI - The promise of forest biotechnology AU - Sederoff, R. R. T2 - Paper Age DA - 1998/// PY - 1998/// IS - 1998 Aug. SP - 13-18 ER - TY - JOUR TI - Diploid hybrid speciation in Penstemon (Scrophulariaceae) AU - Wolfe, AD AU - Xiang, QY AU - Kephart, , SR T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - Hybrid speciation has played a significant role in the evolution of angiosperms at the polyploid level. However, relatively little is known about the importance of hybrid speciation at the diploid level. Two species of Penstemon have been proposed as diploid hybrid derivatives based on morphological data, artificial crossing studies, and pollinator behavior observations: Penstemon spectabilis (derived from hybridization between Penstemon centranthifolius and Penstemon grinnellii ) and Penstemon clevelandii (derived from hybridization between P. centranthifolius and P. spectabilis ). Previous studies were inconclusive regarding the purported hybrid nature of these species because of a lack of molecular markers sufficient to differentiate the parental taxa in the hybrid complex. We developed hypervariable nuclear markers using inter-simple sequence repeat banding patterns to test these classic hypotheses of diploid hybrid speciation in Penstemon . Each species in the hybrid complex was genetically distinct, separated by 10–42 species-specific inter-simple sequence repeat markers. Our data do not support the hybrid origin of P. spectabilis but clearly support the diploid hybrid origin of P. clevelandii . Our results further suggest that the primary reason diploid hybrid speciation is so difficult to detect is the lack of molecular markers able to differentiate parental taxa from one another, particularly with recently diverged species. DA - 1998/4/28/ PY - 1998/4/28/ DO - 10.1073/pnas.95.9.5112 VL - 95 IS - 9 SP - 5112-5115 SN - 0027-8424 ER - TY - JOUR TI - Two signaling mechanisms for activation of alpha(M)beta(2) avidity in polymorphonuclear neutrophils AU - Jones, SL AU - Knaus, UG AU - Bokoch, GM AU - Brown, EJ T2 - JOURNAL OF BIOLOGICAL CHEMISTRY AB - Circulating polymorphonuclear neutrophils (PMN) are quiescent, nonadherent cells that rapidly activate at sites of inflammation, where they develop the capacity to perform a repertoire of functions that are essential for host defense. Induction of integrin-mediated adhesion, which requires an increase in integrin avidity, is critical for the development of these effector functions. Although a variety of stimuli can activate integrins in PMN, the signaling cascades involved are unclear. Phosphatidylinositol (PI) 3-kinase has been implicated in integrin activation in a variety of cells, including PMN. In this work, we have examined activation of the PMN integrin αMβ2, assessing both adhesion and generation of the epitope recognized by the activation-specific antibody CBRM1/5. We have found that PI 3-kinase has a role in activation of αMβ2 by immune complexes, but we have found no role for it in αMβ2 activation by ligands for trimeric G protein-coupled receptors, including formylmethionylleucylphenylalanine (fMLP), interleukin-8, and C5a. Cytochalasin D inhibition suggests a role for the actin cytoskeleton in immune complex activation of αMβ2, but cytochalasin has no effect on fMLP-induced activation. Similarly, immune complex activation of the Rac/Cdc42-dependent serine/threonine kinase Pak1 is blocked by PI 3-kinase inhibitors, but fMLP-induced activation is not. These results demonstrate that two signaling pathways exist in PMN for activation of αMβ2. One, induced by FcγR ligation, is PI 3-kinase-dependent and requires the actin cytoskeleton. The second, initiated by G protein-linked receptors, is PI 3-kinase-independent and cytochalasin-insensitive. Pak1 may be in a final common pathway leading to activation of αMβ2. Circulating polymorphonuclear neutrophils (PMN) are quiescent, nonadherent cells that rapidly activate at sites of inflammation, where they develop the capacity to perform a repertoire of functions that are essential for host defense. Induction of integrin-mediated adhesion, which requires an increase in integrin avidity, is critical for the development of these effector functions. Although a variety of stimuli can activate integrins in PMN, the signaling cascades involved are unclear. Phosphatidylinositol (PI) 3-kinase has been implicated in integrin activation in a variety of cells, including PMN. In this work, we have examined activation of the PMN integrin αMβ2, assessing both adhesion and generation of the epitope recognized by the activation-specific antibody CBRM1/5. We have found that PI 3-kinase has a role in activation of αMβ2 by immune complexes, but we have found no role for it in αMβ2 activation by ligands for trimeric G protein-coupled receptors, including formylmethionylleucylphenylalanine (fMLP), interleukin-8, and C5a. Cytochalasin D inhibition suggests a role for the actin cytoskeleton in immune complex activation of αMβ2, but cytochalasin has no effect on fMLP-induced activation. Similarly, immune complex activation of the Rac/Cdc42-dependent serine/threonine kinase Pak1 is blocked by PI 3-kinase inhibitors, but fMLP-induced activation is not. These results demonstrate that two signaling pathways exist in PMN for activation of αMβ2. One, induced by FcγR ligation, is PI 3-kinase-dependent and requires the actin cytoskeleton. The second, initiated by G protein-linked receptors, is PI 3-kinase-independent and cytochalasin-insensitive. Pak1 may be in a final common pathway leading to activation of αMβ2. Phagocytes are essential cells in host defense of metazoan organisms because they prevent the systemic spread of invading pathogens. Phagocytic cells such as monocytes and polymorphonuclear leukocytes (PMN) 1The abbreviations used are: PMN, polymorphonuclear neutrophil(s); IC, immune complexes; IIC, insoluble immune complexes; fMLP, formylmethionylleucylphenylalanine; IAP, integrin-associated protein (CD47); HLA, human leukocyte antigen; PI, phosphatidylinositol; PMA, phorbol 12-myristate 13-acetate; MBP, myelin basic protein; BSA, bovine serum albumin; FCS, fetal calf serum; IL, interleukin; mAb, monoclonal antibody; PT, pertussis toxin; HBSS, Hanks' buffered salts solution; PIP3, PI (3,4,5)-trisphosphate; PDGF, platelet-derived growth factor; RT, room temperature; PKC, protein kinase C. circulate throughout tissues to be able to initiate a rapid response to injury and infection. At sites of inflammation and infection, these cells perform many functions, including ingestion and killing of invading organisms, generation of inflammatory mediators, and initiation of an immune response. The acquisition of these effector functions required for successful host defense is called phagocyte activation. Adhesion is required to develop the full effector phenotype in phagocytes and, indeed, in other leukocytes as well (reviewed in Refs. 1Larson R.S. Springer T.A. Immunol. Rev. 1990; 114: 181-217Crossref PubMed Scopus (519) Google Scholar and 2Berton G. Yan S. Fumagalli L. Lowell C. Int. J. Clin. Lab. Res. 1996; 26: 160-177Crossref PubMed Scopus (97) Google Scholar). We have used human PMN as a model cell to study how adhesion regulates this phenotypic change and the critical role of leukocyte integrins in this process. PMN express β1, β2, and β3 integrins, but integrins other than the β2 family (also known as LeuCAM or CD18 integrins) are present in low number. In particular, the CD18 integrin αMβ2 plays a central role in PMN activation at sites of inflammation (3Anderson D. Schmalstieg F. Arnaout M. Kohl S. Dickey W. Abramson J. Springer T. Boxer L. Hollers J. Smith C. J. 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Although these data strongly suggest that PI 3-kinase activity is an important early event in inside-out signaling regulating integrin-mediated adhesion, the mechanism by which PI 3-kinase regulates adhesion is not clear nor is the generality of the requirement for PI 3-kinase in integrin activation. PDGF receptors, for example, can activate β1integrins by PI 3-kinase-dependent and -independent mechanisms (44Kinashi T. Escobedo J.A. Williams L.T. Takatsu K. Springer T.A. Blood. 1995; 86: 2086-2090Crossref PubMed Google Scholar). Whether PI 3-kinase has a role in αMβ2activation in PMN is not known. FcγR-induced phagocytosis (46Ninomiya N. Hazeki K. Fukui Y. Seya T. Okada T. Hazeki O. Ui M. J. Biol. Chem. 1994; 269: 22732-22737Abstract Full Text PDF PubMed Google Scholar), fMLP-induced respiratory burst activity (32Okada T. Sakuma L. Fukui Y. Hazeki O. Ui M. J. Biol. Chem. 1994; 269: 3563-3567Abstract Full Text PDF PubMed Google Scholar, 33Arcaro A. Wymann M.P. Biochem. 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While this intracellular pool is not required for PMN binding to endothelia or for aggregation (50Scheiffenbaum B. Moser R. Patarroyo M. Fehr J. J. Immunol. 1989; 142: 3537-3545PubMed Google Scholar, 51Buyon J.P. Abramson S.N. Philips M.R. Slade S.G. Ross G.D. Weissman G. Winchester R.J. J. Immunol. 1988; 140: 3156-3160PubMed Google Scholar, 52Vedder N.B. Harlan J.M. J. Clin. Invest. 1988; 81: 676-682Crossref PubMed Scopus (243) Google Scholar), it is necessary for optimal adhesion (53Hughes B. Hollers J. Crockett-Torabi E. Smith C. J. Clin. Invest. 1992; 90: 1687-1696Crossref PubMed Scopus (163) Google Scholar). The role of PI 3-kinase in regulating the expression of this intracellular pool at the plasma membrane is unknown. We tested the importance of PI 3-kinase in regulating integrin activation in PMN in two well characterized experimental systems for activating β2 integrin-dependent adhesion. FcγR ligation activates αMβ2 through initiation of a tyrosine kinase cascade, whereas fMLP requires a heterotrimeric G-protein to initiate signaling in PMN. Our results suggest that two pathways exist for activating β2integrin-dependent adhesion in PMN. The FcγR-initiated pathway is dependent on PI 3-kinase activity and is inhibited by cytochalasin D, whereas the fMLP-induced increase in αMβ2 avidity is independent of PI 3-kinase and unaffected by cytochalasin D. FcγR-mediated enhancement of αMβ2 expression is inhibited by wortmannin, but increased expression is not required for adhesion. Importantly, both pathways activate Pak1, a recently described serine/threonine kinase implicated in membrane ruffling and focal adhesion formation (54Sells M. Knaus U. Bagrodia S. Ambrose D. Bokoch G. Chernoff J. Curr. Biol. 1997; 7: 202-210Abstract Full Text Full Text PDF PubMed Scopus (579) Google Scholar). FcγR-induced activation of Pak1 is PI 3-kinase-dependent, whereas fMLP-induced activation of Pak1 is independent of PI 3-kinase, potentially placing Pak1 in a common pathway leading to activation of αMβ2avidity. These data demonstrate that there is more than one molecular pathway for inside-out signaling and suggest that the effects of tyrosine kinase cascades, and G protein-dependent signaling on integrin function may be mediated by distinct mechanisms that converge on a common pathway involving Pak1. Cytochalasin D, PMA, fMLP, dimethyl sulfoxide, rabbit polyclonal anti-BSA antiserum, C5a, BSA, poly-l-lysine, glutaraldehyde, fluorescein isothiocyanate-conjugated F(ab′)2 sheep anti-mouse IgG antibody, MBP, and EGTA were from Sigma. [γ-32P]ATP was from ICN (Irvine, CA). Phosphate-buffered saline and 10× stock HBSS were from Life Technologies, Inc. Protein A-conjugated Sepharose, Ficoll-Paque, and Dextran T500 were obtained from Amersham Pharmacia Biotech (Uppsala Sweden). IL-8 was purchased from Calbiochem (San Diego, CA), and pertussis toxin was obtained from List Biologicals (Campbell, CA). 1 m stock Hepes and 7.5% sodium bicarbonate were from BioWhittaker (Walkersville, MD). Wortmannin and LY294002 were obtained from LC Laboratories (Woburn, MA). Fetal calf serum (FCS) was from Hyclone (Logan, UT). Calcein and Celltracker Green CMFDA were from Molecular Probes (Eugene OR). Tissue culture plates and 96-well Immulon 2 plates were from Becton-Dickinson (Franklin Lakes, NJ) and Dynatech (Chantilly, VA), respectively. Monoclonal Abs 3G8 (anti-FcγRIII) (55Fleit H.B. Wright S.D. Unkeless J.C. Proc. Natl. Acad. Sci. U. S. A. 1982; 79: 3275-3279Crossref PubMed Scopus (437) Google Scholar), IV.3 (anti-FcγRII) (56Looney R.J. Ryan D.H. Takahashi K. Fleit H.B. Cohen H.J. Abraham G.N. Anderson C.L. J. Exp. Med. 1986; 163: 826-836Crossref PubMed Scopus (116) Google Scholar), IB4 (anti-β2, CD18) (57Wright S.D. Rao P.E. Wesley C. van Voorhis W.C. Craigmyle L.S. 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Science. 1995; 269: 221-223Crossref PubMed Scopus (358) Google Scholar) were prepared as described. Human PMN were isolated from whole blood exactly as described (63Gresham H.D. Clement L.D. Volanakis J.E. Brown E.J. J. Immunol. 1987; 139: 4159-4166PubMed Google Scholar) except hypotonic lysis was not performed. PMN were greater than 98% viable as indicated by the exclusion of trypan blue dye. Cells were suspended in HBSS (Hanks' buffered salts solution with 20 mm Hepes and 8.9 mm sodium bicarbonate) with 1.0 mmMg2+ and 1 mm Ca2+(HBSS2+) or HBSS with 0.5 mm Mn2+ for adhesion assays and flow cytometry. Purified human PMN (1 × 107/ml) were incubated with 2 μg/ml calcein in HBSS for 30 min at RT. The cells were washed once and resuspended in HBSS2+ at 2 × 106/ml. For adhesion experiments in the presence of Mn2+, the cells were washed in HBSS with 2 mm EGTA once, HBSS2+ or HBSS + 0.5 mm Mn2+ once, and resuspended in HBSS2+ or HBSS + 0.5 mm Mn2+. Cells were treated with wortmannin or LY294002 at the indicated concentration or Me2SO as a control for 15 min at 37 °C or with pertussis toxin (2 μg/ml) or control buffer in HBSS + 1% human serum albumin for 2 h at 37 °C. For antibody inhibition experiments, cells were incubated with 10 or 25 μg/ml of the appropriate antibody for 15 min at RT. 1 × 105 cells were added per well to Immulon 2 plates coated with BSA and a 1:25 dilution of rabbit anti-BSA to form IC or 5% FCS as described (64Graham I.L. Anderson D.C. Holers V.M. Brown E.J. J. Cell Biol. 1994; 127: 1139-1147Crossref PubMed Scopus (87) Google Scholar). For PMA or fMLP-stimulated adhesion, PMA (50 μg/ml final), fMLP (100 nm final), or Me2SO control was added to the cells after allowing them to settle onto FCS-coated wells for 6 min at RT. The cells were incubated at 37 °C for the indicated time. The fluorescence (485 nm excitation and 530 nm emission wavelengths) was measured using a fMax fluorescence plate reader (Molecular Devices, Sunnyvale, CA) before and after washing twice with 150 μl of phosphate-buffered saline. Percent adhesion was calculated by dividing the fluorescence after washing by the fluorescence before washing. In preliminary experiments, fluorescence was shown to be linearly related to cell number (data not shown). Purified PMN (4 × 106/ml in HBSS2+) were treated with wortmannin (100 nm) or Me2SO for 15 min at 37 °C. For experiments with pertussis toxin, 1 × 107 cells/ml were incubated with pertussis toxin (2 μg/ml) or control buffer for 2 h at 37 °C and then washed. 2 × 106 cells were then treated with 30 μl insoluble IC (IIC) prepared exactly as described (65Rosales C. Brown E.J. J. Biol. Chem. 1992; 267: 5265-5271Abstract Full Text PDF PubMed Google Scholar), fMLP (100 nm), C5a (50 nm), IL-8 (100 nm), or PMA (50 μg/ml) at 37 °C for 10 min, placed on ice, washed once with ice-cold wash buffer (phosphate-buffered saline, 1% FCS, 0.1% sodium azide), and resuspended in 100 μl of wash buffer plus primary antibody (25 μg/ml). Cells were incubated with primary antibody for 40 min on ice and then washed twice. After incubation with fluorescein isothiocyanate-conjugated F(ab′)2 sheep anti-mouse IgG secondary antibody at a 1:50 dilution in 200 μl of wash buffer for 20 min on ice, cells were washed twice, and the relative fluorescence of gated PMN was measured using a EPICS XL (Coulter, Miami, FL) flow cytometer. For Mn2+ experiments, cells were treated with wortmannin, washed, resuspended in HBSS2+ or HBSS + 0.5 mm Mn2+, and incubated for 10 min at 37 °C and then placed on ice. Primary antibody was added directly to the cells (25 μg/ml) for 40 min on ice, washed twice, and incubated with secondary antibody as above. All washes were done with HBSS containing appropriate divalent cations. Purified PMN were suspended at 1 × 107 cells/ml in HBSS2+. After pretreatment with wortmannin, LY294002, pertussis toxin, or control buffer as described above, 7.5 × 106 cells were added to 6-well plates coated with IC or FCS as described (66Jones S. Brown E. J. Biol. Chem. 1996; 271: 14623-14630Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar) or stimulated in suspension with fMLP (100 nm). After incubating at 37 °C, the cells were lysed by adding cold 2× lysis buffer (1% Nonidet P-40, 150 mm NaCl, 5 mm EGTA, 50 mm NaF, 5 mm sodium pyrophosphate, 1 mmNaVO4, 5 mg/ml leupeptin and aprotinin, and 1 mm diisopropyl fluorophosphate, final concentration) for 30 min on ice. Pak1 was immunoprecipitated from the lysates with 5 μl of rabbit anti-Pak1 antiserum and 40 μl of a 1:1 slurry of Protein A-Sepharose for 2 h at 4 °C. The immunoprecipitates were washed four times with lysis buffer and two times with reaction buffer (25 mm Tris-HCl, pH 7.4, 10 mm MgCl2). Kinase reactions were performed with the Pak1 immunoprecipitates by adding 30 μl of reaction buffer with 2.5 μg of MBP to the beads, incubating for 10 min at RT, followed by 10 μl of reaction buffer containing 100 μm cold ATP and 0.5 μCi of [γ-32P]ATP (4500 Ci/mmol) for a final ATP concentration of 25 μm. The reactions were incubated for 20 min at 30 °C, after which the reaction was stopped with 50 μl of SDS-polyacrylamide gel electrophoresis sample buffer containing 10% SDS. Phosphorylation of MBP was detected by SDS-polyacrylamide gel electrophoresis, transfer to polyvinylidene difluoride membranes, and autoradiography. For each experiment, Pak1 protein was immunoblotted using anti-Pak1 antiserum (1:1000) primary antibody, horseradish peroxidase-conjugated goat anti-rabbit antiserum (20 μg/ml) secondary antibody, and enhanced chemiluminescence substrate (ECL, Pierce) to ensure that equivalent amounts of kinase protein were added to each in vitro kinase reaction. PI 3-kinase activity is required for adhesion of a variety of cell types to fibronectin (37Serve H. Yee N. Stella G. Sepp-Lorenzino L. Tan J. Besmer P. EMBO J. 1995; 14: 473-483Crossref PubMed Scopus (201) Google Scholar, 38Shimizu Y. Mobley J. Finkelstein L. Chan A. J. Cell Biol. 1995; 131: 1867-1880Crossref PubMed Scopus (109) Google Scholar), agonist-induced aggregation and up-regulation of activated αIIbβ3 expression in platelets (39Chacko G. Brandt J. Coggeshall K. Anderson C. J. Biol. Chem. 1996; 271: 10775-10781Abstract Full Text Full Text PDF PubMed Scopus (106) Google Scholar, 40Kovacsovics T.J. Bachelot C. Toker A. Vlahos C.J. 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We used two pharmacologic inhibitors of PI 3-kinase, wortmannin and LY294002, to test the hypothesis that PI 3-kinase activity is required for FcγR-induced, β2 integrin-dependent adhesion to IC in PMN. Adhesion of control PMN to IC was maximal by 15 min and sustained for up to 40 min (Ref. 8Graham I.L. Lefkowith J.B. Anderson D.C. Brown E.J. J. Cell Biol. 1993; 120: 1509-1517Crossref PubMed Scopus (65) Google Scholar and Fig. 1 A). PMN pretreated with wortmannin or LY294002 initially adhered to IC-coated surfaces identically to control cells, even at inhibitor concentrations up to 1 and 200 μm, respectively (Fig. 1, A and C, and data not shown). However, after 10 min, adhesion of both wortmannin- and LY294002-treated PMN to IC decreased until there was no specific, IC-dependent adhesion by 40 min (Fig. 1,A and C). Similar kinetics of adhesion were obtained with PMN pretreated with wortmannin for 30 min. Non-adherent, wortmannin-treated PMN excluded trypan blue dye, demonstrating that they were viable. Although the wortmannin and LY294002-treated PMN cells initially (<10 min) spread as well as control cells on IC, after 10 min spreading decreased until by 40 min the cells were completely round (data not shown). In contrast, PMA-induced adhesion to, and spreading on, FCS were not affected at DA - 1998/4/24/ PY - 1998/4/24/ DO - 10.1074/jbc.273.17.10556 VL - 273 IS - 17 SP - 10556-10566 SN - 0021-9258 UR - http://europepmc.org/abstract/med/9553116 ER - TY - JOUR TI - Modeling the dynamics of adaptation to transgenic maize by European corn borer (Lepidoptera : Pyralidae) AU - Onstad, DW AU - Gould, F T2 - JOURNAL OF ECONOMIC ENTOMOLOGY AB - Journal Article Modeling the Dynamics of Adaptation to Transgenic Maize by European Corn Borer (Lepidoptera: Pyralidae) Get access David W. Onstad, David W. Onstad Center for Economic Entomology, Illinois Natural History Survey, Champaign, IL 61820 Search for other works by this author on: Oxford Academic PubMed Google Scholar Fred Gould Fred Gould 1 Center for Economic Entomology, Illinois Natural History Survey, Champaign, IL 61820 1Department of Entomology, North Carolina State University, Raleigh, NC 27695. Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 91, Issue 3, 1 June 1998, Pages 585–593, https://doi.org/10.1093/jee/91.3.585 Published: 01 June 1998 DA - 1998/6// PY - 1998/6// DO - 10.1093/jee/91.3.585 VL - 91 IS - 3 SP - 585-593 SN - 1938-291X KW - Ostrinia nubilalis KW - host plant KW - resistance KW - simulation model KW - Bacillus thuringiensis KW - population genetics ER - TY - JOUR TI - The reovirus protein mu2, encoded by the M1 gene, is an RNA-binding protein AU - Brentano, L. AU - Noah, D. L. AU - Brown, E. G. AU - Sherry, B. T2 - Journal of Virology DA - 1998/// PY - 1998/// VL - 72 IS - 10 SP - 8354-8357 ER - TY - JOUR TI - Two special cucumber populations: NCH1 and NCBA1 AU - Wehner, T. C. T2 - HortScience DA - 1998/// PY - 1998/// VL - 33 IS - 4 SP - 766-768 ER - TY - JOUR TI - Social influences on nymphal development in the cockroach, Diploptera punctata AU - Holbrook, GL AU - Schal, C T2 - PHYSIOLOGICAL ENTOMOLOGY AB - Solitary male nymphs of the cockroach Diploptera punctata (Eschscholtz) (Blattaria: Blaberidae) took significantly longer to reach adulthood than males paired with either a male or female nymph or grouped with four other male nymphs since birth. When isolated throughout nymphal development, 15.8% of males passed through 3 stadia before adult eclosion, and the remainder went through 4 stadia. In contrast, 61.3% of paired males became adults in 3 stadia. Males need not, however, be isolated or paired for the entire nymphal period to express isolated or paired patterns of development. About 60% of males paired in just the first stadium or its initial 9 days became adults in 3 stadia, and only 20.4% of males isolated in the first stadium and the first 3 days of the second reached adulthood within 3 stadia. Although the first stadium was a critical period in which social condition determined the course of future development, analyses of covariance showed that isolated males gained less weight than paired ones, not only in the first stadium, but in the second as well. Moreover, the degree of growth of a male in the second stadium, measured as either weight gain or relative growth rate, did not depend on the male’s social condition in the first stadium, because isolated second‐instar males grew less than paired ones, even when both sets of insects had been paired in the first stadium. Female nymphal development, unlike that of males, was not greatly affected by social factors. DA - 1998/6// PY - 1998/6// DO - 10.1046/j.1365-3032.1998.232077.x VL - 23 IS - 2 SP - 121-130 SN - 1365-3032 KW - cockroach KW - group effect KW - isolation KW - nymphal development KW - growth rate KW - life history KW - beetle cockroach KW - Diploptera punctata ER - TY - PAT TI - Pathogen-resistant transgenic plants AU - Conkling, M. A. AU - Opperman, C. H. AU - Taylor, C. G. C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - PAT TI - PCR assays for phytophthora species AU - Ristaino, J. B. C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Nature wars: People vs. Pests, by M.L. Winston AU - Gould, F. L. T2 - Issues in Science and Technology DA - 1998/// PY - 1998/// VL - 14 IS - 3 SP - 86 ER - TY - JOUR TI - Natural resistance of Prunus to adult Japanese beetles AU - Patton, C. A. AU - Ranney, T. G. AU - Burton, J. D. AU - Walgenbach, J. F. T2 - American Nurseryman DA - 1998/// PY - 1998/// VL - 187 IS - 10 SP - 70-71 ER - TY - PAT TI - Method of altering lignin in trees AU - MacKay, J. AU - O'Malley, D. AU - Whetten, R. AU - Sederoff, R. C2 - 1998/// DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Finding and using hyperthermophilic enzymes AU - Adams, MWW AU - Kelly, RM T2 - TRENDS IN BIOTECHNOLOGY AB - Recent developments have enhanced the prospects for the discovery of hyperthermophilic enzymes. This is important because the intrinsic basis underlying the extraordinary thermostability of hyperthermophilic enzymes has yet to be revealed, and so engineering this characteristic into less thermophilic enzymes is not possible at this time. Successful efforts to clone and express the genes encoding hyperthermophilic enzymes in mesophilic hosts have improved the availability of high-temperature biocatalysts. The remaining task is the identification of opportunities to make strategic use of the thermoactivity and thermostability of hyperthermophilic enzymes. DA - 1998/8// PY - 1998/8// DO - 10.1016/S0167-7799(98)01193-7 VL - 16 IS - 8 SP - 329-332 SN - 0167-7799 ER - TY - JOUR TI - Bt resistance management AU - McGaughey, WH AU - Gould, F AU - Gelernter, W T2 - NATURE BIOTECHNOLOGY DA - 1998/2// PY - 1998/2// DO - 10.1038/nbt0298-144 VL - 16 IS - 2 SP - 144-146 SN - 1087-0156 ER -