TY - JOUR TI - Bartonella spp Antibodies and DNA in Aqueous Humour of Cats AU - Lappin, M R AU - Kordick, D L AU - Breitschwerdt, E B T2 - Journal of Feline Medicine and Surgery AB - Bartonella spp antibodies were measured in the serum and aqueous humour of cats with and without uveitis and polymerase chain reaction (PCR) for Bartonella spp DNA was performed on aqueous humour from most of the cats. Serum and aqueous humour were assayed from 49 client-owned cats with uveitis, 49 healthy shelter cats, and nine cats experimentally inoculated with either B henselae or B clarridgeiae, 454 days after inoculation. An aqueous antibody coefficient (C value) was calculated for cats positive for Bartonella spp antibodies in the aqueous humour. Ocular production of Bartonella spp IgG (C value >1) was detected in seven of 49 cats with uveitis, none of 49 healthy shelter cats, and four of nine experimentally inoculated cats. The organism was detected by PCR in the aqueous humour of three of 24 cats with uveitis, one of 49 healthy shelter cats, and four of nine experimentally inoculated cats. Bartonella spp infect the eyes of some cats following natural exposure or experimental inoculation and may cause uveitis in some cats. DA - 2000/3// PY - 2000/3// DO - 10.1053/jfms.2000.0067 VL - 2 IS - 1 SP - 61-68 J2 - Journal of Feline Medicine and Surgery LA - en OP - SN - 1098-612X 1532-2750 UR - http://dx.doi.org/10.1053/jfms.2000.0067 DB - Crossref ER - TY - CONF TI - Early termination in Ben-Or/Tiwari sparse interpolation and a hybrid of Zippel's algorithm AU - Kaltofen, Erich AU - Lee, Wen-shin AU - Lobo, Austin A. T2 - the 2000 international symposium AB - Article Early termination in Ben-Or/Tiwari sparse interpolation and a hybrid of Zippel's algorithm Share on Authors: Erich Kaltofen Department of Mathematics, North Carolina State University, Raleigh, North Carolina Department of Mathematics, North Carolina State University, Raleigh, North CarolinaView Profile , Wen-shin Lee Department of Mathematics, North Carolina State University, Raleigh, North Carolina Department of Mathematics, North Carolina State University, Raleigh, North CarolinaView Profile , Austin A. Lobo Dept. of Mathematics and Computer Science, Washington College, Chestertown, Maryland Dept. of Mathematics and Computer Science, Washington College, Chestertown, MarylandView Profile Authors Info & Claims ISSAC '00: Proceedings of the 2000 international symposium on Symbolic and algebraic computationJuly 2000 Pages 192–201https://doi.org/10.1145/345542.345629Online:01 July 2000Publication History 22citation308DownloadsMetricsTotal Citations22Total Downloads308Last 12 Months14Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access C2 - 2000/// C3 - Proceedings of the 2000 international symposium on Symbolic and algebraic computation symbolic and algebraic computation - ISSAC '00 DA - 2000/// DO - 10.1145/345542.345629 PB - ACM Press SN - 1581132182 UR - http://dx.doi.org/10.1145/345542.345629 DB - Crossref ER - TY - JOUR TI - New frontiers in the study of dispersal and spatial analysis of epidemics caused by species in the genus Phytophthora AU - Ristaino, Jean Beagle AU - Gumpertz, Marcia L T2 - Annual Review of Phytopathology DA - 2000/// PY - 2000/// VL - 38 IS - 1 SP - 541-576 ER - TY - JOUR TI - BIOCHEMISTRY AND CELL BIOLOGY-Commercial Fungicide Formulations Induce In Vitro Oo-spore Formation and Phenotypic Change in Mating Type in Phytophthora infestans AU - Groves, CT AU - Ristaino, JB T2 - Phytopathology DA - 2000/// PY - 2000/// VL - 90 IS - 11 SP - 1201-1208 ER - TY - JOUR TI - ADVANCES IN TEMPERATURE PREDICTIVE MODELS FOR SOIL SOLARIZATION AU - Ristaino, JB AU - Perry, KB AU - Wu, Y T2 - FAO PLANT PRODUCTION AND PROTECTION PAPERS DA - 2000/// PY - 2000/// SP - 463-471 ER - TY - JOUR TI - A history of research on the link between (micro) aggregates, soil biota and soil organic matter dynamics. AU - Babalola, OA AU - Adesodun, JK AU - Olasantan, FO AU - Adekunle, AF AU - Aggelides, SM AU - Londra, PA AU - Akintokun, AK AU - Akande, GA AU - Akintokun, PO AU - Popoola, TOS AU - others T2 - International Journal of Soil Science DA - 2000/// PY - 2000/// VL - 7 IS - 1 SP - 253-259 ER - TY - JOUR TI - Commercial fungicide formulations induce in vitro oospore formation and phenotypic change in mating type in Phytophthora infestans AU - Groves, Carol Trout AU - Ristaino, Jean Beagle T2 - Phytopathology DA - 2000/// PY - 2000/// VL - 90 IS - 11 SP - 1201-1208 ER - TY - CHAP TI - Post-Transcriptional Light Regulation of Nuclear-Encoded Genes AU - Petracek, Marie E. AU - Thompson, W. F. T2 - Genetic Engineering PY - 2000/// DO - 10.1007/978-1-4615-4199-8_1 SP - 1-10 OP - PB - Springer US SN - 9781461368847 9781461541998 UR - http://dx.doi.org/10.1007/978-1-4615-4199-8_1 DB - Crossref ER - TY - JOUR TI - Virginia pine progeny test series AU - Frampton, J. T2 - Pine Tips: Newsletter of the Eastern NC Christmas Tree Growers Association DA - 2000/// PY - 2000/// VL - 9 IS - 3 SP - 7 ER - TY - JOUR TI - The Fraser fir progeny test series AU - Frampton, J. T2 - Limbs & Needles DA - 2000/// PY - 2000/// VL - 27 IS - 3 SP - 8-10 ER - TY - JOUR TI - Propagation of Anemone x hybrida by rooted cuttings AU - Dubois, J-J B. AU - Blazich, F. A. AU - Warren, S. L. AU - Goldfarb, B. T2 - Journal of Environmental Horticulture DA - 2000/// PY - 2000/// VL - 18 SP - 79-83 ER - TY - JOUR TI - Fir species of the world AU - Frampton, J. T2 - Bulletin for American Conifer Society Bulletin DA - 2000/// PY - 2000/// VL - 17 SP - 152-155 ER - TY - JOUR TI - Alternative fir species field trial series AU - Frampton, J. T2 - Limbs & Needles DA - 2000/// PY - 2000/// VL - 27 IS - 1 SP - 6-7 ER - TY - JOUR TI - Interstock effects on strobilus initiation in topgrafted loblolly pine AU - McKeand, S. E. AU - Raley, E. M. T2 - Forest Genetics DA - 2000/// PY - 2000/// VL - 7 SP - 179-182 ER - TY - JOUR TI - Grafting loblolly pine AU - McKeand, S. E. AU - Jett, J. B. T2 - Bulletin of the American Conifer Society DA - 2000/// PY - 2000/// VL - 17 IS - 1 SP - 22-30 ER - TY - JOUR TI - Tree genomes: What will we understand about them by the year 2020 and how might we use that knowledge? AU - Sederoff, R. R. T2 - Forest genetics and sustainability AB - The purpose of this paper is to speculate about the future applications of molecular genetics to the understanding and utilization of tree genomes. Biotechnology of forest trees is a young discipline. The first genetically engineered tree, a glyphosate tolerant hybrid poplar, was produced in 1987 (Fillatti et al., 1987). Since that time, biotechnology of forest trees has incorporated new technology of genetic mapping and has now entered the era of genomics. Much of what follows here is only one person’s speculations about scientific progress into a relatively near future. In general, scientists are less effective at predicting the future of science than are writers of fiction, who are less constrained about predictions. The time frame of this paper is to look forward to the year 2020, which is approximately one rotation age for a temperate pine, and as much as four rotations for a tropical hardwood. The purpose of this short review is not to be comprehensive, nor to provide access to key references, but to provide an overview of ideas related to application to forest trees of existing technology in the relatively near future. DA - 2000/// PY - 2000/// DO - 10.1007/978-94-017-1576-8_4 SP - 23 ER - TY - JOUR TI - Root architectural plasticity to nutrient stress in two contrasting ecotypes of loblolly pine AU - Wu, R. L. AU - Grissom, J. E. AU - O'Malley, D. M. AU - McKeand, Steven T2 - Journal of Sustainable Forestry DA - 2000/// PY - 2000/// DO - 10.1300/j091v10n03_13 VL - 10 IS - 3 SP - 307 ER - TY - CHAP TI - Molecular biology of infectious disease AU - Sharp, N. J. H. T2 - Kirk's current veterinary therapy : small animal practice (13th Ed.) PY - 2000/// SP - 246 PB - Philadelphia, PA : W.B. Saunders SN - 0721655238 ER - TY - CHAP TI - Bartonella vinsonii infection in dogs AU - Pappalardo, B. L. AU - Breitschwerdt, E. B. T2 - Kirk's current veterinary therapy : small animal practice (13th Ed.) PY - 2000/// SP - 300 PB - Philadelphia, PA : W.B. Saunders SN - 0721655238 ER - TY - CHAP TI - Bartonella infections in domestic cats AU - Kordick, D. L. AU - Breitschwerdt, E. B. T2 - Kirk's current veterinary therapy : small animal practice (13th Ed.) PY - 2000/// SP - 302 PB - Philadelphia, PA : W.B. Saunders SN - 0721655238 ER - TY - CHAP TI - Why are infectious diseases emerging? AU - Breitschwerdt, E. B. AU - Dow, S. W. T2 - Kirk's current veterinary therapy : small animal practice (13th Ed.) PY - 2000/// SP - 244 PB - Philadelphia, PA : W.B. Saunders SN - 0721655238 ER - TY - JOUR TI - Urinary incontinence on dogs and cats. II. Diagnosis and treatment. A review / L'incontinenza urinaria nel cane e nel gatto. Parte II -- diagnosi e trattamento AU - Gookin, J. L. AU - Stone, E. A. AU - Sharp, N. J. T2 - Veterinaria DA - 2000/// PY - 2000/// VL - 14 IS - 2 SP - 43 ER - TY - JOUR TI - Urinary incontinence on dogs and cats. I. Measurement of urethral pressure. A review / L'incontinenza urinaria nel cane e nel gatto. Parte I -- profilometria della pressione uretrale AU - Gookin, J. L. AU - Stone, E. A. AU - Sharp, N. J. T2 - Veterinaria DA - 2000/// PY - 2000/// VL - 14 IS - 2 SP - 33 ER - TY - CHAP TI - The rickettsioses AU - Breitschwerdt, E. B. T2 - Textbook of veterinary internal medicine : diseases of the dog and cat (5th Ed.) PY - 2000/// SP - 400 PB - Philadelphia, PA : W.B. Saunders SN - 0721672566 ER - TY - JOUR TI - Responsiveness of diverse provenances of loblolly pine to fertilization - age 4 results AU - McKeand, Steven AU - Grissom, J. E. AU - Handest, J. A. AU - O'Malley, D. M. AU - Allen, H. L. T2 - Journal of Sustainable Forestry DA - 2000/// PY - 2000/// DO - 10.1300/j091v10n01_10 VL - 10 SP - 87–94 ER - TY - JOUR TI - Degenerative lumbosacral stenosis AU - De Risio, L AU - Thomas, WB AU - Sharp, NJH T2 - VETERINARY CLINICS OF NORTH AMERICA-SMALL ANIMAL PRACTICE AB - This article reviews the management of degenerative lumbosacral stenosis. Degenerative lumbosacral stenosis occurs when soft tissue and bony changes, possibly in conjunction with abnormal motion of the lumbosacral joint, impinge on the nerve roots or vasculature of the cauda equina. It occurs most frequently in middle-aged dogs of medium to large breed, especially the German Shepherd dog. Common signs are lumbosacral pain, lameness, pelvic limb weakness and ataxia, and urinary incontinence. Diagnosis is based on clinical features and imaging studies. Decompressive surgery is effective in most patients. DA - 2000/1// PY - 2000/1// DO - 10.1016/S0195-5616(00)50005-9 VL - 30 IS - 1 SP - 111-+ SN - 1878-1306 ER - TY - PAT TI - Solar cells incorporating light harvesting arrays AU - Lindsey, J. S. AU - Meyer, G. J. C2 - 2000/// DA - 2000/// PY - 2000/// ER - TY - PAT TI - Light harvesting arrays AU - Lindsey, J. S. C2 - 2000/// DA - 2000/// PY - 2000/// ER - TY - JOUR TI - Pines as model gymnosperms to study evolution, wood formation, and perennial growth AU - Lev-Yadun, S AU - Sederoff, R T2 - JOURNAL OF PLANT GROWTH REGULATION DA - 2000/9// PY - 2000/9// DO - 10.1007/s003440000045 VL - 19 IS - 3 SP - 290-305 SN - 1435-8107 KW - forest biotechnology KW - genomics KW - gymnosperms KW - Pinus KW - plant longevity KW - plant reproduction KW - wood formation KW - wood structure KW - xylogenesis ER - TY - JOUR TI - Nematode gene sequences, December 2000 update AU - McCarter, J.P. AU - Bird, D.McK. AU - Clifton, S.W. AU - Waterston, R.H. T2 - Journal of Nematology DA - 2000/// PY - 2000/// VL - 32 IS - 4 SP - 331-333 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0034353966&partnerID=MN8TOARS ER - TY - JOUR TI - The Danish Christmas industry: implications for the U.S. in production and marketing of real trees. AU - McKinley, C. R. AU - Frampton, L. J. T2 - Proceedings of the ... Society of American Foresters National Convention DA - 2000/// PY - 2000/// IS - 2000 SP - 175-179 ER - TY - JOUR TI - Rapid gene discovery in plant parasitic nematodes via Expressed Sequence Tags AU - McCarter, J AU - Abad, P AU - Jones, JT AU - Bird, D T2 - NEMATOLOGY AB - Abstract Projects currently underway are generating thousands of publicly available DNA sequences representing numerous genes from plant parasitic nematodes. Use of these data has the potential to revolutionise gene discovery, as well as aiding in genome physical mapping and expression profiling experiments. This article introduces sequences called expressed sequence tags or ESTs, which are single-sequence reads from randomly-selected cDNA clones. We review the process used to create these sequences and outline the strengths and weaknesses of ESTs as research tools. Instructions on how to access and use EST data also are provided. Découverte rapide de gènes chez les nématodes parasites des plantes: le point sur l'utilisation des Etiquettes de Séquences Exprimées - Les projets actuellement en cours génèrent des milliers de séquences d'ADN, publiquement disponibles, représentant de nombreux gènes de nématodes parasites des plantes. L'utilisation de ces données pourrait révolutionner la découverte des gènes en facilitant aussi bien les expériences de cartographie physique que celles de profils d'expression. Cet article présente les séquences dérivées de clones d'ADNc sélectionnés au hasard, appelées étiquettes de séquences exprimées (ESTs). Nous exposons le processus utilisé pour les générer de même que les avantages et les inconvénients des ESTs comme outils de recherche. Les instructions concernant l'accès et l'utilisation des ESTs sont également fournies. DA - 2000/// PY - 2000/// DO - 10.1163/156854100509574 VL - 2 IS - 7 SP - 719-731 SN - 1388-5545 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0034467290&partnerID=MN8TOARS KW - Caenorhabditis elegans KW - clustering KW - EST KW - Globodera KW - Meloidogyne KW - NemaGene ER - TY - JOUR TI - Plant parasitic nematodes: Habitats, hormones, and horizontally-acquired genes AU - Bird, D.M. AU - Koltai, H. T2 - Journal of Plant Growth Regulation DA - 2000/// PY - 2000/// VL - 19 IS - 2 SP - 183-194 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0033758702&partnerID=MN8TOARS ER - TY - JOUR TI - Persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous in transgenic line TgN3261Rpw AU - Colitz, CMH AU - Malarkey, DE AU - Woychik, RP AU - Wilkinson, JE T2 - VETERINARY PATHOLOGY AB - Persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous are congenital ocular anomalies that can lead to cataract formation. A line of insertional mutant mice, TgN3261Rpw, generated at the Oak Ridge National Laboratory in a large-scale insertional mutagenesis program was found to have a low incidence (8/243; 3.29%) of multiple developmental ocular abnormalities. The ocular abnormalities include persistent hyperplastic primary vitreous, persistent hyperplastic tunica vasculosa lentis, failure of cleavage of the anterior segment, retrolental fibrovascular membrane, posterior polar cataract, and detached retina. This transgenic mouse line provides an ontogenetic model because of the high degree of similarity of this entity in humans, dogs, and mice. DA - 2000/9// PY - 2000/9// DO - 10.1354/vp.37-5-422 VL - 37 IS - 5 SP - 422-427 SN - 0300-9858 KW - embryology KW - eye KW - mice KW - persistent hyperplastic primary vitreous KW - persistent hyperplastic tunica vasculosa lentis ER - TY - JOUR TI - Molecular approach toward information storage based on the redox properties of porphyrins in self-assembled monolayers AU - Roth, K. M. AU - Dontha, N. AU - Dabke, R. B. AU - Gryko, D. T. AU - Clausen, C. AU - Lindsey, J. S. AU - Bocian, D. F. AU - Kuhr, W. G. T2 - Journal of Vacuum Science & Technology. B, Microelectronics and Nanometer Structures DA - 2000/// PY - 2000/// VL - 18 IS - 5 SP - 2359-2364 ER - TY - JOUR TI - Discovery, purification, and characterization of a temperate transducing bacteriophage for Bordetella avium AU - Shelton, CB AU - Crosslin, DR AU - Casey, JL AU - Ng, S AU - Temple, LM AU - Orndorff, PE T2 - JOURNAL OF BACTERIOLOGY AB - ABSTRACT We discovered and characterized a temperate transducing bacteriophage (Ba1) for the avian respiratory pathogen Bordetella avium . Ba1 was initially identified along with one other phage (Ba2) following screening of four strains of B. avium for lysogeny. Of the two phage, only Ba1 showed the ability to transduce via an allelic replacement mechanism and was studied further. With regard to host range, Ba1 grew on six of nine clinical isolates of B. avium but failed to grow on any tested strains of Bordetella bronchiseptica , Bordetella hinzii , Bordetella pertussis , or Bordetella parapertussis . Ba1 was purified by CsCl gradient centrifugation and was found to have an icosahedral head that contained a linear genome of approximately 46.5 kb (contour length) of double-stranded DNA and a contractile, sheathed tail. Ba1 readily lysogenized our laboratory B. avium strain (197N), and the prophage state was stable for at least 25 generations in the absence of external infection. DNA hybridization studies indicated the prophage was integrated at a preferred site on both the host and phage replicons. Ba1 transduced five distinctly different insertion mutations, suggesting that transduction was generalized. Transduction frequencies ranged from approximately 2 × 10 −7 to 1 × 10 −8 transductants/PFU depending upon the marker being transduced. UV irradiation of transducing lysates markedly improved transduction frequency and reduced the number of transductants that were lysogenized during the transduction process. Ba1 may prove to be a useful genetic tool for studying B. avium virulence factors. DA - 2000/11// PY - 2000/11// DO - 10.1128/JB.182.21.6130-6136.2000 VL - 182 IS - 21 SP - 6130-6136 SN - 1098-5530 ER - TY - JOUR TI - The computed tomographic appearance of acute thoracolumbar intervertebral disc herniations in dogs AU - Olby, NJ AU - Munana, KR AU - Sharp, NJH AU - Thrall, DE T2 - VETERINARY RADIOLOGY & ULTRASOUND AB - The appearance of herniated intervertebral disc material in the thoracolumbar vertebral canal was evaluated in 23 dogs using computed tomography (CT). The images were then compared with the myelographic and surgical findings. The normal spinal cord, outlined by epidural fat over intervertebral disc spaces, was of intermediate attenuation on transverse CT images. Herniated disc material was identified in all animals as a heterogeneous hyperattenuating extradural mass. The attenuation of the disc material increased with the degree of mineralization. In seven dogs, the herniated material was only slightly more attenuating than the spinal cord. In these dogs, small fragments of mineralized disc material and significant hemorrhage were found in the epidural space at surgery. In dogs with a long standing history of disc herniations, disc material identified in the vertebral canal had a more hyperattenuating and homogeneous appearance than recently herniated disc material. We conclude that mineralized, herniated disc material and hemorrhage can be identified quickly and safely in dogs using CT. DA - 2000/// PY - 2000/// DO - 10.1111/j.1740-8261.2000.tb01860.x VL - 41 IS - 5 SP - 396-402 SN - 1740-8261 KW - intervertebral disc herniation KW - computed tomography KW - myelography KW - epidural hemorrhage KW - dog ER - TY - JOUR TI - Structural control of photoinduced energy transfer between adjacent and distant sites in multiporphyrin arrays AU - Lammi, RK AU - Ambroise, A AU - Balasubramanian, T AU - Wagner, RW AU - Bocian, DF AU - Holten, D AU - Lindsey, JS T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - A family of diphenylethyne-linked porphyrin dimers and trimers has been prepared via a building block approach for studies of energy-transfer processes. The dimers contain Mg and Zn porphyrins (MgZnU); the trimers contain an additional free base porphyrin (MgZnFbU). In both the dimers and trimers, sites of attachment to the Mg porphyrin (at the meso- or β-position) and diphenylethyne linker (at the para- or meta-positions) were varied, producing four Mg porphyrin−Zn porphyrin arrangements with the following linker configurations: meso-p/p-meso, meso-m/p-meso, β-p/p-meso, and β-m/p-meso. All four trimers employ a meso-p/p-meso Zn porphyrin−Fb porphyrin connection. The ground- and excited-state properties of the porphyrin dimers and trimers have been examined using static and time-resolved optical techniques. The rate of energy transfer from the photoexcited Zn porphyrin to the Mg porphyrin decreases according to the following trend: meso-p/p-meso (9 ps)-1 > β-p/p-meso (14 ps)-1 > meso-m/p-meso (19 ps)-1 > β-m/p-meso (27 ps)-1. In each compound, energy transfer between adjacent porphyrins occurs through a linker-mediated through-bond process. The rate of energy transfer between Zn and Fb porphyrins is constant in each trimer ((24 ps)-1). Energy transfer from the photoexcited Zn porphyrin branches to the adjacent Fb and Mg porphyrins, with nearly one-half to three-fourths proceeding to the Mg porphyrin (depending on the linker). Energy transfer from the excited Mg porphyrin to the nonadjacent Fb porphyrin occurs more slowly, with a rate that follows the same trend in linker architecture and porphyrin connection site: meso-p/p-meso (173 ps)-1 > β-p/p-meso (225 ps)-1 > meso-m/p-meso (320 ps)-1 > β-m/p-meso (385 ps)-1. The rate of transfer between nonadjacent Mg and Fb porphyrins does not change significantly with temperature, indicating a superexchange mechanism utilizing orbitals/states on the intervening Zn porphyrin. Energy transfer between nonadjacent sites may prove useful in directing energy flow in multiporphyrin arrays and related molecular photonic devices. DA - 2000/8/9/ PY - 2000/8/9/ DO - 10.1021/ja001031x VL - 122 IS - 31 SP - 7579-7591 SN - 0002-7863 ER - TY - JOUR TI - Regulation by homeoproteins: A comparison of deformed- responsive elements AU - Pederson, J. A. AU - LaFollette, J. W. AU - Gross, C. AU - Veraksa, A. AU - McGinnis, W. AU - Mahaffey, J. W. T2 - Genetics DA - 2000/// PY - 2000/// VL - 156 IS - 2 SP - 677-686 ER - TY - JOUR TI - Recombinant brassinosteroid insensitive 1 receptor-like kinase autophosphorylates on serine and threonine residues and phosphorylates a conserved peptide motif in vitro AU - Oh, MH AU - Ray, WK AU - Huber, SC AU - Asara, JM AU - Gage, DA AU - Clouse, SD T2 - PLANT PHYSIOLOGY AB - BRASSINOSTEROID-INSENSITIVE 1 (BRI1) encodes a putative Leucine-rich repeat receptor kinase in Arabidopsis that has been shown by genetic and molecular analysis to be a critical component of brassinosteroid signal transduction. In this study we examined some of the biochemical properties of the BRI1 kinase domain (BRI1-KD) in vitro, which might be important predictors of in vivo function. Recombinant BRI1-KD autophosphorylated on serine (Ser) and threonine (Thr) residues with p-Ser predominating. Matrix-assisted laser desorption/ionization mass spectrometry identified a minimum of 12 sites of autophosphorylation in the cytoplasmic domain of BRI1, including five in the juxtamembrane region (N-terminal to the catalytic KD), five in the KD (one each in sub-domains I and VIa and three in sub-domain VIII), and two in the carboxy terminal region. Five of the sites were uniquely identified (Ser-838, Thr-842, Thr-846, Ser-858, and Thr-872), whereas seven were localized on short peptides but remain ambiguous due to multiple Ser and/or Thr residues within these peptides. The inability of an active BRI1-KD to transphosphorylate an inactive mutant KD suggests that the mechanism of autophosphorylation is intramolecular. It is interesting that recombinant BRI1-KD was also found to phosphorylate certain synthetic peptides in vitro. To identify possible structural elements required for substrate recognition by BRI1-KD, a series of synthetic peptides were evaluated, indicating that optimum phosphorylation of the peptide required R or K residues at P - 3, P - 4, and P + 5 (relative to the phosphorylated Ser at P = 0). DA - 2000/10// PY - 2000/10// DO - 10.1104/pp.124.2.751 VL - 124 IS - 2 SP - 751-765 SN - 1532-2548 ER - TY - JOUR TI - Primary irradiation of canine intracranial masses AU - Spugnini, EP AU - Thrall, DE AU - Price, GS AU - Sharp, NJ AU - Munana, K AU - Page, RL T2 - VETERINARY RADIOLOGY & ULTRASOUND AB - Twenty‐nine dogs received primary radiation therapy for intracranial lesions and clinical signs suggestive of neoplasia. Presumptive diagnosis and tumor categorization was based on computed toniographic or magnetic resonance images. Meningioma was the most likely tumor type in 22 dogs and glioma or choroid plexus tumors were tentatively identified in 4 and 3 dogs, respectively. Cobalt‐60 radiation was delivered in 3 Gy fractions on a daily, Monday‐through‐Friday basis for a total dose of 48 Gy (16 fractions) in 28 dogs; one dog received 54 Gy. Two of 29 dogs died during treatment of signs suggestive of progressive tumor growth but were included in the overall evaluation of response to treatment. Median overall survival was 250 days (range 21–804). Mild acute radiation effects on normal tissue developed and did not influence outcome in any dog. Late radiation effects could not be evaluated in this study. No significant predictive indicators were identified from the clinical or imaging data. Radiation therapy is superior to medical treatment of brain tumors in dogs with steroids, is useful for tumors that are not currently operable and may be preferable to surgical resection in dogs if the mass appears infiltrative. However, 22/29 (76%) dogs died of recurrent progressive neuropathy suggestive of tumor regrowth or progression. Thus, alternative methods for delivery of radiation to dogs with brain tumors or novel combinations of therapy should continue to undergo evaluation. DA - 2000/// PY - 2000/// DO - 10.1111/j.1740-8261.2000.tb02091.x VL - 41 IS - 4 SP - 377-380 SN - 1740-8261 KW - dog KW - brain tumor KW - radiation therapy ER - TY - PAT TI - Methods for within family selection in woody perennials using genetic markers AU - O'Malley, D. M. AU - Sederoff, R. R. AU - Grattapaglia, D. C2 - 2000/// DA - 2000/// PY - 2000/// ER - TY - JOUR TI - High throughput cellular localization of specific plant mRNAs by liquid-phase in situ reverse transcription-polymerase chain reaction of tissue sections AU - Koltai, H AU - Bird, DM T2 - PLANT PHYSIOLOGY AB - Advances in high throughput DNA sequencing and bioinformatic gene discovery far outpace our ability to analyze gene function, necessitating development of more efficient means to examine expression at the cellular level. Here we present a polymerase chain reaction-based method to detect mRNA species in situ in which essentially all of the steps are carried out in liquid phase in a 96-well microtiter tray and only the final signal detection is performed on a microscope slide. We demonstrate the sensitivity of the method by the cellular localization of mRNA for the Tkn2 transcription factor in a wide variety of plant tissues, and its selectivity in discriminating a single gene family member by the in situ localization of rbcs3 transcripts. Furthermore, we demonstrate the utility of the in-well in situ method in detecting FDL and IFL1 transcripts in Arabidopsis sections, thus establishing the method as a tool to determine spatial expression pattern of sequences obtained from genomic sequencing projects. Being amenable to robotic processing, in-well in situ reverse transcription-polymerase chain reaction permits a great enhancement in the number of tissue samples that can be processed. Consequently, this method may become a powerful tool for functional genomics studies, permitting the cellular site of transcription of large numbers of sequences obtained from databases to be rapidly established. DA - 2000/8// PY - 2000/8// DO - 10.1104/pp.123.4.1203 VL - 123 IS - 4 SP - 1203-1212 SN - 0032-0889 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0033836945&partnerID=MN8TOARS ER - TY - JOUR TI - Heat shock protein HSP101 binds to the Fed-1 internal light regulatory element and mediates its high translational activity AU - Ling, J AU - Wells, DR AU - Tanguay, RL AU - Dickey, LF AU - Thompson, WF AU - Gallie, DR T2 - PLANT CELL AB - The internal light-regulatory element (iLRE) of ferredoxin (Fed-1) mRNA, comprising the 5' leader and at least the first 13 codons of the open reading frame, controls transcript abundance after illumination of the plant in a translation-dependent manner. We have characterized the RNA binding activities associated with the Fed-1 iLRE and have identified one activity as the heat shock protein HSP101, a protein shown to bind the 5' leader of tobacco mosaic virus. HSP101 was sufficient and necessary to mediate a high level of translational activity from a Fed-1 iLRE-containing mRNA in yeast. Moreover, the Fed-1 iLRE substantially enhanced translation of reporter mRNAs in plant protoplasts expressing HSP101. Expression of HSP101 was subject to developmental regulation in leaves in that expression was highest in young leaves. These data suggest that Fed-1 mRNA may use the HSP101 regulatory mechanism as a means of ensuring a high level of translation required for the light-mediated regulation of Fed-1 mRNA stability. DA - 2000/7// PY - 2000/7// DO - 10.1105/tpc.12.7.1213 VL - 12 IS - 7 SP - 1213-1227 SN - 1532-298X ER - TY - JOUR TI - Coyotes (Canis latrans) as the reservoir for a human pathogenic Bartonella sp.: Molecular epidemiology of Bartonella vinsonii subsp berkhoffii infection in coyotes from central coastal California AU - Chang, C. C. AU - Kasten, R. W. AU - Chomel, B. B. AU - Simpson, D. C. AU - Hew, C. M. AU - Kordick, D. L. AU - Heller, R. AU - Piemont, Y. AU - Breitschwerdt, E. B. T2 - Journal of Clinical Microbiology DA - 2000/// PY - 2000/// VL - 38 IS - 11 SP - 4193-4200 ER - TY - JOUR TI - A general mixture model approach for mapping quantitative trait loci from diverse cross designs involving multiple inbred lines AU - Liu, YF AU - Zeng, ZB T2 - GENETICAL RESEARCH AB - Most current statistical methods developed for mapping quantitative trait loci (QTL) based on inbred line designs apply to crosses from two inbred lines. Analysis of QTL in these crosses is restricted by the parental genetic differences between lines. Crosses from multiple inbred lines or multiple families are common in plant and animal breeding programmes, and can be used to increase the efficiency of a QTL mapping study. A general statistical method using mixture model procedures and the EM algorithm is developed for mapping QTL from various cross designs of multiple inbred lines. The general procedure features three cross design matrices, W , that define the contribution of parental lines to a particular cross and a genetic design matrix, D , that specifies the genetic model used in multiple line crosses. By appropriately specifying W matrices, the statistical method can be applied to various cross designs, such as diallel, factorial, cyclic, parallel or arbitrary-pattern cross designs with two or multiple parental lines. Also, with appropriate specification for the D matrix, the method can be used to analyse different kinds of cross populations, such as F 2 backcross, four-way cross and mixed crosses (e.g. combining backcross and F 2 ). Simulation studies were conducted to explore the properties of the method, and confirmed its applicability to diverse experimental designs. DA - 2000/6// PY - 2000/6// DO - 10.1017/S0016672300004493 VL - 75 IS - 3 SP - 345-355 SN - 0016-6723 ER - TY - JOUR TI - The Arabidopsis PHD-finger protein SHL is required for proper development and fertility AU - Mussig, C AU - Kauschmann, A AU - Clouse, SD AU - Altmann, T T2 - MOLECULAR AND GENERAL GENETICS DA - 2000/11// PY - 2000/11// DO - 10.1007/s004380000313 VL - 264 IS - 4 SP - 363-370 SN - 0026-8925 KW - PHD finger KW - BAH domain KW - transcription factor KW - nuclear localization KW - Arabidopsis ER - TY - JOUR TI - Rational synthesis of beta-substituted chlorin building blocks AU - Balasubramanian, T AU - Strachan, JP AU - Boyle, PD AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - Chlorins bearing synthetic handles at specific sites about the perimeter of the macrocycle constitute valuable building blocks. We previously developed methodology for preparing meso-substituted chlorin building blocks and now present methodology for preparing several complementary β-substituted chlorin building blocks. The chlorins bear one or two β substituents, one meso substituent, a geminal dimethyl group to lock in the chlorin hydrogenation level, and no flanking meso and β substituents. The synthesis involves convergent joining of an Eastern half and a Western half. New routes have been developed to two β-substituted bromo-dipyrromethane monocarbinols (Eastern halves). A new β-substituted Western half was prepared following the method for preparing an unsubstituted Western half (3,3-dimethyl-2,3-dihydrodipyrrin). Chlorin formation is achieved by a two-flask process of acid-catalyzed condensation followed by metal-mediated oxidative cyclization. β-Substituted chlorins have been prepared in 18−24% yield bearing a 4-iodophenyl group at the 8-position, a 4-iodophenyl group or a 4-[2-(trimethylsilyl)ethynyl]phenyl group at the 12-position, and a 4-iodophenyl group and a 4-[2-(trimethylsilyl)ethynyl]phenyl group at diametrically opposed β-positions (2, 12). The latter building block makes possible the stepwise construction of linear multi-chlorin architectures. The chlorins exhibit typical absorption and fluorescence spectra. A systematic shift in the absorption maximum (637−655 nm for the free base chlorins, 606−628 nm for the zinc chlorins) and intensity of the chlorin Qy band (ε up to 79 000 M-1 cm-1) is observed depending on the location of the substituents. The characteristic spectral features and location of substituents in defined positions make these chlorins well suited for a variety of applications in biomimetic and materials chemistry. DA - 2000/11/17/ PY - 2000/11/17/ DO - 10.1021/jo000913b VL - 65 IS - 23 SP - 7919-7929 SN - 0022-3263 ER - TY - JOUR TI - Evaluation of major genetic loci contributing to inbreeding depression for survival and early growth in a selfed family of Pinus taeda AU - Remington, D. L. AU - O'Malley, D. M. T2 - Evolution DA - 2000/// PY - 2000/// VL - 54 IS - 5 SP - 1580-1589 ER - TY - JOUR TI - A self-assembled light-harvesting array of seven porphyrins in a wheel and spoke architecture AU - Ambroise, A AU - Li, JZ AU - Yu, LH AU - Lindsey, JS T2 - ORGANIC LETTERS AB - [reaction: see text]A shape-persistent cyclic array of six zinc porphyrins provides an effective host for a dipyridyl-substituted free base porphyrin, yielding a self-assembled structure for studies of light harvesting. Energy transfer occurs essentially quantitatively from uncoordinated to pyridyl-coordinated zinc porphyrins in the cyclic array. Energy transfer from the coordinated zinc porphyrin to the guest free base porphyrin is less efficient (phitrans approximately 40%) and is attributed to a Förster through-space process. DA - 2000/8/24/ PY - 2000/8/24/ DO - 10.1021/ol006036d VL - 2 IS - 17 SP - 2563-2566 SN - 1523-7052 ER - TY - JOUR TI - A cytochrome P450 monooxygenase cDNA (CYP71A10) confers resistance to linuron in transgenic Nicotiana tabacum AU - Siminszky, B AU - Sheldon, BS AU - Corbin, FT AU - Dewey, RE T2 - WEED SCIENCE AB - The isolation of a Glycine max cytochrome P450 monooxygenase (P450) cDNA designated CYP71A10 that conferred linuron resistance to laboratory-grown, transgenic Nicotiana tabacum seedlings was previously reported. A nonsegregating transgenic N. tabacum line has been established that possesses two independent copies of the G. max CYP71A10 transgene. Five-week-old progeny plants of this selected line were grown in a controlled environmental chamber and treated with linuron using either pretransplant incorporated (PTI) or postemergence (POST) applications. CYP71A10-transformed N. tabacum was more tolerant to linuron than the wild type for both application methods. The transgenic N. tabacum line tolerated an approximately 16-fold and 12-fold higher rate of linuron than wild-type N. tabacum when the herbicide was applied PTI or POST, respectively. These results provide evidence that plant-derived P450 genes can be employed effectively to confer herbicide resistance to transgenic plants. DA - 2000/// PY - 2000/// DO - 10.1614/0043-1745(2000)048[0291:ACPMCC]2.0.CO;2 VL - 48 IS - 3 SP - 291-295 SN - 0043-1745 KW - cytochrome P450 KW - linuron KW - Glycine max L. Merr 'Dare', soybean KW - Nicotiana tabacum L. 'SR1', tobacco KW - herbicide metabolism KW - phenylurea KW - genetic engineering KW - metabolic engineering ER - TY - PAT TI - Isolated genes and proteins encoding resistance to photosensitizers AU - Daub, M. E. AU - Ehrenshaft, M. AU - Jenns, A. E. C2 - 2000/// DA - 2000/// PY - 2000/// ER - TY - PAT TI - Increasing expression of transgenes in plant cells using insulator elements AU - Thompson, W. AU - Allen, G. AU - Mankin, S. C2 - 2000/// DA - 2000/// PY - 2000/// ER - TY - JOUR TI - Genetic characterization of Escherichia coli type 1 pilus adhesin mutants and identification of a novel binding phenotype AU - Hamrick, TS AU - Harris, SL AU - Spears, PA AU - Havell, EA AU - Horton, , JR AU - Russell, PW AU - Orndorff, PE T2 - JOURNAL OF BACTERIOLOGY AB - ABSTRACT Five Escherichia coli type 1 pilus mutants that had point mutations in fimH , the gene encoding the type 1 pilus adhesin FimH, were characterized. FimH is a minor component of type 1 pili that is required for the pili to bind and agglutinate guinea pig erythrocytes in a mannose-inhibitable manner. Point mutations were located by DNA sequencing and deletion mapping. All mutations mapped within the signal sequence or in the first 28% of the predicted mature protein. All mutations were missense mutations except for one, a frameshift lesion that was predicted to cause the loss of approximately 60% of the mature FimH protein. Bacterial agglutination tests with polyclonal antiserum raised to a LacZ-FimH fusion protein failed to confirm that parental amounts of FimH cross-reacting material were expressed in four of the five mutants. The remaining mutant, a temperature-sensitive (ts) fimH mutant that agglutinated guinea pig erythrocytes after growth at 31°C but not at 42°C, reacted with antiserum at both temperatures in a manner similar to the parent. Consequently, this mutant was chosen for further study. Temperature shift experiments revealed that new FimH biosynthesis was required for the phenotypic change. Guinea pig erythrocyte and mouse macrophage binding experiments using the ts mutant grown at the restrictive and permissive temperatures revealed that whereas erythrocyte binding was reduced to a level comparable to that of a fimH insertion mutant at the restrictive temperature, mouse peritoneal macrophages were bound with parental efficiency at both the permissive and restrictive temperatures. Also, macrophage binding by the ts mutant was insensitive to mannose inhibition after growth at 42°C but sensitive after growth at 31°C. The ts mutant thus binds macrophages with one receptor specificity at 31°C and another at 42°C. DA - 2000/7// PY - 2000/7// DO - 10.1128/JB.182.14.4012-4021.2000 VL - 182 IS - 14 SP - 4012-4021 SN - 0021-9193 ER - TY - PAT TI - Cytochrome P-450 constructs and method of producing herbicide-resistant transgenic plants AU - Siminszky, B. AU - Dewey, R. AU - Corbin, F. C2 - 2000/// DA - 2000/// PY - 2000/// ER - TY - JOUR TI - Registration of NC97BGTAB9 and NC97BGTAB10 wheat germplasm lines resistant to powdery mildew AU - Navarro, R. A. AU - Murphy, J. P. AU - Leath, S. AU - Shi, A. T2 - Crop Science DA - 2000/// PY - 2000/// VL - 40 IS - 5 SP - 1508-1509 ER - TY - JOUR TI - Protective immunity against feline immunodeficiency virus induced by inoculation with vif-deleted proviral DNA AU - Lockridge, KM AU - Chien, M AU - Dean, GA AU - Cole, KS AU - Montelaro, RC AU - Luciw, PA AU - Sparger, EE T2 - VIROLOGY AB - To determine whether live-attenuated feline immunodeficiency virus (FIV) proviral DNA will induce protective immunity, a plasmid clone constructed with a FIV provirus containing a deletion in the viral accessory gene vif (FIV-pPPR-Deltavif) was inoculated as proviral DNA into four cats by the intramuscular route. After 43 weeks, these cats were boosted with the same proviral plasmid. Analysis of peripheral blood mononuclear cells at several time points after the primary and booster inoculations revealed no detectable virus or proviral DNA. At 6 weeks after the booster, immunized cats and additional naive control cats were challenged with a cell-free preparation of the infectious biological isolate FIV-PPR by the intraperitoneal route. Virus was detected after challenge in unvaccinated control cats but not in any of the FIV-pPPR-Deltavif-immunized cats. Both FIV Gag- and Env-specific cytotoxic T lymphocyte (CTL) activities were detected in peripheral blood cells of control cats after challenge infection, whereas only one of four cats immunized with FIV-pPPR-Deltavif DNA exhibited a measurable CTL response to Env following challenge. Although anti-Gag antibodies were not detected after both proviral DNA inoculation and challenge, anti-Env antibodies were found in FIV-pPPR-Deltavif-immunized cats after vaccination as well as after challenge. These findings indicate that inoculation with FIV-pPPR-Deltavif proviral DNA induced resistance to challenge with infectious FIV and that a vif deletion mutant may provide a relatively safe attenuated lentiviral vaccine. DA - 2000/7/20/ PY - 2000/7/20/ DO - 10.1006/viro.2000.0395 VL - 273 IS - 1 SP - 67-79 SN - 1089-862X ER - TY - JOUR TI - Geminiviruses: Models for plant DNA replication, transcription, and cell cycle regulation AU - Hanley-Bowdoin, L. AU - Settlage, S. B. AU - Orozco, B. M. AU - Nagar, S. AU - Robertson, D. T2 - Critical Reviews in Biochemistry and Molecular Biology DA - 2000/// PY - 2000/// VL - 35 IS - 2 SP - 105-140 ER - TY - JOUR TI - Chromosome condensation induced by geminivirus infection of mature plant cells AU - Bass, H. W. AU - Nagar, S. AU - Hanley-Bowdoin, L. AU - Robertson, D. T2 - Journal of Cell Science DA - 2000/// PY - 2000/// VL - 113 IS - 7 SP - 1149-1160 ER - TY - JOUR TI - Calcium-regulated proteolysis of eEF1A AU - Ransom-Hodgkins, WD AU - Brglez, I AU - Wang, XM AU - Boss, WF T2 - PLANT PHYSIOLOGY AB - Abstract Eukaryotic elongation factor 1α (eEF1A) can be post-translationally modified by the addition of phosphorylglycerylethanolamine (PGE). [14C]Ethanolamine was incorporated into the PGE modification, and with carrot (Daucus carota L.) suspension culture cells, eEF1A was the only protein that incorporated detectable quantities of [14C]ethanolamine (Ransom et al., 1998). When 1 mm CaCl2 was added to microsomes containing [14C]ethanolamine-labeled eEF1A ([14C]et-eEF1A), there was a 60% decrease in the amount of [14C]et-eEF1A recovered after 10 min. The loss of endogenous [14C]et-eEF1A was prevented by adding EGTA. Recombinant eEF1A, which did not contain the PGE modification, also was degraded by microsomes in a Ca2+-regulated manner, indicating that PGE modification was not necessary for proteolysis; however, it enabled us to quantify enodgenous eEF1A. By monitoring [14C]et-eEF1A, we found that treatment with phospholipase D or C, but not phospholipase A2, resulted in a decrease in [14C]et-eEF1A from carrot microsomes. The fact that there was no loss of [14C]et-eEF1A with phospholipase A2 treatment even in the presence of 1 mmCa2+ suggested that the loss of membrane lipids was not essential for eEF1A proteolysis and that lysolipids or fatty acids decreased proteolysis. At micromolar Ca2+ concentrations, proteolysis of eEF1A was pH sensitive. When 1 μmCaCl2 was added at pH 7.2, 35% of [14C]et-eEF1A was lost; while at pH 6.8, 10 μm CaCl2 was required to give a similar loss of protein. These data suggest that eEF1A may be an important downstream target for Ca2+ and lipid-mediated signal transduction cascades. DA - 2000/3// PY - 2000/3// DO - 10.1104/pp.122.3.957 VL - 122 IS - 3 SP - 957-965 SN - 0032-0889 ER - TY - JOUR TI - Bartonella Infection in Animals: Carriership, Reservoir Potential, Pathogenicity, and Zoonotic Potential for Human Infection AU - Breitschwerdt, Edward B. AU - Kordick, Dorsey L. T2 - Clinical Microbiology Reviews AB - Recent observations have begun to support a role for Bartonella spp. as animal as well as human pathogens. Bartonella spp. are vector-transmitted, blood-borne, intracellular, gram-negative bacteria that can induce prolonged infection in the host. Persistent infections in domestic and wild animals result in a substantial reservoir of Bartonella organisms in nature that can serve as a source for inadvertent human infection. The prevalence of bacteremia can range from 50 to 95% in selected rodent, cat, deer, and cattle populations. Dogs infected with Bartonella spp. can develop lameness, endocarditis, granulomatous lymphadenitis, and peliosis hepatis, lesions that have also been reported in association with human infection. Understanding the role of Bartonella spp. as pathogens in cats and other wild or domestic animals awaits the results of additional studies. Considering the extensive animal reservoirs and the large number of insects that have been implicated in the transmission of Bartonella spp., both animal and human exposure to these organisms may be more substantial than is currently believed. DA - 2000/7/1/ PY - 2000/7/1/ DO - 10.1128/CMR.13.3.428-438.2000 VL - 13 IS - 3 SP - 428-438 J2 - Clin. Microbiol. Rev. LA - en OP - SN - 0893-8512 1098-6618 UR - http://dx.doi.org/10.1128/CMR.13.3.428 DB - Crossref ER - TY - JOUR TI - A tightly coupled linear array of perylene, bis(porphyrin), and phthalocyanine units that functions as a photoinduced energy-transfer cascade AU - Miller, MA AU - Lammi, RK AU - Prathapan, S AU - Holten, D AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - We have prepared a linear array of chromophores consisting of a perylene input unit, a bis(free base porphyrin) transmission unit, and a free base phthalocyanine output unit for studies in artificial photosynthesis and molecular photonics. The synthesis involved four stages: (1) a rational synthesis of trans-AB2C-porphyrin building blocks each bearing one meso-unsubstituted position, (2) oxidative, meso,meso coupling of the zinc porphyrin monomers to afford a bis(zinc porphyrin) bearing one phthalonitrile group and one iodophenyl group, (3) preparation of a bis(porphyrin)−phthalocyanine array via a mixed cyclization involving the bis(free base porphyrin) and 4-tert-butylphthalonitrile, and (4) Pd-mediated coupling of an ethynylperylene to afford a perylene−bis(porphyrin)−phthalocyanine linear array. The perylene−bis(porphyrin)−phthalocyanine array absorbs strongly across the visible spectrum. Excitation at 490 nm, where the perylene absorbs preferentially, results in fluorescence almost exclusively from the phthalocyanine (Φf = 0.78). The excited phthalocyanine forms with time constants of 2 ps (90%) and 13 ps (10%). The observed time constants resemble those of corresponding phenylethyne-linked dyads, including a perylene−porphyrin (≤0.5 ps) and a porphyrin−phthalocyanine (1.1 ps (70%) and 8 ps (30%)). The perylene−bis(porphyrin)−phthalocyanine architecture exhibits efficient light-harvesting properties and rapid funneling of energy in a cascade from perylene to bis(porphyrin) to phthalocyanine. DA - 2000/10/6/ PY - 2000/10/6/ DO - 10.1021/jo0007940 VL - 65 IS - 20 SP - 6634-6649 SN - 1520-6904 ER - TY - JOUR TI - A geminivirus replication protein interacts with the retinoblastoma protein through a novel domain to determine symptoms and tissue specificity of infection in plants AU - Kong, LJ AU - Orozco, BM AU - Roe, JL AU - Nagar, S AU - Ou, S AU - Feiler, HS AU - Durfee, T AU - Miller, AB AU - Gruissem, W AU - Robertson, D AU - Hanley-Bowdoin, L T2 - EMBO JOURNAL AB - Geminiviruses replicate in nuclei of mature plant cells after inducing the accumulation of host DNA replication machinery. Earlier studies showed that the viral replication factor, AL1, is sufficient for host induction and interacts with the cell cycle regulator, retinoblastoma (pRb). Unlike other DNA virus proteins, AL1 does not contain the pRb binding consensus, LXCXE, and interacts with plant pRb homo logues (pRBR) through a novel amino acid sequence. We mapped the pRBR binding domain of AL1 between amino acids 101 and 180 and identified two mutants that are differentially impacted for AL1-pRBR interactions. Plants infected with the E-N140 mutant, which is wild-type for pRBR binding, developed wild-type symptoms and accumulated viral DNA and AL1 protein in epidermal, mesophyll and vascular cells of mature leaves. Plants inoculated with the KEE146 mutant, which retains 16% pRBR binding activity, only developed chlorosis along the veins, and viral DNA, AL1 protein and the host DNA synthesis factor, proliferating cell nuclear antigen, were localized to vascular tissue. These results established the importance of AL1-pRBR interactions during geminivirus infection of plants. DA - 2000/7/3/ PY - 2000/7/3/ DO - 10.1093/emboj/19.13.3485 VL - 19 IS - 13 SP - 3485-3495 SN - 0261-4189 KW - AL1 KW - cell cycle KW - differentiation KW - plant DNA virus KW - pRb ER - TY - JOUR TI - The surface conformation of sindbis virus glycoproteins E1 and E2 at neutral and low pH, as determined by mass spectrometry-based mapping AU - Phinney, BS AU - Blackburn, K AU - Brown, DT T2 - JOURNAL OF VIROLOGY AB - Sindbis virus contains two membrane glycoproteins, E1 and E2, which are organized into 80 trimers of heterodimers (spikes). These trimers form a precise T=4 icosahedral protein lattice on the surface of the virus. Very little is known about the organization of the E1 and E2 glycoproteins within the spike trimer. To gain a better understanding of how the proteins E1 and E2 are arranged in the virus membrane, we have used the techniques of limited proteolysis and amino acid chemical modification in combination with mass spectrometry. We have determined that at neutral pH the E1 protein regions that are accessible to proteases include domains 1-21 (region encompassing amino acids 1 to 21), 161-176, and 212-220, while the E2 regions that are accessible include domains 31-84, 134-148, 158-186, 231-260, 299-314, and 324-337. When Sindbis virus is exposed to low pH, E2 amino acid domains 99-102 and 262-309 became exposed while other domains became inaccessible. Many new E1 regions became accessible after exposure to low pH, including region 86-91, which is in the putative fusion domain of E1 of Semliki Forest virus (SFV) (M. C. Kielian et al., J. Cell Biol. 134:863-872, 1996). E1 273-287 and region 145-158 were also exposed at low pH. These data support a model for the structure of the alphavirus spike in which the E1 glycoproteins are centrally located as trimers which are surrounded and protected by the E2 glycoprotein. These data improve our understanding of the structure of the virus membrane and have implications for understanding the protein conformational changes which accompany the process of virus-cell membrane fusion. DA - 2000/6// PY - 2000/6// DO - 10.1128/JVI.74.12.5667-5678.2000 VL - 74 IS - 12 SP - 5667-5678 SN - 0022-538X ER - TY - JOUR TI - The photoactivated Cercospora toxin cercosporin: Contributions to plant disease and fundamental biology AU - Daub, ME AU - Ehrenshaft, M T2 - ANNUAL REVIEW OF PHYTOPATHOLOGY AB - Plant pathogenic fungi in eight genera produce light-activated perylenequinone toxins that are toxic to plants via the generation of activated oxygen species, particularly singlet oxygen. Studies on the cercosporin toxin produced by Cercospora species have documented an important role for this toxin in pathogenesis of host plants. Cercosporin-generated active oxygen species destroy the membranes of host plants, providing nutrients to support the growth of these intercellular pathogens. Resistance of Cercospora species to the toxic effects of their own toxin has allowed these organisms to be used as a model for understanding the cellular basis of resistance to singlet oxygen and to general oxidative stress. In particular, the recent discovery that pyridoxine (vitamin B6) quenches singlet oxygen has led to the understanding of a novel role for this vitamin in cells as well as the discovery of a novel pathway of biosynthesis. DA - 2000/// PY - 2000/// DO - 10.1146/annurev.phyto.38.1.461 VL - 38 SP - 461-+ SN - 1545-2107 KW - active oxygen KW - singlet oxygen KW - photosensitization KW - polyketide KW - fungal toxins ER - TY - JOUR TI - The molecular population genetics of regulatory genes AU - Purugganan, MD T2 - MOLECULAR ECOLOGY AB - Regulatory loci, which may encode both trans acting proteins as well as cis acting promoter regions, are crucial components of an organism's genetic architecture. Although evolution of these regulatory loci is believed to underlie the evolution of numerous adaptive traits, there is little information on natural variation of these genes. Recent molecular population genetic studies, however, have provided insights into the extent of natural variation at regulatory genes, the evolutionary forces that shape them and the phenotypic effects of molecular regulatory variants. These recent analyses suggest that it may be possible to study the molecular evolutionary ecology of regulatory diversification by examining both the extent and patterning of regulatory gene diversity, the phenotypic effects of molecular variation at these loci and their ecological consequences. DA - 2000/10// PY - 2000/10// DO - 10.1046/j.1365-294x.2000.01016.x VL - 9 IS - 10 SP - 1451-1461 SN - 1365-294X KW - evolution of development KW - phenotypic variation KW - polymorphism KW - promoters KW - QTL KW - transcriptional activators ER - TY - JOUR TI - Synthesis of thiol-derivatized porphyrin dimers and trimers for studies of architectural effects on multibit information storage AU - Clausen, C AU - Gryko, DT AU - Dabke, RB AU - Dontha, N AU - Bocian, DF AU - Kuhr, WG AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - We present the rational design and synthesis of multiporphyrin arrays containing thiol-derivatized linkers for the purpose of multibit molecular information storage. Porphyrin dimers and trimers were synthesized by the Pd-mediated coupling of iodo-substituted and ethynyl-substituted porphyrin building blocks in 5−51% yields. Each porphyrin dimer bears one S-acetylthio group. The architecture of the trimers incorporates a trans-substituted porphyrin (central) bearing two S-acetylthio groups and two diphenylethyne-linked porphyrins (wings) in a trans geometry. The central porphyrin and the wing porphyrins bear distinct substituents and central metals, thereby affording different oxidation potentials. The S-acetylthio groups provide a means for attachment of the arrays to an electroactive surface. The dimers are designed for vertical orientation on an electroactive surface while the trimers are designed for horizontal orientation of the central porphyrin. Altogether seven different arrays were synthesized. Each array forms a self-assembled monolayer (SAM) on gold via in situ cleavage of the S-acetyl protecting group. The SAM of each array is electrochemically robust and exhibits multiple, reversible oxidation waves. In general, however, the trimeric arrays appear to form more highly ordered monolayers that exhibit sharper, better-defined redox features. DA - 2000/11/3/ PY - 2000/11/3/ DO - 10.1021/jo000488m VL - 65 IS - 22 SP - 7363-7370 SN - 0022-3263 ER - TY - JOUR TI - Synthesis of thiol-derivatized ferrocene-porphyrins for studies of multibit information storage AU - Gryko, DT AU - Zhao, F AU - Yasseri, AA AU - Roth, KM AU - Bocian, DF AU - Kuhr, WG AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - One approach toward storage of multiple bits of information at the molecular level requires the construction of molecular architectures comprised of multiple redox-active units. Four new ferrocene-porphyrins have been synthesized to investigate questions concerning (1) the scope of redox-active molecules that can be employed in molecular information-storage schemes and (2) writing/reading rates as well as retention of charge in redox-active units located at different sites in a molecular architecture. Three of the ferrocene-porphyrins have linkers of different lengths between the ferrocene and porphyrin. The fourth ferrocene-porphyrin has two ferrocenes positioned at the lateral sites on the porphyrin. The latter architecture is designed to provide a shorter distance between the electroactive surface and the ferrocene while maintaining an upright orientation of the porphyrin. Each ferrocene-porphyrin affords three cationic oxidation states (ferrocene monocation, porphyrin monocation, porphyrin dication) in addition to the neutral state, thereby affording the capability of storing two bits of information. Each ferrocene-porphyrin bears an S-acetyl or S-(N-ethyl)carbamoyl-protected thiol moiety, thereby avoiding handling of free thiols. Each ferrocene-porphyrin forms a self-assembled monolayer (SAM) on gold via in situ cleavage of the thiol protecting group. The SAM of each array is electrochemically robust and exhibits three well-resolved, reversible oxidation waves. DA - 2000/11/3/ PY - 2000/11/3/ DO - 10.1021/jo0004862 VL - 65 IS - 22 SP - 7356-7362 SN - 0022-3263 ER - TY - JOUR TI - Synthesis of thiol-derivatized europium porphyrinic triple-decker sandwich complexes for multibit molecular information storage AU - Li, JZ AU - Gryko, D AU - Dabke, RB AU - Diers, , JR AU - Bocian, DF AU - Kuhr, WG AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - The storage of multiple bits of information at the molecular level requires molecules with a large number of distinct oxidation states. Lanthanide triple-decker sandwich molecules employing porphyrins and phthalocyanines afford four cationic states and are very attractive for molecular information storage applications. Five triple-decker building blocks have been prepared of the type (phthalocyanine)Eu(phthalocyanine)Eu(porphyrin), each bearing one iodo, one ethyne, or one iodo and one ethyne group attached to the porphyrin unit. Two triple-decker building blocks with different oxidation potentials were derivatized with an S-acetylthiophenyl unit for attachment to an electroactive surface. To explore the preparation of arrays comprised of triple deckers, which may lead to the storage of a larger number of bits, two types of dyads of triple deckers were prepared. An ethyne-linked dyad of triple deckers bearing one S-acetylthiophenyl unit was prepared via repetitive Sonogashira couplings, and a butadiyne-linked dyad was prepared via a modified Glaser coupling. The triple deckers were characterized by absorption spectroscopy, laser-desorption mass spectrometry, and (1)H NMR spectroscopy. The thiol-derivatized triple deckers form self-assembled monolayers (SAMs) on gold via in situ cleavage of the thiol protecting group. The SAM of each array is electrochemically robust and exhibits three well-resolved, reversible oxidation waves. These electrochemical characteristics indicate that these types of molecules are well suited for storing multiple bits of information. DA - 2000/11/3/ PY - 2000/11/3/ DO - 10.1021/jo000490d VL - 65 IS - 22 SP - 7379-7390 SN - 0022-3263 ER - TY - JOUR TI - Synthesis of "porphyrin-linker-thiol" molecules with diverse linkers for studies of molecular-based information storage AU - Gryko, DT AU - Clausen, C AU - Roth, KM AU - Dontha, N AU - Bocian, DF AU - Kuhr, WG AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - The attachment of redox-active molecules such as porphyrins to an electroactive surface provides an attractive approach for electrically addressable molecular-based information storage. Porphyrins are readily attached to a gold surface via thiol linkers. The rate of electron transfer between the electroactive surface and the porphyrin is one of the key factors that dictates suitability for molecular-based memory storage. This rate depends on the type and length of the linker connecting the thiol unit to the porphyrin. We have developed different routes for the preparation of thiol-derivatized porphyrins with eight different linkers. Two sets of linkers explore the effects of linker length and conjugation, with one set comprising phenylethyne units and one set comprising alkyl units. One electron-deficient linker has four fluorine atoms attached directly to a thiophenyl unit. To facilitate the synthesis of the porphyrins, convenient routes have been developed to a wide range of aldehydes possessing a protected S-acetylthio group. An efficient synthesis of 1-(S-acetylthio)-4-iodobenzene also has been developed. A set of porphyrins, each bearing one S-acetyl-derivatized linker at one meso position and mesityl moieties at the three remaining meso positions, has been synthesized. Altogether seven new aldehydes, eight free base porphyrins and eight zinc porphyrins have been prepared. The zinc porphyrins bearing the different linkers all form self-assembled monolayers (SAMs) on gold via in situ cleavage of the S-acetyl protecting group. The SAM of each porphyrin is electrochemically robust and exhibits two reversible oxidation waves. DA - 2000/11/3/ PY - 2000/11/3/ DO - 10.1021/jo000487u VL - 65 IS - 22 SP - 7345-7355 SN - 0022-3263 ER - TY - JOUR TI - Subtilisins of Bacillus spp. hydrolyze keratin and allow growth on feathers AU - Evans, KL AU - Crowder, J AU - Miller, ES T2 - CANADIAN JOURNAL OF MICROBIOLOGY DA - 2000/11// PY - 2000/11// DO - 10.1139/cjm-46-11-1004 VL - 46 IS - 11 SP - 1004-1011 SN - 0008-4166 KW - keratin hydrolysis KW - Bacillus KW - subtilisin KW - keratinase ER - TY - JOUR TI - Substrate specificity of a maize ribosome-inactivating protein differs across diverse taxa AU - Krawetz, J. E. AU - Boston, R. S. T2 - European Journal of Biochemistry AB - The superfamily of ribosome-inactivating proteins (RIPs) consists of toxins that catalytically inactivate ribosomes at a universally conserved region of the large ribosomal RNA. RIPs carry out a single N-glycosidation event that alters the binding site of the translational elongational factor eEF1A and causes a cessation of protein synthesis that leads to subsequent cell death. Maize RIP1 is a kernel-specific RIP with the unusual property of being produced as a zymogen, proRIP1. ProRIP1 accumulates during seed development and becomes active during germination when cellular proteases remove acidic residues from a central domain and both termini. These deletions also result in RIP activation in vitro. However, the effectiveness of RIP1 activity against target ribosomes remains species-dependent. To determine the potential efficiency of maize RIP1 as a plant defense protein, we used quantitative RNA gel blots to detect products of RIP activity against intact ribosomal substrates from various species. We determined the enzyme specificity of recombinant maize proRIP1 (rproRIP1), papain-activated rproRIP1 and MOD1 (an active deletion mutant of rproRIP1) against ribosomal substrates with differing levels of RIP sensitivity. The rproRIP1 had no detectable enzymatic activity against ribosomes from any of the species assayed. The papain-activated rproRIP1 was more active than MOD1 against ribosomes from either rabbit or the corn pathogen, Aspergillus flavus, but the difference was much more marked when rabbit ribosomes were used as a substrate. The papain-activated rproRIP1 was much more active against rabbit ribosomes than homologous Zea mays ribosomes and had no detectable effect on Escherichia coli ribosomes. DA - 2000/// PY - 2000/// DO - 10.1046/j.1432-1327.2000.01200.x VL - 267 IS - 7 SP - 1966-1974 ER - TY - JOUR TI - Sindbis virus glycoprotein E1 is divided into two discrete domains at amino acid 129 by disulfide bridge connections AU - Phinney, BS AU - Brown, DT T2 - JOURNAL OF VIROLOGY AB - The E1 membrane glycoprotein of Sindbis virus contains structural and functional domains, which are conformationally dependent on the presence of intramolecular disulfide bridges (B. A. Abell and D. T. Brown, J. Virol. 67:5496-5501, 1993; R. P. Anthony, A. M. Paredes, and D. T. Brown, Virology 190:330-336, 1992). We have examined the disulfide bonds in E1 and have determined that the E1 membrane glycoprotein contains two separate sets of interconnecting disulfide linkages, which divide the protein into two domains at amino acid 129. These separate sets of disulfides may stabilize and define the structural and functional regions of the E1 protein. DA - 2000/10// PY - 2000/10// DO - 10.1128/JVI.74.19.9313-9316.2000 VL - 74 IS - 19 SP - 9313-9316 SN - 0022-538X ER - TY - JOUR TI - Separation of phylogenetic and functional associations in biological sequences by using the parametric bootstrap AU - Wollenberg, KR AU - Atchley, WR T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - Quantitative analyses of biological sequences generally proceed under the assumption that individual DNA or protein sequence elements vary independently. However, this assumption is not biologically realistic because sequence elements often vary in a concerted manner resulting from common ancestry and structural or functional constraints. We calculated intersite associations among aligned protein sequences by using mutual information. To discriminate associations resulting from common ancestry from those resulting from structural or functional constraints, we used a parametric bootstrap algorithm to construct replicate data sets. These data are expected to have intersite associations resulting solely from phylogeny. By comparing the distribution of our association statistic for the replicate data against that calculated for empirical data, we were able to assign a probability that two sites covaried resulting from structural or functional constraint rather than phylogeny. We tested our method by using an alignment of 237 basic helix–loop–helix (bHLH) protein domains. Comparison of our results against a solved three-dimensional structure confirmed the identification of several sites important to function and structure of the bHLH domain. This analytical procedure has broad utility as a first step in the identification of sites that are important to biological macromolecular structure and function when a solved structure is unavailable. Sign up for PNAS alerts. Get alerts for new articles, or get an alert when an article is cited. Manage alerts DA - 2000/3/28/ PY - 2000/3/28/ DO - 10.1073/pnas.070154797 VL - 97 IS - 7 SP - 3288-3291 SN - 0027-8424 ER - TY - JOUR TI - Semiparametric regression for periodic longitudinal hormone data from multiple menstrual cycles AU - Zhang, DW AU - Lin, XH AU - Sowers, MF T2 - BIOMETRICS AB - We consider semiparametric regression for periodic longitudinal data. Parametric fixed effects are used to model the covariate effects and a periodic nonparametric smooth function is used to model the time effect. The within-subject correlation is modeled using subject-specific random effects and a random stochastic process with a periodic variance function. We use maximum penalized likelihood to estimate the regression coefficients and the periodic nonparametric time function, whose estimator is shown to be a periodic cubic smoothing spline. We use restricted maximum likelihood to simultaneously estimate the smoothing parameter and the variance components. We show that all model parameters can be easily obtained by fitting a linear mixed model. A common problem in the analysis of longitudinal data is to compare the time profiles of two groups, e.g., between treatment and placebo. We develop a scaled chi-squared test for the equality of two nonparametric time functions. The proposed model and the test are illustrated by analyzing hormone data collected during two consecutive menstrual cycles and their performance is evaluated through simulations. DA - 2000/3// PY - 2000/3// DO - 10.1111/j.0006-341X.2000.00031.x VL - 56 IS - 1 SP - 31-39 SN - 0006-341X KW - nonparametric regression KW - penalized likelihood KW - periodic smoothing spline KW - restricted maximum likelihood KW - test for equality of functions ER - TY - JOUR TI - Rational syntheses of porphyrins bearing up to four different meso substituents AU - Rao, PD AU - Dhanalekshmi, S AU - Littler, BJ AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - Porphyrins bearing specific patterns of substituents are crucial building blocks in biomimetic and materials chemistry. We have developed methodology that avoids statistical reactions, employs minimal chromatography, and affords up to gram quantities of regioisomerically pure porphyrins bearing predesignated patterns of up to four different meso substituents. The methodology is based upon the availability of multigram quantities of dipyrromethanes. A procedure for the diacylation of dipyrromethanes using EtMgBr and an acid chloride has been refined. A new procedure for the preparation of unsymmetrical diacyl dipyrromethanes has been developed that involves (1) monoacylation with EtMgBr and a pyridyl benzothioate followed by (2) introduction of the second acyl unit upon reaction with EtMgBr and an acid chloride. The scope of these acylation methods has been examined by preparing multigram quantities of diacyl dipyrromethanes bearing a variety of substituents. Reduction of the diacyl dipyrromethane to the corresponding dipyrromethane-dicarbinol is achieved with NaBH(4) in methanolic THF. Porphyrin formation involves the acid-catalyzed condensation of a dipyrromethane-dicarbinol and a dipyrromethane followed by oxidation with DDQ. Optimal conditions for the condensation were identified after examining various reaction parameters (solvent, temperature, acid, concentration, time). The conditions identified (2.5 mM reactants in acetonitrile containing 30 mM TFA at room temperature for <7 min) provided reaction without detectable scrambling (LD-MS) for aryl-substituted dipyrromethanes, and trace scrambling for alkyl-substituted dipyrromethanes. The desired porphyrins were obtained in 14-40% yield. The synthesis is compatible with diverse functionalities: amide, aldehyde, carboxylic acid, ester, nitrile, ether, bromo, iodo, ethyne, TMS-ethyne, TIPS-ethyne, perfluoroarene. In total 30 porphyrins of the types A(3)B, trans-A(2)B(2), trans-AB(2)C, cis-A(2)B(2), cis-A(2)BC, and ABCD were prepared, including >1-g quantities of three porphyrins. DA - 2000/11/3/ PY - 2000/11/3/ DO - 10.1021/jo000882k VL - 65 IS - 22 SP - 7323-7344 SN - 0022-3263 ER - TY - JOUR TI - Protein recycling from the Golgi apparatus to the endoplasmic reticulum in plants and its minor contribution to calreticulin retention AU - Pagny, S AU - Cabanes-Macheteau, M AU - Gillikin, JW AU - Leborgne-Castel, N AU - Lerouge, P AU - Boston, RS AU - Faye, L AU - Gomord, V T2 - PLANT CELL AB - Using pulse-chase experiments combined with immunoprecipitation and N-glycan structural analysis, we showed that the retrieval mechanism of proteins from post-endoplasmic reticulum (post-ER) compartments is active in plant cells at levels similar to those described previously for animal cells. For instance, recycling from the Golgi apparatus back to the ER is sufficient to block the secretion of as much as 90% of an extracellular protein such as the cell wall invertase fused with an HDEL C-terminal tetrapeptide. Likewise, recycling can sustain fast retrograde transport of Golgi enzymes into the ER in the presence of brefeldin A. However, on the basis of our data, we propose that this retrieval mechanism in plants has little impact on the ER retention of a soluble ER protein such as calreticulin. Indeed, the latter is retained in the ER without any N-glycan-related evidence for a recycling through the Golgi apparatus. Taken together, these results indicate that calreticulin and perhaps other plant reticuloplasmins are possibly largely excluded from vesicles exported from the ER. Instead, they are probably retained in the ER by mechanisms that rely primarily on signals other than H/KDEL motifs. DA - 2000/5// PY - 2000/5// DO - 10.1105/tpc.12.5.739 VL - 12 IS - 5 SP - 739-755 SN - 1531-298X ER - TY - JOUR TI - New frontiers in the study of dispersal and spatial analysis of epidemics caused by species in the genus Phytophthora AU - Ristaino, JB AU - Gumpertz, ML T2 - ANNUAL REVIEW OF PHYTOPATHOLOGY AB - Diseases caused by species in the genus Phytophthora are responsible for significant economic losses on a wide range of host plants. Spatial pattern is one of the most characteristic ecological properties of a species, and reflects environmental and genetic heterogeneity and reproductive population growth acting on the processes of reproduction, dispersal, and mortality. Species of Phytophthora can be dispersed either in soil, via surface water movement down rows, from rain splash dispersal, by air, or via movement by humans or invertebrate activity. Dispersal results in patchiness in patterns of disease or inoculum in soil. In this chapter we discuss the mechanisms of dispersal of members of this important genus and describe several methods that can be used to statistically analyze data for which spatial coordinates are known. The methods include testing spatial autocorrelation for binary data or continuous data, semivariograms, and regression models for spatial data. The goal of spatial pattern analysis is to gain an understanding of the mechanisms of dispersal of propagules and to sort out the physical and biological factors that are important for spread of plant pathogens and ultimately, for disease management. DA - 2000/// PY - 2000/// DO - 10.1146/annurev.phyto.38.1.541 VL - 38 IS - 2000 SP - 541-+ SN - 1545-2107 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0033748429&partnerID=MN8TOARS KW - dispersal KW - epidemiology KW - management KW - molecular epidemiology KW - spatial pattern analysis KW - Phytophthora diseases ER - TY - JOUR TI - Molecular evolution of flower development AU - Lawton-Rauh, AL AU - Alvarez-Buylla, ER AU - Purugganan, MD T2 - TRENDS IN ECOLOGY & EVOLUTION AB - Flowers, as reproductive structures of the most successful group of land plants, have been a central focus of study for both evolutionists and ecologists. Recent advances in unravelling the genetics of flower development have provided insight into the evolution of floral structures among angiosperms. The study of the evolution of genes that control floral morphogenesis permits us to draw inferences on the diversification of developmental systems, the origin of floral organs and the selective forces that drive evolutionary change among these plant reproductive structures. DA - 2000/4// PY - 2000/4// DO - 10.1016/S0169-5347(99)01816-9 VL - 15 IS - 4 SP - 144-149 SN - 0169-5347 ER - TY - JOUR TI - Investigation of tightly coupled porphyrin arrays comprised of identical monomers for multibit information storage AU - Clausen, C AU - Gryko, DT AU - Yasseri, AA AU - Diers, , JR AU - Bocian, DF AU - Kuhr, WG AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - Our prior designs for molecular-based information storage devices have employed multiple redox-active units organized in weakly coupled, covalently linked arrays. To explore a simpler design, we report here the synthesis of porphyrin arrays where porphyrins with identical oxidation potentials are directly linked to one another instead of joined via a molecular linker. Oxidative coupling with AgPF(6) of zinc(II)-5,15-bis(4-tert-butylphenyl)-10-phenylporphyrin, obtained by a rational synthesis, afforded the expected dimer joined by a meso-meso linkage and an unexpected trimer joined by meso-meso linkages. For attachment to an electroactive surface we synthesized a meso-linked porphyrin dimer with a thiol-linker in one of the meso positions. The S-acetyl protecting group was used to avoid handling free thiol groups. Coupling of zinc(II)-5,10,15-tris(3, 5-di-tert-butylphenyl)porphyrin ("upper half") and zinc(II)-5-[4-(S-acetylthio)phenyl]-10,20-bis(3, 5-di-tert-butylphenyl)porphyrin ("lower half") afforded three different meso-linked dimers with the desired dimer as the main product. Electrochemical examination of the meso-linked dimer in solution shows that the first two oxidation potentials of the array differ by approximately 0.15 V and straddle the value exhibited by the monomeric constituents. The third and fourth oxidation potentials of the array are also split although to a lesser extent ( approximately 0.08 V) than the first and second. For the meso-linked trimer, the first three oxidation waves are also split; however, these waves are severely overlapped. The electrochemical behavior of the dimers and trimer is indicative of strong electronic interactions among the porphyrins. The thiol-derivatized meso-linked dimers form self-assembled monolayers (SAMs) on gold via in situ cleavage of the S-acetylthio protecting group. The porphyrin SAM exhibits four well-resolved oxidation waves. Regardless, the meso-meso linkage is relatively unstable upon formation of the pi-cation radical(s). This characteristic indicates that the structural motif is of limited utility for molecular information storage elements. DA - 2000/11/3/ PY - 2000/11/3/ DO - 10.1021/jo000489e VL - 65 IS - 22 SP - 7371-7378 SN - 1520-6904 ER - TY - JOUR TI - Epistatic repression of PHANTASTICA and class 1 KNOTTED genes is uncoupled in tomato AU - Koltai, H AU - Bird, DM T2 - PLANT JOURNAL AB - Summary Class 1 KNOTTED genes ( KNOX ) and PHANTASTICA ( PHAN ) are both central to meristem establishment and maintenance and, in maize and Antirrhinum , it has been proposed that PHAN acts as an epigenetic repressor of KNOX . In tomato, a distinct spatial distribution of Tkn2 KNOX transcripts compared to Antirrhinum and maize suggests either a different spatial distribution of tomato PHAN ( Le‐phan ) transcripts, or that PHAN alone is insufficient for KNOX repression in tomato. We established the pattern of Le‐phan expression, including a first demonstration of PHAN expression in healthy roots, and found Le‐phan and Tkn2 transcripts to be temporally and spatially coincidental, with PHAN exhibiting an expression pattern in tomato distinct from that in plants with simple leaves. Our results imply that the expression of Le‐phan is insufficient for the repression of Tkn2 in tomato and suggest an expanded role for either gene in the establishment of cell identity in plant development. DA - 2000/6// PY - 2000/6// DO - 10.1046/j.1365-313X.2000.00754.x VL - 22 IS - 5 SP - 455-459 SN - 0960-7412 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0034086796&partnerID=MN8TOARS ER - TY - JOUR TI - Differential expression of genes encoding cell wall proteins in vascular tissues from vertical and bent loblolly pine trees AU - Zhang, Y. AU - Sederoff, R. R. AU - Allona, I. T2 - Tree Physiology DA - 2000/// PY - 2000/// VL - 20 IS - 7 SP - 457-466 ER - TY - JOUR TI - Commercial fungicide formulations induce in vitro oospore formation and phenotypic change in mating type in Phytophthora infestans AU - Groves, CT AU - Ristaino, JB T2 - PHYTOPATHOLOGY AB - A wide range of commercially formulated fungicides cause in vitro effects on mating behavior in specific isolates of Phytophthora infestans, the causal agent of late blight of potato and tomato. Four isolates of P. infestans representing each of the four common US genotypes, US-1, US-6, US-7, and US-8 and varying in their sensitivity to metalaxyl, were exposed to a variety of fungicides used to control late blight in petri dish assays at concentrations ranging from 1 to 100 μg a.i./ml. Exposure of each of these normally heterothallic single mating type isolates of P. infestans to 9 of the 11 commercial fungicide formulations tested resulted in the formation of oospores after 2 to 4 weeks. The highest numbers of oospores were formed on media amended with Ridomil 2E (metalaxyl) and Ridomil Gold EC (mefenoxam) at 0.1 to 10 μg a.i./ml, averaging as many as 471 and 450 oospores per petri dish, respectively. Several other fungicides including Maneb, Manzate (Mancozeb), Curzate (cymoxanil + mancozeb), and Acrobat MZ (dimethomorph + mancozeb) also induced oospore formation, producing from 0 to 200 oospores per plate at fungicide concentrations from 0.1 to 10 μg a.i./ml. The metalaxyl resistant isolates formed oospores in response to the fungicides more often than the metalaxyl sensitive isolates. No oospores were formed on media amended with Bravo (chlorothalonil) or Tattoo C (chlorothalonil + propamocarb HCl) and these compounds completely suppressed growth of the isolates at 0.1 and 1 μg a.i./ml. Three metalaxyl resistant A2 isolates mated with both A1 and A2 isolates after exposure to the fungicides Ridomil 2E and Ridomil Gold EC. Alterations in mating type expression were also observed in a metalaxyl sensitive A1 isolate after exposure to Benlate (benomyl). Copious amounts of chemicals are applied annually to potato and tomato production areas to control late blight. Our results indicate that a wide range of chemically diverse fungicides can induce normally heterothallic metalaxyl resistant isolates of P. infestans to form oospores in vitro after short exposures to the fungicides. DA - 2000/11// PY - 2000/11// DO - 10.1094/PHYTO.2000.90.11.1201 VL - 90 IS - 11 SP - 1201-1208 SN - 0031-949X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0033745281&partnerID=MN8TOARS KW - fungicide resistance KW - Irish potato famine KW - oomycetes KW - potato late blight KW - Solanum tuberosum ER - TY - JOUR TI - Vitamin B-6 (pyridoxine) and its derivatives are efficient singlet oxygen quenchers and potential fungal antioxidants AU - Bilski, P AU - Li, MY AU - Ehrenshaft, M AU - Daub, ME AU - Chignell, CF T2 - PHOTOCHEMISTRY AND PHOTOBIOLOGY AB - Vitamin B6 (pyridoxine, 1) and its derivatives: pyridoxal (2), pyridoxal 5-phosphate (3) and pyridoxamine (4) are important natural compounds involved in numerous biological functions. Pyridoxine appears to play a role in the resistance of the filamentous fungus Cercospora nicotianae to its own abundantly produced strong photosensitizer of singlet molecular oxygen (1O2), cercosporin. We measured the rate constants (kq) for the quenching of 1O2 phosphorescence by 1-4 in D2O. The respective total (physical and chemical quenching) kq values are: 5.5 x 10(7) M-1 s-1 for 1; 7.5 x 10(7) M-1 s-1 for 2, 6.2 x 10(7) M-1 s-1 for 3 and 7.5 x 10(7) M-1 s-1 for 4, all measured at pD 6.2. The quenching efficacy increased up to five times in alkaline solutions and decreased approximately 10 times in ethanol. Significant contribution to total quenching by chemical reaction(s) is suggested by the degradation of all the vitamin derivatives by 1O2, which was observed as declining absorption of the pyridoxine moiety upon aerobic irradiation of RB used to photosensitize 1O2. This photodegradation was completely stopped by azide, a known physical quencher of 1O2. The pyridoxine moiety can also function as a redox quencher for excited cercosporin by forming the cercosporin radical anion, as observed by electron paramagnetic resonance. All B6 vitamers fluoresce upon UV excitation. Compounds 1 and 4 emit fluorescence at 400 nm, compound 2 at 450 nm and compound 3 at 550 nm. The fluorescence intensity of 3 increased approximately 10 times in organic solvents such as ethanol and 1,2-propanediol compared to aqueous solutions, suggesting that fluorescence may be used to image the distribution of 1-4 in Cercospora to understand better the interactions of pyridoxine and 1O2 in the living fungus. DA - 2000/2// PY - 2000/2// DO - 10.1562/0031-8655(2000)071<0129:SIPVBP>2.0.CO;2 VL - 71 IS - 2 SP - 129-134 SN - 1751-1097 ER - TY - JOUR TI - Variation and selection at the CAULIFLOWER floral homeotic gene accompanying the evolution of domesticated Brassica oleracea AU - Purugganan, M. D. AU - Boyles, A. L. AU - Suddith, J. I. T2 - Genetics DA - 2000/// PY - 2000/// VL - 155 IS - 2 SP - 855-862 ER - TY - JOUR TI - Use of matrix attachment regions (MARs) to minimize transgene silencing AU - Allen, GC AU - Spiker, S AU - Thompson, WF T2 - PLANT MOLECULAR BIOLOGY DA - 2000/6// PY - 2000/6// DO - 10.1023/A:1006424621037 VL - 43 IS - 2-3 SP - 361-376 SN - 0167-4412 KW - chromatin structure KW - gene silencing KW - MAR KW - nuclear matrix KW - nuclear scaffold KW - SAR ER - TY - JOUR TI - The nucleotide-replacement spectrum under somatic hypermutation exhibits microsequence dependence that is strand-symmetric and distinct from that under germline mutation AU - Cowell, LG AU - Kepler, TB T2 - JOURNAL OF IMMUNOLOGY AB - Abstract Somatic mutation is a fundamental component of acquired immunity. Although its molecular basis remains undetermined, the sequence specificity with which mutations are introduced has provided clues to the mechanism. We have analyzed data representing over 1700 unselected mutations in V gene introns and nonproductively rearranged V genes to identify the sequence specificity of the mutation spectrum—the distribution of resultant nucleotides. In other words, we sought to determine what effects the neighboring bases have on what a given base mutates “to.” We find that both neighboring bases have a significant effect on the mutation spectrum. Their influences are complicated, but much of the effect can be characterized as enhancing homogeneity of the mutated DNA sequence. In contrast to what has been reported for the sequence specificity of the “targeting” mechanism, that of the spectrum is notably symmetric under complementation, indicating little if any strand bias. We compared the spectrum to that found previously for germline mutations as revealed by analyzing pseudogene sequences. We find that the influences of nearest neighbors are quite different in the two datasets. Altogether, our findings suggest that the mechanism of somatic hypermutation is complex, involving two or more stages: introduction of mis-pairs and their subsequent resolution, each with distinct sequence specificity and strand bias. DA - 2000/2/15/ PY - 2000/2/15/ DO - 10.4049/jimmunol.164.4.1971 VL - 164 IS - 4 SP - 1971-1976 SN - 1550-6606 ER - TY - JOUR TI - Spontaneous mutation in the db gene results in obesity and diabetes in CD-1 outbred mice AU - Brown, J. A. AU - Chua, S. C. AU - Liu, S. M. AU - Andrews, M. T. AU - Vandenbergh, J. G. T2 - American Journal of Physiology DA - 2000/// PY - 2000/// VL - 278 IS - 2 pt.2 SP - R320-330 ER - TY - JOUR TI - Reproductive strategies and karyotype of the burrowing nematode, Radopholus similis AU - Kaplan, D. T. AU - Opperman, C. H. T2 - Journal of Nematology DA - 2000/// PY - 2000/// VL - 32 IS - 2 SP - 126-133 ER - TY - JOUR TI - Quantitative evaluation of alternative mechanisms of blood disposition of di(n-butyl) phthalate and mono(n-butyl) phthalate in rats AU - Keys, DA AU - Wallace, DG AU - Kepler, TB AU - Conolly, RB T2 - TOXICOLOGICAL SCIENCES AB - Phthalate esters are ubiquitous, low-level environmental contaminants that induce testicular toxicity in laboratory animals. The diester is rapidly metabolized in the gut to the monoester, which causes the testicular toxicity. Several physiologically based pharmacokinetic (PBPK) model structures have been evaluated for di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate (MEHP). The objective of this study was to test these PBPK models for a less lipophilic phthalate diester, di(n-butyl) phthalate (DBP), and monoester, mono(n-butyl) phthalate (MBP). Alternate models describing enterohepatic circulation, diffusion-limitation, tissue pH gradients (pH trapping), and a simpler, flow-limited model were evaluated. A combined diffusion-limited and pH trapping model was also tested. MBP tissue:blood partition coefficients were similar when determined either experimentally by a nonvolatile, vial equilibration technique or algorithmically. All other parameters were obtained from the literature or estimated from MBP blood concentrations following intravenous or oral exposure to DBP or MBP. A flow-limited model was unable to predict MBP blood levels, whereas each alternative model had statistically better predictions. The combined diffusion-limited and pH trapping model was the best overall, having the highest log-likelihood function value. This result is consistent with a previous finding that the pH trapping model was the best model for describing DEHP and MEHP blood dosimetry, though it was necessary to extend the model to include diffusion-limitation. The application of the pH trapping model is a step toward developing a generic model structure for all phthalate esters, though more work is required before a generic structure can be identified with confidence. Development of a PBPK model structure applicable to all phthalate esters would support more realistic assessments of risk to human health from exposure to one or more members of this class of compounds. DA - 2000/2// PY - 2000/2// DO - 10.1093/toxsci/53.2.173 VL - 53 IS - 2 SP - 173-184 SN - 1096-0929 KW - phthalates KW - DBP KW - MBP KW - PBPK KW - model KW - flow-limited KW - diffusion-limited KW - pH trapping KW - enterohepatic circulation KW - log-likelihood ratio test ER - TY - JOUR TI - Plant development: A role for sterols in embryogenesis AU - Clouse, S. D. T2 - Current Biology AB - The Arabidopsis mutants fackel and sterol methyltransferase 1 have defects associated with body organization of the seedling. Molecular analysis of these mutants has revealed that plant sterols may be key signaling molecules influencing position-dependent cell fate during embryonic development. DA - 2000/// PY - 2000/// DO - 10.1016/S0960-9822(00)00639-4 VL - 10 IS - 16 SP - R601-604 ER - TY - JOUR TI - Phylogenetic analysis of geographically diverse Radopholus similis via rDNA sequence reveals a monomorphic motif AU - Kaplan, D. T. AU - Thomas, W. K. AU - Frisse, L. M. AU - Sarah, J. L. AU - Stanton, J. M. AU - Speijer, P. R. AU - Marin, D. H. AU - Opperman, C. H. T2 - Journal of Nematology DA - 2000/// PY - 2000/// VL - 32 IS - 2 SP - 134-142 ER - TY - JOUR TI - Peliosis hepatis in a dog infected withBartonella henselae AU - Kitchell, Barbara E. AU - Fan, Timothy M. AU - Kordick, Dorsey AU - Breitschwerdt, Edward B. AU - Wollenberg, Gordon AU - Lichtensteiger, Carol A. T2 - Journal of the American Veterinary Medical Association AB - A 6-year-old spayed female Golden Retriever was examined because of generalized weakness and abdominal distention. Abdominal ultrasonography revealed a large quantity of peritoneal fluid. In addition, the liver appeared larger than normal and contained multiple, small, nodular masses and cyst-like structures. Abdominal exploratory surgery was performed, and 5 L of serosanguineous peritoneal fluid was removed. Gross lesions were not found in the stomach, kidneys, intestines, adrenal glands, or urinary bladder. There were diffuse cystic nodules in all liver lobes. The dog did not recover from anesthesia. A diagnosis of peliosis hepatis was made on the basis of gross and histologic appearance of the liver. A polymerase chain reaction assay revealed Bartonella henselae DNA in liver specimens. To our knowledge, this is the first report of molecular evidence of B henselae infection in a dog with peliosis hepatis. DA - 2000/2// PY - 2000/2// DO - 10.2460/javma.2000.216.519 VL - 216 IS - 4 SP - 519-523 J2 - Journal of the American Veterinary Medical Association LA - en OP - SN - 0003-1488 UR - http://dx.doi.org/10.2460/javma.2000.216.519 DB - Crossref ER - TY - PAT TI - Method for reducing expression variability of transgenes in plant cells AU - Thompson, W. AU - Allen, G. AU - Mankin, S. C2 - 2000/// DA - 2000/// PY - 2000/// ER - TY - JOUR TI - Inferring linkage disequilibrium between a polymorphic marker locus and a trait locus in natural populations AU - Luo, Z. W. AU - Tao, S. H. AU - Zeng, Z. B. T2 - Genetics DA - 2000/// PY - 2000/// VL - 156 IS - 1 SP - 457-467 ER - TY - JOUR TI - Geminiviruses - Models for plant DNA replication, transcription and cell cycle regulation ([correction to] vol 35, pg 105, 2000) AU - Hanley-Bowdoin, L. AU - Settlage, S. B. AU - Orozco, B. M. AU - Nagar, S. AU - Robertson, D. T2 - Critical Reviews in Biochemistry and Molecular Biology DA - 2000/// PY - 2000/// VL - 35 IS - 4 SP - U4 ER - TY - JOUR TI - Dihydrocercosporin singlet oxygen production and subcellular localization: A possible defense against cercosporin phototoxicity in Cercospora AU - Daub, ME AU - Li, M AU - Bilski, P AU - Chignell, CF T2 - PHOTOCHEMISTRY AND PHOTOBIOLOGY AB - Fungi in the genus Cercospora produce cercosporin, a potent singlet oxygen (1O2)-generating photosensitizer that plays a critical role in the ability of these fungi to parasitize plants. Although plants, mice, bacteria and many fungi are sensitive to cercosporin, Cercospora species are resistant to its toxicity. The cellular resistance of these fungi to cercosporin has been correlated with fungal cell surface reducing ability and the ability to maintain cercosporin in a chemically reduced state. As a model for reduced cercosporin we employed a reduced, acetylated derivative (hexaacetyl-dihydrocercosporin, HAC) that we tested for 1O2 production in a range of solvents. We found that as a 1O2 photosensitizer, HAC was only moderately effective in organic solvents (phi SO = 0.14-0.18) and very poor in water (phi SO = 0.02-0.04). By contrast, the 1O2 quantum yield of cercosporin itself was unaffected by solvent (phi SO = 0.84-0.97). To investigate the localization of reduced cercosporin in fungal cells, we developed a fluorescence assay using laser scanning confocal microscopy. This assay showed a uniform green fluorescence, indicative of reduced cercosporin, in the cytoplasm of hyphal cells treated with cercosporin. We hypothesize that the main protection mechanism against cercosporin phototoxicity in the fungus consists of transformation of cercosporin to a reduced state and localization of this reduced form in the aqueous compartment of the cell, thus decreasing intracellular 1O2 production to levels that can be tolerated by the fungus. In addition, we have, for the first time, directly detected 1O2 phosphorescence from fungal culture, either stained with the photosensitizer rose bengal or actively synthesizing cercosporin, demonstrating 1O2 production in vivo and from cercosporin in culture. DA - 2000/2// PY - 2000/2// DO - 10.1562/0031-8655(2000)071<0135:SIPDSO>2.0.CO;2 VL - 71 IS - 2 SP - 135-140 SN - 0031-8655 ER - TY - JOUR TI - Cyclic CD8+lymphopenia in dogs experimentally infected with Bartonella vinsonii subsp berkhoffii AU - Pappalardo, BL AU - Brown, T AU - Gebhardt, D AU - Sontakke, S AU - Breitschwerdt, EB T2 - VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY AB - Until recently, it was presumed that Bartonella vinsonii only infected voles, a species of North American rodents. In April of 1993, however, our laboratory isolated a novel subspecies of B. vinsonii (B. vinsonii subsp. berkhoffii) from the blood of a dog diagnosed with vegetative valvular endocarditis. Subsequently, based on a seroepidemiologic survey of dogs from North Carolina and Virginia presenting for a variety of medical problems, we found evidence supporting a potentially important association between B. vinsonii and Ehrlichia canis co-infection in dogs. In the following study, eight dogs were infected with B. vinsonii: four specific pathogen free dogs and four dogs that had previously been infected with E. canis. Flow cytometric analysis of peripheral blood lymphocytes revealed a cyclic elevation of the CD4/CD8 T-cell ratio that correlated with cyclic CD8+ lymphopenia in all dogs infected with B. vinsonii, regardless of prior exposure to E. canis. DA - 2000/6/30/ PY - 2000/6/30/ DO - 10.1016/S0165-2427(00)00182-3 VL - 75 IS - 1-2 SP - 43-57 SN - 0165-2427 KW - mAb, monoclonal antibody KW - FBS, fetal bovine serum KW - PID, post-inoculation day KW - PBL, peripheral blood lymphocytes KW - LN, lymph node ER - TY - JOUR TI - Characterization and differential expression of a human gene family of olfactomedin-related proteins AU - Kulkarni, NH AU - Karavanich, CA AU - Atchley, WR AU - Anholt, RRH T2 - GENETICAL RESEARCH AB - Olfactomedin-related proteins are secreted glycoproteins with conserved C-terminal motifs. Olfactomedin was originally identified as the major component of the mucus layer that surrounds the chemosensory dendrites of olfactory neurons. Homologues were subsequently found also in other tissues, including the brain and in species ranging from Caenorhabditis elegans to Homo sapiens. Most importantly, the TIGR/myocilin protein, expressed in the eye and associated with the pathogenesis of glaucoma, is an olfactomedin-related protein. The prevalence of olfactomedin-related proteins among species and their identification in different tissues prompted us to investigate whether a gene family exists within a species, specifically Homo sapiens. A GenBank search indeed revealed an entire human gene family of olfactomedin-related proteins with at least five members, designated hOlfA through hOlfD and the TIGR/myocilin protein. hOlfA corresponds to the rat neuronal AMZ protein. Phylogenetic analyses of 18 olfactomedin-related sequences resolved four distinct subfamilies. Among the human proteins, hOlfA and hOlfC, both expressed in brain, are most closely related. Northern blot analyses of 16 human tissues demonstrated highly specific expression patterns: hOlfA is expressed in brain, hOlfB in pancreas and prostate, hOlfC in cerebellum, hOlfD in colon, small intestine and prostate and TIGR/myocilin in heart and skeletal muscle. The link between TIGR/myocilin and ocular hypertension and the expression of several of these proteins in mucus-lined tissues suggest that they play an important role in regulating physical properties of the extracellular environment. Future studies can now assess whether other members of this gene family, like TIGR/myocilin, are also associated with human disease processes. DA - 2000/8// PY - 2000/8// DO - 10.1017/S0016672300004584 VL - 76 IS - 1 SP - 41-50 SN - 0016-6723 ER - TY - JOUR TI - Antisense and sense expression of a sucrose binding protein homologue gene from soybean in transgenic tobacco affects plant growth and carbohydrate partitioning in leaves AU - Pedra, JHF AU - Delu, N AU - Pirovani, CP AU - Contim, LAS AU - Dewey, RE AU - Otoni, WC AU - Fontes, EPB T2 - PLANT SCIENCE AB - We isolated a cDNA from a soybean library, which encodes sucrose binding protein (SBP) homologue, designated S-64. To analyze the function of the SBP homologue, transgenic tobacco plants were obtained by introducing chimeric genes containing the s-64 coding region linked to the 35S CaMV promoter, either in the sense or antisense orientation, via Agrobacterium tumefaciens-mediated transformation. The accumulation of the SBP homologue was increased in transgenic plants expressing the heterologous sbp gene, whereas those expressing the antisense construct had reduced levels of the protein. The antisense transgenic plants developed symptoms characteristic of an inhibition of sucrose translocation and displayed a reduction in plant growth and development. In contrast, overexpression of the protein accelerated plant growth and the onset of flowering induction. The overall developmental performance of the transgenic plants was correlated with their photosynthetic rate under normal conditions. While photosynthesis in the antisense lines was decreased, in the sense lines photosynthetic rates were increased. Furthermore, both antisense repression and overexpression of the SBP homologue in transgenic lines altered carbohydrate partitioning in mature leaves. Taken together, these results indicate that S-64 protein is functionally analogous to SBP, representing an important component of the sucrose translocation pathway in plants. DA - 2000/3/7/ PY - 2000/3/7/ DO - 10.1016/S0168-9452(99)00223-X VL - 152 IS - 1 SP - 87-98 SN - 1873-2259 KW - Nicotiana KW - soybean KW - sucrose binding protein KW - sucrose transport ER - TY - JOUR TI - 17 beta-Estradiol and ICI-182780 regulate the hair follicle cycle in mice through an estrogen receptor-alpha pathway AU - Chanda, S AU - Robinette, CL AU - Couse, JF AU - Smart, RC T2 - AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM AB - Estradiol (E(2)) applied topically twice weekly to mouse skin at doses as low as 1 nmol inhibited hair growth by blocking the transition of the hair follicle from the resting phase (telogen) to the growth phase (anagen). In contrast, application of 98% for H2PH2Pc). (3) Charge transfer involving the excited phthalocyanine and the porphyrin occurs to a limited degree (typically <10%) depending on the redox characteristics of the chromophores. (4) The desirable strong emission properties of monomeric phthalocyanines are retained in most of the dyads (Φf = 0.37–0.75). This paper establishes the foundation for utilizing phthalocyanines as strong-red absorbers, energy-transfer acceptors, and bright emitters in conjunction with porphyrin-based molecular photonic devices. DA - 2000/// PY - 2000/// DO - 10.1039/a906273d VL - 10 IS - 2 SP - 283–296 ER - TY - JOUR TI - Stringent control of transgene expression in Arabidopsis thaliana using the Top10 promoter system AU - Love, J AU - Scott, AC AU - Thompson, WF T2 - PLANT JOURNAL AB - Summary We show that the tightly regulated tetracycline‐sensitive Top10 promoter system (Weinmann et al . Plant J. 1994, 5, 559–569) is functional in Arabidopsis thaliana . A pure breeding A. thaliana line (JL‐tTA/8) was generated which expressed a chimeric fusion of the tetracycline repressor and the activation domain of Herpes simplex virus (tTA), from a single transgenic locus. Plants from this line were crossed with transgenics carrying the ER‐targeted green fluorescent protein coding sequence ( mGFP 5 ) under control of the Top10 promoter sequence. Progeny from this cross displayed ER‐targeted GFP fluorescence throughout the plant, indicating that the tTA–Top10 promoter interaction was functional in A. thaliana . GFP expression was repressed by 100 ng ml −1 tetracycline, an order of magnitude lower than the concentration used previously to repress expression in Nicotiana tabacum . Moreover, the level of GFP expression was controlled by varying the concentration of tetracycline in the medium, allowing a titred regulation of transgenic activity that was previously unavailable in A. thaliana . The kinetics of GFP activity were determined following de‐repression of the Top10::mGFP 5 transgene, with a visible ER‐targeted GFP signal appearing from 24 to 48 h after de‐repression. DA - 2000/3// PY - 2000/3// DO - 10.1046/j.1365-313x.2000.00706.x VL - 21 IS - 6 SP - 579-588 SN - 0960-7412 ER - TY - JOUR TI - Rapid identification and differentiation of Bartonella species using a single-step PCR assay AU - Jensen, W. A. AU - Fall, M. Z. AU - Rooney, J. AU - Kordick, D. L. AU - Breitschwerdt, E. B. T2 - Journal of Clinical Microbiology DA - 2000/// PY - 2000/// VL - 38 IS - 5 SP - 1717-1722 ER - TY - JOUR TI - Premature termination codons destabilize ferredoxin-1 mRNA when ferredoxin-1 is translated AU - Petracek, ME AU - Nuygen, T AU - Thompson, WF AU - Dickey, LF T2 - PLANT JOURNAL AB - Summary Ferredoxin‐1 ( Fed‐1 ) mRNA is poorly translated in dark‐treated tobacco ( Nicotiana tabacum ) leaves, resulting in destabilization of Fed‐1 mRNA and a differential light/dark accumulation of the mRNA. Insertion of nonsense codons within the Fed‐1 coding sequence disrupts the light regulation of Fed‐1 mRNA abundance. Here we show that the nonsense codon effect results primarily from lowering the Fed‐1 mRNA stability in light‐treated leaf tissue and in rapidly growing tobacco cell cultures, but not in dark‐treated leaf tissue. These results suggest that nonsense codons trigger a decay pathway distinct from that seen for Fed‐1 mRNA in the dark. We propose that nonsense‐mediated decay of nonsense‐containing Fed‐1 mRNA occurs in light‐treated leaves and in non‐photosynthetic tobacco culture cells where Fed‐1 mRNA is being actively translated. DA - 2000/3// PY - 2000/3// DO - 10.1046/j.1365-313x.2000.00705.x VL - 21 IS - 6 SP - 563-569 SN - 1365-313X ER - TY - JOUR TI - Genotype-environment interaction for quantitative trait loci affecting life span in Drosophila melanogaster AU - Vieira, C. AU - Pasyukova, E. G. AU - Zeng, Z. B. AU - Hackett, J. B. AU - Lyman, R. F. AU - Mackay, T. F. C. T2 - Genetics DA - 2000/// PY - 2000/// VL - 154 IS - 1 SP - 213-227 ER - TY - JOUR TI - Genetic architecture of a morphological shape difference between two Drosophila species AU - Zeng, Z. B. AU - Liu, J. J. AU - Stam, L. F. AU - Kao, C. H. AU - Mercer, J. M. AU - Laurie, C. C. T2 - Genetics DA - 2000/// PY - 2000/// VL - 154 IS - 1 SP - 299-310 ER - TY - JOUR TI - Familial glomerulonephropathy in a litter of Beagles AU - Rha, Ji-Yeun AU - Labato, Mary Anna AU - Ross, Linda A. AU - Breitschwerdt, Edward AU - Alroy, Joseph T2 - Journal of the American Veterinary Medical Association AB - Membranoproliferative glomerulonephropathy was diagnosed in 5 of 7 adult Beagles from the same litter. Dogs were raised in more than 1 area of the United States. One died without evidence of renal disease when it was 3 years old. At 8 years of age, 2 dogs developed signs of uremia, including polyuria, polydipsia, and infrequent episodes of anorexia and vomiting. Serum biochemical variables and urine specific gravity values were consistent with renal azotemia. Both dogs had proteinuria. Although healthy, 3 of the 4 remaining Beagles had proteinuria. Of these 3, only 1 was azotemic. Membranoproliferative glomerulonephritis was diagnosed on the basis of results of histologic examination of renal biopsy specimens from 4 of the dogs. Electron microscopy performed on 3 of the renal biopsy specimens revealed identical lesions, consisting of an extremely thickened glomerular basement membrane with multilaminar splitting. Immunoglobulin or amyloid deposits were not detected. On the basis of similar clinicopathologic abnormalities, common genetic background, and identical histopathologic and electron microscopic findings, familial renal disease was diagnosed. Additional studies involving other related Beagles are needed to identify the hereditary nature of membranoproliferative glomerulonephropathy in Beagles. DA - 2000/1// PY - 2000/1// DO - 10.2460/javma.2000.216.46 VL - 216 IS - 1 SP - 46-50 J2 - Journal of the American Veterinary Medical Association LA - en OP - SN - 0003-1488 UR - http://dx.doi.org/10.2460/javma.2000.216.46 DB - Crossref ER - TY - JOUR TI - A single deletion in the membrane-proximal region of the Sindbis virus glycoprotein E2 endodomain blocks virus assembly AU - Hernandez, R AU - Lee, H AU - Nelson, C AU - Brown, DT T2 - JOURNAL OF VIROLOGY AB - The envelopment of the Sindbis virus nucleocapsid in the modified cell plasma membrane involves a highly specific interaction between the capsid (C) protein and the endodomain of the E2 glycoprotein. We have previously identified a domain of the Sindbis virus C protein involved in binding to the E2 endodomain (H. Lee and D. T. Brown, Virology 202:390-400, 1994). The C-E2 binding domain resides in a hydrophobic cleft with C Y180 and W247 on opposing sides of the cleft. Structural modeling studies indicate that the E2 domain, which is proposed to bind the C protein (E2 398T, 399P, and 400Y), is located at a sufficient distance from the membrane to occupy the C protein binding cleft (S. Lee, K. E. Owen, H. K. Choi, H. Lee, G. Lu, G. Wengler, D. T. Brown, M. G. Rossmann, and R. J. Kuhn, Structure 4:531-541, 1996). To measure the critical spanning length of the E2 endodomain which positions the TPY domain into the putative C binding cleft, we have constructed a deletion mutant, DeltaK391, in which a nonconserved lysine (E2 K391) at the membrane-cytoplasm junction of the E2 tail has been deleted. This mutant was found to produce very low levels of virus from BHK-21 cells due to a defect in an unidentified step in nucleocapsid binding to the E2 endodomain. In contrast, DeltaK391 produced wild-type levels of virus from tissue-cultured mosquito cells. We propose that the phenotypic differences displayed by this mutant in the two diverse host cells arise from fundamental differences in the lipid composition of the insect cell membranes which affect the physical and structural properties of membranes and thereby virus assembly. The data suggest that these viruses have evolved properties adapted specifically for assembly in the diverse hosts in which they grow. DA - 2000/5// PY - 2000/5// DO - 10.1128/JVI.74.9.4220-4228.2000 VL - 74 IS - 9 SP - 4220-4228 SN - 1098-5514 ER - TY - JOUR TI - Voronoi diagrams and convex hulls of random moving points AU - Dwyer, R. A. T2 - Discrete and Computational Geometry DA - 2000/// PY - 2000/// VL - 23 IS - 3 SP - 343-365 ER - TY - JOUR TI - Genetic mapping of the Tsw locus for resistance to the Tospovirus Tomato spotted wilt virus in Capsicum spp. and its relationship to the Sw-5 gene for resistance to the same pathogen in tomato AU - Jahn, M AU - Paran, I AU - Hoffmann, K AU - Radwanski, ER AU - Livingstone, KD AU - Grube, RC AU - Aftergoot, E AU - Lapidot, M AU - Moyer, J T2 - MOLECULAR PLANT-MICROBE INTERACTIONS AB - The Tsw gene conferring dominant resistance to the Tospovirus Tomato spotted wilt virus (TSWV) in Capsicum spp. has been tagged with a random amplified polymorphic DNA marker and mapped to the distal portion of chromosome 10. No mapped homologues of Sw-5, a phenotypically similar dominant TSWV resistance gene in tomato, map to this region in C. annuum, although a number of Sw-5 homologues are found at corresponding positions in pepper and tomato. The relationship between Tsw and Sw-5 was also examined through genetic studies of TSWV. The capacity of TSWV-A to overcome the Tsw gene in pepper and the Sw-5 gene in tomato maps to different TSWV genome segments. Therefore, despite phenotypic and genetic similarities of resistance in tomato and pepper, we infer that distinct viral gene products control the outcome of infection in plants carrying Sw-5 and Tsw, and that these loci do not appear to share a recent common evolutionary ancestor. DA - 2000/6// PY - 2000/6// DO - 10.1094/MPMI.2000.13.6.673 VL - 13 IS - 6 SP - 673-682 SN - 0894-0282 KW - comparative genetic mapping KW - Nx KW - Solanaceae KW - viral genome reassortment ER - TY - JOUR TI - A rapid chromatographic method to separate the subunits of bacterial luciferase in urea-containing buffer AU - Clark, A. C. AU - Noland, B. W. AU - Baldwin, T. O. T2 - Bioluminescence and chemiluminescence, pt. C CN - QP601 .M49 v.305 DA - 2000/// PY - 2000/// VL - 305 SP - 157-164 ER - TY - JOUR TI - The multifunctional character of a geminivirus replication protein is reflected by its complex oligomerization properties AU - Orozco, BM AU - Kong, LJ AU - Batts, LA AU - Elledge, S AU - Hanley-Bowdoin, L T2 - JOURNAL OF BIOLOGICAL CHEMISTRY AB - Tomato golden mosaic virus (TGMV), a member of the geminivirus family, encodes one essential replication protein, AL1, and recruits the rest of the DNA replication apparatus from its plant host. TGMV AL1 is an oligomeric protein that binds double-stranded DNA and catalyzes cleavage and ligation of single-stranded DNA. The oligomerization domain, which is required for DNA binding, maps to a region that displays strong sequence and structural homology to other geminivirus Rep proteins. To assess the importance of conserved residues, we generated a series of site-directed mutations and analyzed their impact on AL1 function in vitro and in vivo. Two-hybrid experiments revealed that mutation of amino acids 157–159 inhibited AL1-AL1 interactions, whereas mutations at nearby residues reduced complex stability. Changes at positions 157–159 also disrupted interaction between the full-length mutant protein and a glutathione S-transferase-AL1 oligomerization domain fusion in insect cells. The mutations had no detectable effect on oligomerization when both proteins contained full-length AL1 sequences, indicating that AL1 complexes can be stabilized by amino acids outside of the oligomerization domain. Nearly all of the oligomerization domain mutants were inhibited or severely attenuated in their ability to support AL1-directed viral DNA replication. In contrast, the same mutants were enhanced for AL1-mediated transcriptional repression. The replication-defective AL1 mutants also interfered with replication of a TGMV A DNA encoding wild type AL1. Full-length mutant AL1 was more effective in the interference assays than truncated proteins containing the oligomerization domain. Together, these results suggested that different AL1 complexes mediate viral replication and transcriptional regulation and that replication interference involves multiple domains of the AL1 protein. Tomato golden mosaic virus (TGMV), a member of the geminivirus family, encodes one essential replication protein, AL1, and recruits the rest of the DNA replication apparatus from its plant host. TGMV AL1 is an oligomeric protein that binds double-stranded DNA and catalyzes cleavage and ligation of single-stranded DNA. The oligomerization domain, which is required for DNA binding, maps to a region that displays strong sequence and structural homology to other geminivirus Rep proteins. To assess the importance of conserved residues, we generated a series of site-directed mutations and analyzed their impact on AL1 function in vitro and in vivo. Two-hybrid experiments revealed that mutation of amino acids 157–159 inhibited AL1-AL1 interactions, whereas mutations at nearby residues reduced complex stability. Changes at positions 157–159 also disrupted interaction between the full-length mutant protein and a glutathione S-transferase-AL1 oligomerization domain fusion in insect cells. The mutations had no detectable effect on oligomerization when both proteins contained full-length AL1 sequences, indicating that AL1 complexes can be stabilized by amino acids outside of the oligomerization domain. Nearly all of the oligomerization domain mutants were inhibited or severely attenuated in their ability to support AL1-directed viral DNA replication. In contrast, the same mutants were enhanced for AL1-mediated transcriptional repression. The replication-defective AL1 mutants also interfered with replication of a TGMV A DNA encoding wild type AL1. Full-length mutant AL1 was more effective in the interference assays than truncated proteins containing the oligomerization domain. Together, these results suggested that different AL1 complexes mediate viral replication and transcriptional regulation and that replication interference involves multiple domains of the AL1 protein. tomato golden mosaic virus activation domain glutathioneS-transferase maize streak virus Geminiviruses are a large family of plant viruses with circular, single-stranded DNA genomes that replicate in the nuclei of infected cells (reviewed in Ref. 1.Hanley-Bowdoin L. Settlage S.B. Orozco B.M. Nagar S. Robertson D. CRC Crit. Rev. Plant Sci. 1999; 18: 71-106Crossref Google Scholar). The single-stranded genome is converted to a double-stranded DNA that serves as the template for rolling circle replication (2.Saunders K. Lucy A. Stanley J. Nucleic Acids Res. 1991; 19: 2325-2330Crossref PubMed Scopus (167) Google Scholar, 3.Stenger D.C. Revington G.N. Stevenson M.C. Bisaro D.M. Proc. Natl. Acad. Sci. U. S. A. 1991; 88: 8029-8033Crossref PubMed Scopus (288) Google Scholar, 4.Heyraud F. Matzeit V. Kammann M. Schaefer S. Schell J. Gronenborn B. EMBO J. 1993; 12: 4445-4452Crossref PubMed Scopus (88) Google Scholar) and transcription (5.Sunter G. Gardiner W.E. Bisaro D.M. Virology. 1989; 170: 243-250Crossref PubMed Scopus (53) Google Scholar, 6.Sunter G. Bisaro D.M. Virology. 1989; 173: 647-655Crossref PubMed Scopus (47) Google Scholar). Geminiviruses do not encode their own polymerases and, instead, rely on host enzymes for viral DNA and RNA synthesis. These characteristics make geminiviruses excellent model systems for studying plant DNA replication and transcription mechanisms. The geminivirus, tomato golden mosaic virus (TGMV),1 has a bipartite genome that encodes seven open reading frames that are divergently transcribed. The 5′-intergenic region separating the transcription units is nearly identical between the two DNA components and includes the plus strand origin of replication (7.Lazarowitz S.G. Wu L.C. Rogers S.G. Elmer J.S. Plant Cell. 1992; 4: 799-809Crossref PubMed Scopus (116) Google Scholar, 8.Orozco 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). The promoter for complementary sense transcription overlaps the replication origin (5.Sunter G. Gardiner W.E. Bisaro D.M. Virology. 1989; 170: 243-250Crossref PubMed Scopus (53) Google Scholar,9.Hanley-Bowdoin L. Elmer J.S. Rogers S.G. Plant Cell. 1989; 1: 1057-1067PubMed Google Scholar) and shares some of the cis-elements involved in origin function (10.Eagle P.A. Orozco B.M. Hanley-Bowdoin L. Plant Cell. 1994; 6: 1157-1170PubMed Google Scholar). A directly repeated sequence, GGTAG, is required for origin recognition (11.Fontes 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) and transcriptional repression of the complementary sense (AL1) promoter (10.Eagle P.A. Orozco B.M. Hanley-Bowdoin L. Plant Cell. 1994; 6: 1157-1170PubMed Google Scholar). Similarly, the TATA-box and G-box transcription factor binding sites in the AL1 promoter act as replication enhancer elements (12.Eagle P.A. Hanley-Bowdoin L. J. Virol. 1997; 71: 6947-6955Crossref PubMed Google Scholar). In contrast, three elements in the TGMV intergenic region are necessary for origin function but have little or no effect on AL1 promoter activity. A hairpin structure with a 9-base pair loop sequence that is conserved among all geminiviruses is essential for replication and contains the cleavage site for initiating plus strand DNA synthesis (4.Heyraud F. Matzeit V. Kammann M. Schaefer S. Schell J. Gronenborn B. EMBO J. 1993; 12: 4445-4452Crossref PubMed Scopus (88) Google Scholar, 13.Laufs 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 (259) Google Scholar, 14.Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar). A conserved sequence between the AL1 binding site and the hairpin, the AG-motif, is also required for replication (8.Orozco 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). The third element, the CA motif, is located outside of the minimal origin but its deletion reduced replication 20-fold (8.Orozco 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). The role of the AG- and CA-motifs in TGMV origins is not known, but one possibility is that they bind host factors that facilitate initiation of plus strand DNA replication. 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 (15.Elmer 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, 16.Sunter G. Hartitz M.D. Hormuzdi S.G. Brough C.L. Bisaro D.M. Virology. 1990; 179: 69-77Crossref PubMed Scopus (167) Google Scholar) (AL1 homologues are also designated C1 or Rep.) AL1 is a multifunctional protein that mediates both virus-specific recognition of its cognate origin (17.Fontes 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) and transcriptional repression by binding to the directly repeated sequence in the intergenic region (10.Eagle P.A. Orozco B.M. Hanley-Bowdoin L. Plant Cell. 1994; 6: 1157-1170PubMed Google Scholar, 12.Eagle P.A. Hanley-Bowdoin L. J. Virol. 1997; 71: 6947-6955Crossref PubMed Google Scholar). AL1 initiates and terminates plus strand replication (13.Laufs 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 (259) Google Scholar, 14.Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar, 18.Heyraud-Nitschke F. Schumacher S. Laufs J. Schaefer S. Schell J. Gronenborn B. Nucleic Acids Res. 1995; 23: 910-916Crossref PubMed Scopus (142) Google Scholar) and induces the accumulation of a host replication factor, proliferating cell nuclear antigen, in infected cells (19.Nagar S. Pedersen T.J. Carrick K. Hanley-Bowdoin L. Robertson D. Plant Cell. 1995; 7: 705-719Crossref PubMed Scopus (156) Google Scholar). Recombinant AL1 specifically binds double-stranded DNA (11.Fontes 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, 20.Fontes E.P.B. Luckow V.A. Hanley-Bowdoin L. Plant Cell. 1992; 4: 597-608Crossref PubMed Scopus (136) Google Scholar), cleaves and ligates single-stranded DNA in the invariant sequence of the hairpin loop (14.Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar, 21.Laufs J. Schumacher S. Geisler N. Jupin I. Gronenborn B. FEBS Lett. 1995; 377: 258-262Crossref PubMed Scopus (67) Google Scholar), and hydrolyzes ATP (22.Desbiez 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, 23.Orozco 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 also interacts with itself (23.Orozco 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 viral replication enhancer protein AL3 (24.Settlage S.B. Miller B. Hanley-Bowdoin L. J. Virol. 1996; 70: 6790-6795Crossref PubMed Google Scholar), and a maize homologue of the cell cycle regulatory protein, retinoblastoma (25.Ach 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). We previously mapped the TGMV AL1 domains for double-stranded DNA binding, single-stranded DNA cleavage and ligation, and AL1 oligomerization (23.Orozco 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, 26.Orozco B.M. Hanley-Bowdoin L. J. Biol. Chem. 1998; 273: 24448-24456Abstract Full Text Full Text PDF PubMed Scopus (81) Google Scholar). The DNA cleavage/ligation domain was located to the first 120 amino acids, and the oligomerization domain was mapped between amino acids 120 and 181. DNA binding activity required amino acids 1–130 for protein-DNA contacts and the AL1 oligomerization domain. Because of its importance in AL1 function, we have further characterized the sequences required for oligomerization in vitro and assessed the impact of site-directed mutations in the domain in vivo. Constructs are listed in Table I. The plasmid pNSB148, which contains the AL1 coding sequence in a pUC118-background, was used as the template for site-directed mutagenesis (27.Kunkel T.A. Proc. Natl. Acad. Sci. U. S. A. 1985; 82: 482-492Google Scholar). The oligonucleotide primers and resulting clones are also listed in TableI. DNA fragments containing the mutations were verified by DNA sequence analysis. Plant expression cassettes for mutant AL1 proteins were generated by subcloningSalI/NcoI fragments (TGMV A position 2442 and 2059) from the mutant clones into the same sites in the wild type AL1 plant expression cassette pMON1549 (11.Fontes 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 35S promoter with a duplicated enhancer region and the pea E9 rbcS 3′-end.Table IAL1 mutationsMutationOligonucleotideBaculovirus vectorYeast GAL4-ADPlant expressionWild typeN/ApMON1680pNSB809pMON1549FQ118CACTTCGACCGTCGACCGCGGCTTCTCCCCAN/ApNSB872pNSB866D120CACTTCGGCCGGCGACCGCGGCTTCTCCCCAN/ApNSB871pNSB865RS-R125GCAACCTCCTgcAGCggccgcACCGTCGACCTGGAN/ApNSB786pNSB695QT130CAGCGTCGTTgctaGcTgcGCAACCTCCTCTAGCAN/ApNSB788pNSB696ND133CTGCTGCAGCGgCcgcAGATGTTTGGCAApNSB603PNSB790pNSB670E–N140GGAAGAAGCAgcTAACGCggCcGCTGCAGCGTCGTpNSB604PNSB893pNSB640KEE146TCTGCAGGGCTgCggCcgcGGAAGAAGCATTTAApNSB605PNSB894pNSB641REK154TTCTGGGATTgcggCcgcAATTATCTGCAGGGpNSB606pNSB759pNSB671EKY159GAACTGAAATAAAgcggccgCTGGGATTTTCTCTCpNSB607pNSB760pNSB672Q-HN165GCTATTTAGAgcGgcGAACgcAAATAAATATTTTTCTGGGATpNSB608pNSB761pNSB698N-DR172ATCAAATATCgcAgCTAgcgcGCTATTTAGATTGTGpNSB609pNSB762pNSB707K–E179GAAGCCATGGcgCcGGAGTCgcATCAAATATCCpNSB610pNSB763pNSB697 Open table in a new tab Baculovirus vectors were generated for expression of mutant and truncated AL1 proteins in insect cells. Expression vectors coding for mutant AL1 proteins were made by subcloningBglII/BamHI inserts from the mutant plant expression cassettes into the BamHI site of pMON27025 (28.Luckow V.A. Lee S.C. Barry G.F. Olins P.O. J. Virol. 1993; 67: 4566-4579Crossref PubMed Google Scholar). Expression vectors for the truncated proteins, AL1119–352(pNSB516), AL11–120 (pNSB388), and AL11–180(pNSB517), have been described previously (23.Orozco 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 N-terminal truncations, AL1134–352 and AL1147–352, were generated by inserting a double-stranded oligonucleotide containing anSphI site into the NotI site of pNSB593 and pNSB595 to create in-frame start codons. AL1160–352 was created by inserting an SphI linker with a start codon (New England Biolabs, Beverly, MA) into the SspI site of pMON1539 (29.Hanley-Bowdoin L. Elmer J.S. Rogers S.G. Proc. Natl. Acad. Sci. U. S. A. 1990; 87: 1446-1450Crossref PubMed Scopus (84) Google Scholar). SphI/BamHI fragments from the resulting clones were inserted into the same sites of the baculovirus vector, pNSB448 (23.Orozco 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), to give pNSB803 (AL1134–352), pNSB876 (AL1147–352), and pNSB633 (AL1160–352). The C-terminal truncation, AL11–158 (pNSB646), was generated by digesting pMON1539 with NdeI and SspI, repairing with Klenow, and subcloning into the filled BamHI site of pMON27025 to create an in-frame stop codon. The AL11–168 truncation, pNSB708, was created by inserting anXbaI linker into the repaired BssHII of pNSB609, generating an in-frame stop codon. Yeast expression cassettes were generated using the pAS1–1 and pACT2 vectors from CLONTECH (Palo Alto, CA). TheBamHI/NdeI fragment of pMON1539 was cloned into the same sites of pAS2–1 to give pNSB736, which contained the GAL4 DNA binding domain fused to wild type AL1 sequences. The ends of the sameBamHI/NdeI fragment were repaired with Klenow and cloned into the SmaI site of pACT2 to give pNSB735. TheAatII/BamHI fragment of pNSB735 was then replaced with the AatII/BamHI fragment from pMON1549. The resulting clone, pNSB809, contained the GAL4 activation domain (AD) fused to wild type AL1 sequences. Mutant AL1 yeast expression cassettes were created by replacing the wild typeAatII/BamHI fragment of pNSB735 with mutantAatII/BamHI fragments from the corresponding plant expression cassettes. Protoplasts were isolated from Nicotiana tabacum (BY-2) orNicoxiana benthamiana suspension cells, electroporated, and cultured according to published methods (11.Fontes 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). For replication assays, N. tabacum transfections included 15 μg each of replicon DNA containing a partial tandem copy of TGMV B (pTG1.4B, Ref. 17.Fontes 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 plant expression cassette, and an AL3 plant expression cassette (pNSB46, Ref. 11.Fontes 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). For the interference assays, 2 μg of replicon DNA containing a partial tandem copy of TGMV A (pMON1565, Ref. 14.Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar) was cotransfected with 40 μg of mutant AL1 expression cassette or the empty expression vector (pMON921, Ref. 11.Fontes 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 post-transfection and analyzed for double- and single-stranded viral DNA accumulation by DNA gel blot hybridization (11.Fontes 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 viral DNA was quantified by phosphorimager analysis in a minimum of three independent experiments. For transcriptional repression assays, N. benthamianaprotoplasts were transfected with 15 μg of luc reporter construct (pNSB114), 15 μg of AL1 expression cassette, and 36 μg of sheared salmon sperm DNA (10.Eagle P.A. Orozco B.M. Hanley-Bowdoin L. Plant Cell. 1994; 6: 1157-1170PubMed Google Scholar). Luciferase activity in total soluble protein extracts was measured 36 h post-transfection and standardized for protein concentration. Repression was determined as the ratio of Luc activity in the absence versus the presence of AL1. Each expression cassette was assayed in triplicate in at least three independent experiments. Recombinant proteins were produced inSpodoptera frugiperda Sf9 cells using a baculovirus expression system according to published protocols (14.Orozco B.M. Hanley-Bowdoin L. J. Virol. 1996; 270: 148-158Crossref Google Scholar, 24.Settlage S.B. Miller B. Hanley-Bowdoin L. J. Virol. 1996; 70: 6790-6795Crossref PubMed Google Scholar). Protein extracts from cells co-expressing authentic and GST-AL1 fusion proteins were assayed for AL1 oligomerization by co-purification on glutathione-Sepharose (24.Settlage S.B. Miller B. Hanley-Bowdoin L. J. Virol. 1996; 70: 6790-6795Crossref PubMed Google Scholar). Co-purification was monitored by SDS-polyacrylamide electrophoresis followed by transfer to nitrocellulose membrane (Schleicher and Schuell) and immunoblotting using the ECL detection system (Amersham Pharmacia Biotech). Primary antibodies were rabbit polyclonal anti-GST (Upstate Biotechnology Inc.) and anti-AL1 antisera (24.Settlage S.B. Miller B. Hanley-Bowdoin L. J. Virol. 1996; 70: 6790-6795Crossref PubMed Google Scholar). The Saccharomyces cerevisiae strain Y187 (MATα,ura3–52, his3–200, ade 2–101,trp 1–901, leu 2–3, 112,gal4Δ, met −, gal80Δ,URA3::GAL1 UAS-GAL1 TATA-lacZ) was transformed using lithium acetate/polyethylene glycol (30.Geitz D. St. Jean A. Woods R.A. Schiesti R.H. Nucleic Acids Res. 1992; 20: 1425Crossref PubMed Scopus (2895) Google Scholar). The DNAs were pNSB736, which expresses the GAL4 binding domain-wild type AL1 fusion, and either pNSB809, which produces the GAL4 AD-wild type AL1 protein, or the equivalent cassettes corresponding to the GAL4 AD-AL1 mutants. For β-galactosidase assays, yeast transformants were grown to an A 600 of 0.5 in 3 ml of synthetic dropout medium lacking tryptophan and leucine (31.Sherman F. Fink G.R. Hicks J.B. Laboratory Course Manual for Methods in Yeast Genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY1986Google Scholar). Yeast were pelleted at 1000 × g for 5 min, rinsed with Z buffer (0.1m NaPO4, pH 7, 10 mm KCl, 1 mm MgSO4, 40 mmβ-mercaptoethanol) (31.Sherman F. Fink G.R. Hicks J.B. Laboratory Course Manual for Methods in Yeast Genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY1986Google Scholar), and resuspended in 300 μl of Z buffer. The cells were subjected to three freeze/thaw cycles in liquid nitrogen and centrifuged at 5000 × g for 2 min. The supernatant (150 μl) was assayed for β-galactosidase activity in a total reaction volume of 250 μl using the substrateo-nitrophenyl β-d-galactopyranoside, as described by CLONTECH. Accumulation of theo-nitrophenol product was measured atA 420 using a BioKinetics microplate reader (Bio-Tek Instrument Inc., Winooski, VT). Protein concentrations were measured by Bradford assays (Bio-Rad). The enzyme-specific activity (1 unit = 1.0 μm product/min at pH7.3 at 37 °C) resulting from interaction between two-hybrid cassettes carrying wild type AL1 sequences was determined using purified β-galactosidase (Sigma) as the standard. The relative activities of the mutants were normalized against the wild type AL1 interaction level, which was set to 100%. The β-galactosidase specific activity for wild type and mutant AL1 proteins was adjusted for background from pNSB736 alone. The different constructs were tested in a minimum of two experiments, each of which assayed four independent transformants for each construct. For immunoblot analysis, individual yeast transformants were grown in 5 ml of medium containing 1% yeast extract, 2% bacto-peptone, 2% glucose, pH 5.8 (31.Sherman F. Fink G.R. Hicks J.B. Laboratory Course Manual for Methods in Yeast Genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY1986Google Scholar) to an A 600 of 1. An equal volume of crushed ice was added and the culture was centrifuged at 1000 × g for 5 min. The resulting pellet was washed once with ice cold water and resuspended in 80 μl of modified radioimmune precipitation buffer (150 mm NaCl, 1% (v/v) Nonidet P-40, 0.5% (w/v) sodium deoxycholate, 50 mmTris-HCl, pH 7.5 (32.Harlow E. Lane D. Antibodies, A Laboratory Manual. Cold Spring Harbor Press, Cold Spring Harbor, NY1988Google Scholar), containing 1% (w/v) SDS) and protease inhibitors (6 μg/ml pepstatin A, 10 μg/ml leupeptin, 20 μg/ml aprotinin, 8 mm benzamidine, 1 mmphenylmethylsulfonyl fluoride). Glass beads (40 μl, 425–600 μm, Sigma) were added and the sample was vortexed at maximum speed for four 30-s intervals separated by 2-min intervals on ice. The sample was then centrifuged at 5000 × g for 2 min at 4 °C. The supernatant was recovered, and the protein concentration was determined using Bradford assays. Total protein (100 μg) was resolved on 12% polyacrylamide/SDS gels and analyzed by immunoblotting using a GAL4 AD monoclonal antibody at 0.4 μg/ml (CLONTECH). The domains for TGMV AL1 DNA binding and DNA cleavage/ligation activities are well defined, and key structural and sequence motifs have been identified for these functions (23.Orozco 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, 26.Orozco B.M. Hanley-Bowdoin L. J. Biol. Chem. 1998; 273: 24448-24456Abstract Full Text Full Text PDF PubMed Scopus (81) Google Scholar), whereas the AL1 oligomerization domain has only been broadly located to the center of the protein (23.Orozco 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). In this paper, closely spaced N- and C-terminal truncations were generated to define the limits of the AL1 oligomerization domain (Fig.1 A). A GST fusion corresponding to full-length AL1 (GST-AL1) was co-expressed with the truncated AL1 proteins in baculovirus-infected insect cells, and protein complexes were purified on glutathione-Sepharose resin. Total extracts and purified proteins were resolved by SDS-polyacrylamide gel electrophoresis, and proteins were visualized by immunoblotting with AL1 and GST polyclonal antisera. As reported previously (23.Orozco 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 C-terminal truncation AL11–180 (Fig. 1 B,lanes 3 and 6) copurified with full-length GST-AL1. Further deletion of the C terminus to amino acid 168 (lanes 2 and 5) or 158 (lanes 1 and4) abolished interactions with GST-AL1, demonstrating that the C-terminal limit of the oligomerization domain is between position 168 and 180. The N-terminal truncations to amino acids 134 (Fig.1 C, lanes 3 and 6), 147 (lanes 2 and 5), and 160 (lanes 1 and 4) showed a gradual disappearance of interaction with GST-AL1. AL1134–352 consistently displayed interactions with GST-AL1, whereas AL1147–352 and AL1160–352interactions varied between weak to background levels, making it more difficult to define the N-terminal limit. Contacts outside the oligomerization domain may contribute to complex stability or multimerization and account for the low level interactions observed with AL1147–352 and AL1160–352. To address this possibility, we asked whether full-length AL1 copurified when only the oligomerization domain was fused to GST (GST-AL1119–180). Full-length AL1 interacted with GST-AL1119–180 but not with GST alone (Fig.2 B, lanes 1 and2), demonstrating that amino acids 119–180 are sufficient for oligomerization. We then examined the abilities of the N-terminal AL1 truncations to bind GST-AL1119–180. In this assay, deletion to positions 119 (Fig. 1 D, lanes 1 and5) and 134 (lanes 2 and 6) did not affect oligomerization, whereas further deletion to positions 147 (lanes 3 and 7) and 160 (lanes 4 and8) abolished interactions with GST-AL1119–180. Together, these results showed that AL1 amino acids 134–180 contain the oligomerization domain and that sequences outside the domain contribute stabilizing contacts. Alanine substitutions were generated in conserved charged or hydrophobic residues within the oligomerization domain to identify key amino acids that contribute to AL1 interactions (Fig.3, the mutations are designated by the corresponding wild type sequence and the position of the last amino acid that was altered; dashes indicate amino acids that were not changed). Alanine was selected because it is structurally neutral and should not interfere with normal protein folding. The mutations are within a region that includes a pair of predicted α-helices (26.Orozco B.M. Hanley-Bowdoin L. J. Biol. Chem. 1998; 273: 24448-24456Abstract Full Text Full Text PDF PubMed Scopus (81) Google Scholar) and downstream sequences required for oligomerization. All of the mutant AL1 proteins co-purified with GST-AL1 on glutathione resin when co-expressed in insect cells (Fig. 2 A), showing that they formed stable complexes with the wild type protein. Similar results were observed when both the test and GST fusion proteins carried the mutations (data not shown). In contrast, when interactions between the mutant AL1 proteins and GST-AL1119–180 were examined mutant EKY159 (Fig. 2 B, lane 6) was defective for AL1 interactions. Thus, sequences outside of the oligomerization domain in the full-length AL1 masked the effect of the EKY159 mutation in Fig.2 A, which is consistent with our previous conclusion that sequences outside the oligomerization domain stabilize AL1 interactions. The oligomerization mutant, EKY159, was assayed with truncated GST-AL1 proteins to locate the stabilizing region. As shown above, EKY159 bound full-length GST-AL1 (Fig. 2 C,lanes 1 and 5) but not GST-AL1119–180 (lanes 4 and 8). EKY159 also bound an N-terminal truncation, GST-AL1119–352(lanes 3 and 7), whereas no interaction was detected with a C-terminal truncation, GST-AL11–180(lanes 2 and 6), demonstrating that the AL1 C terminus contributes stabilizing contacts. The quantitative impact of each mutation on AL1 oligomerization was measured using a yeast two-hybrid system. Expression cassettes for wild type or mutant AL1 fused to the GAL4 AD were cotransformed into yeast with a cassette for wild type AL1 fused to the GAL4 DNA binding domain. Activation of a GAL4-responsive promoter driving a lacZreporter was assayed by measuring β-galactosidase activity in total soluble protein extracts. In extracts from yeast cotransfected with AD and binding domain cassettes carrying wild type AL1 sequences, 142 mu/mg total protei DA - 2000/3/3/ PY - 2000/3/3/ DO - 10.1074/jbc.275.9.6114 VL - 275 IS - 9 SP - 6114-6122 SN - 0021-9258 ER - TY - JOUR TI - Temporal dynamics of Phytophthora blight on bell pepper in relation to the mechanisms of dispersal of primary inoculum of Phytophthora capsici in soil AU - Sujkowski, LS AU - Parra, GR AU - Gumpertz, ML AU - Ristaino, JB T2 - PHYTOPATHOLOGY AB - The effect of components of primary inoculum dispersal in soil on the temporal dynamics of Phytophthora blight epidemics in bell pepper was evaluated in field and growth-chamber experiments. Phytophthora capsici may potentially be dispersed by one of several mechanisms in the soil, including inoculum movement to roots, root growth to inoculum, and root-to-root spread. Individual components of primary inoculum dispersal were manipulated in field plots by introducing (i) sporangia and mycelia directly in soil so that all three mechanisms of dispersal were possible, (ii) a plant with sporulating lesions on the soil surface in a plastic polyvinyl chloride (PVC) tube so inoculum movement to roots was possible, (iii) a wax-encased peat pot containing sporangia and mycelia in soil so root growth to inoculum was possible, (iv) a wax-encased peat pot containing infected roots in soil so root-to-root spread was possible, (v) noninfested V8 vermiculite media into soil directly as a control, or (vi) wax-encased noninfested soil as a control. In 1995 and 1996, final incidence of disease was highest in plots where sporangia and mycelia were buried directly in soil and all mechanisms of dispersal were operative (60 and 32%) and where infected plants were placed in PVC tubes on the soil surface and inoculum movement to roots occurred with rainfall (89 and 23%). Disease onset was delayed in 1995 and 1996, and final incidence was lower in plants in plots where wax-encased sporangia (6 and 22%) or wax-encased infected roots (22%) were buried in soil and root growth to inoculum or root-to-root spread occurred. Incidence of root infections was higher over time in plots where inoculum moved to roots or all mechanisms of dispersal were possible. In growth-chamber studies, ultimately all plants became diseased regardless of the dispersal mechanism of primary inoculum, but disease onset was delayed when plant roots had to grow through a wax layer to inoculum or infected roots in tension funnels that contained small volumes of soil. Our data from both field and growth-chamber studies demonstrate that the mechanism of dispersal of the primary inoculum in soil can have large effects on the temporal dynamics of disease. DA - 2000/2// PY - 2000/2// DO - 10.1094/phyto.2000.90.2.148 VL - 90 IS - 2 SP - 148-156 SN - 0031-949X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0033958523&partnerID=MN8TOARS KW - root disease KW - spatial dynamics ER - TY - JOUR TI - Nucleocapsid gene-mediated transgenic resistance provides protection against Tomato spotted wilt virus epidemics in the field AU - Herrero, S. AU - Culbreath, A. K. AU - Csinos, A. S. AU - Pappu, H. R. AU - Rufty, R. C. AU - Daub, M. E. T2 - Phytopathology AB - ABSTRACT Transformation of plants with the nucleocapsid (N) gene of Tomato spotted wilt tospovirus (TSWV) provides resistance to disease development; however, information is lacking on the response of plants to natural inoculum in the field. Three tobacco cultivars were transformed with the N gene of a dahlia isolate of TSWV (TSWV-D), and plants were evaluated over several generations in the greenhouse. The resistant phenotype was more frequently observed in 'Burley 21' than in 'KY-14' or 'K-326', but highly resistant 'Burley 21' transgenic lines were resistant to only 44% of the heterologous TSWV isolates tested. Advanced generation (R(3) and R(4)) transgenic resistant lines of 'Burley 21' and a 'K-326' F(1) hybrid containing the N genes of two TSWV isolates were evaluated in the field near Tifton, GA, where TSWV is endemic. Disease development was monitored by symptom expression and enzyme-linked immunosorbent assay (ELISA) analysis. Whereas incidence of TSWV infection in 'Burley 21' susceptible controls was 20% in 1996 and 62% in 1997, the mean incidence in transgenic lines was reduced to 4 and 31%, respectively. Three transgenic 'Burley 21' lines were identified that had significantly lower incidence of disease than susceptible controls over the two years of the study. In addition, the rate of disease increase at the onset of the 1997 epidemic was reduced for all the 'Burley 21' transgenic lines compared with the susceptible controls. The 'K-326' F(1) hybrid was as susceptible as the 'K-326' nontransformed control. ELISA analysis demonstrated that symptomless plants from the most resistant 'Burley 21' transgenic lines accumulated detectable nucleocapsid protein, whereas symptomless plants from more susceptible lines did not. We conclude that transgenic resistance to TSWV is effective in reducing incidence of the disease in the field, and that accumulation of transgene protein may be important in broad-spectrum resistance. DA - 2000/// PY - 2000/// DO - 10.1094/phyto.2000.90.2.139 VL - 90 IS - 2 SP - 139-147 ER - TY - JOUR TI - Lignin structure in a mutant pine deficient in cinnamyl alcohol dehydrogenase AU - Lapierre, C AU - Pollet, B AU - MacKay, JJ AU - Sederoff, RR T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - Cinnamyl alcohol dehydrogenase (CAD) activity is deficient in loblolly pine (Pinus taeda L.) harboring a mutated allele of the cad gene (cad-n1). We compared lignin structure of CAD-deficient and wild-type pines, both types segregating within full-sib families obtained by controlled crosses. The type and frequency of lignin building units and distribution of interunit bonds were determined from the GC-MS analysis of thioacidolysis monomers and dimers. While the lignin content was only slightly reduced, the lignin structure was dramatically modified by the mutation in both mature and juvenile trees. Lignins from CAD-deficient pine displayed unusually high levels of coniferaldehyde and dihydroconiferyl alcohol. In addition, biphenyl and biphenyl ether bonds were in large excess in these abnormal lignins. These results suggest that the CAD-deficient pines efficiently compensate for the shortage in normal lignin precursors by utilizing nontraditional wall phenolics to construct unusual lignins particularly enriched in resistant interunit bonds. DA - 2000/6// PY - 2000/6// DO - 10.1021/jf991398p VL - 48 IS - 6 SP - 2326-2331 SN - 0021-8561 KW - lignification KW - altered lignin structure KW - pine (Pinus taeda L.) KW - thioacidolysis KW - dihydroconiferyl alcohol ER - TY - JOUR TI - Inositol signaling and plant growth AU - Stevenson, JM AU - Pepera, IY AU - Heilmann, I AU - Persson, S AU - Boss, WF T2 - TRENDS IN PLANT SCIENCE AB - Living organisms have evolved to contain a wide variety of receptors and signaling pathways that are essential for their survival in a changing environment. Of these, the phosphoinositide pathway is one of the best conserved. The ability of the phosphoinositides to permeate both hydrophobic and hydrophilic environments, and their diverse functions within cells have contributed to their persistence in nature. In eukaryotes, phosphoinositides are essential metabolites as well as labile messengers that regulate cellular physiology while traveling within and between cells. The stereospecificity of the six hydroxyls on the inositol ring provides the basis for the functional diversity of the phosphorylated isomers that, in turn, generate a selective means of intracellular and intercellular communication for coordinating cell growth. Although such complexity presents a difficult challenge for bench scientists, it is ideal for the regulation of cellular functions in living organisms. DA - 2000/6// PY - 2000/6// DO - 10.1016/S1360-1385(00)01652-6 VL - 5 IS - 6 SP - 252-258 SN - 1878-4372 ER - TY - JOUR TI - Genetic discontinuity revealed by chloroplast microsatellites in eastern North American Abies (Pinaceae) AU - Clark, CM AU - Wentworth, TR AU - DM O'Malley, T2 - AMERICAN JOURNAL OF BOTANY AB - Development of conservation strategies for Fraser fir ( Abies fraseri) in the southern Appalachian Mountains depends in part on recognition of the extent to which Fraser fir is genetically distinct from the closely related balsam ( A. balsamea ) and intermediate ( A. balsamea var. phanerolepis ) fir. These sibling species have exhibited intergrading, clinal variation in morphological, chemical, and genetic characteristics in prior research. Chloroplast microsatellite markers were polymerase chain reaction amplified from genomic DNA samples of 78 individuals representing the geographic ranges of Fraser, balsam, and intermediate fir. Gene diversity levels at two loci ranged among taxa from 0.65 to 0.84. Allele frequencies demonstrated significant differentiation among taxa, with R ST values of 0.36 and 0.10. Haplotype diversity and D 2 SH were highest for balsam fir and lowest for intermediate fir. A haplotype network analysis based on allele size distribution for the two loci revealed two distinct clusters of haplotypes and population‐specific haplotypes. Ninety‐two percent of the haplotypes in one cluster were from balsam fir and intermediate fir, and 84% of the haplotypes in the other cluster were from Fraser fir and intermediate fir. The genetic differentiation of chloroplast DNA markers provides justification for the recognition of Fraser fir as a distinct Management Unit (MU) for conservation purposes, regardless of its taxonomic classification. DA - 2000/6// PY - 2000/6// DO - 10.2307/2656885 VL - 87 IS - 6 SP - 774-782 SN - 1537-2197 KW - Abies KW - chloroplast DNA KW - chloroplast haplotypes KW - chloroplast microsatellites KW - chloroplast SSRs KW - conservation KW - Fraser fir KW - Pinaceae ER - TY - JOUR TI - Efficient synthesis of monoacyl dipyrromethanes and their use in the preparation of sterically unhindered trans-porphyrins AU - Rao, PD AU - Littler, BJ AU - Geier, GR AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - The condensation of an aldehyde with a dipyrromethane bearing a sterically unhindered aryl substituent at the 5-position typically results in low yield and a mixture of porphyrin products derived from acidolytic scrambling. We have developed a concise nonscrambling synthesis of such trans-porphyrins that takes advantage of the availability of multigram quantities of dipyrromethanes. This route involves the selective monoacylation of the dipyrromethanes with a pyridyl thioester, reduction of the monoacyl dipyrromethane to the corresponding carbinol, and self-condensation of the carbinol to form the porphyrin. The monoacylation procedure has wide scope as demonstrated by the preparation of a set of 15 diverse monoacyl dipyrromethanes in good yield at the multigram scale. The dipyrromethanecarbinol self-condensation reaction is extremely rapid (<3 min) under mild room-temperature conditions and affords the trans-porphyrin in 16-28% yield. Analysis by laser-desorption mass spectrometry (LD-MS) of samples from the crude reaction mixture revealed no scrambling within the limit of detection (1 part in 100). The self-condensation is compatible with a range of electron-withdrawing or -releasing substituents as well as substituents for building block applications (TMS-ethyne, ethyne, iodo, ester). The absence of any detectable scrambling in the self-condensation enables a simple purification. The synthesis readily affords gram quantities of pure, sterically unhindered trans-porphyrins in a process involving minimal chromatography. DA - 2000/2/25/ PY - 2000/2/25/ DO - 10.1021/jo9915473 VL - 65 IS - 4 SP - 1084-1092 SN - 0022-3263 ER - TY - JOUR TI - A survey of acid catalysts for use in two-step, one-flask syntheses of meso-substituted porphyrinic macrocycles AU - Geier, GR AU - Ciringh, Y AU - Li, FR AU - Haynes, DM AU - Lindsey, JS T2 - ORGANIC LETTERS AB - [reaction: see text] Diverse Lewis acids and Bronsted acids were examined in the two-step, one-flask synthesis of meso-tetraphenylporphyrin, N-confused tetraphenylporphyrin, and tetraphenylsapphyrin. The scope of acid catalysis was found to be very broad, with 35 of 45 acids providing TPP in yields ranging from 5% to 58%. NC-TPP was also widely observed in yields of 1-40%, and TPS was infrequently observed in yields of <1%. Additionally, conditions were found for direct preparation of magnesium TPP and copper TPP. DA - 2000/6/15/ PY - 2000/6/15/ DO - 10.1021/ol005917h VL - 2 IS - 12 SP - 1745-1748 SN - 1523-7060 ER - TY - JOUR TI - A putative role for the tomato genes DUMPY and CURL-3 in brassinosteroid biosynthesis and response AU - Koka, CV AU - Cerny, RE AU - Gardner, RG AU - Noguchi, T AU - Fujioka, S AU - Takatsuto, S AU - Yoshida, S AU - Clouse, SD T2 - PLANT PHYSIOLOGY AB - Abstract Thedumpy (dpy) mutant of tomato (Lycopersicon esculentum Mill.) exhibits short stature, reduced axillary branching, and altered leaf morphology. Application of brassinolide and castasterone rescued the dpyphenotype, as did C-23-hydroxylated, 6-deoxo intermediates of brassinolide biosynthesis. The brassinolide precursors campesterol, campestanol, and 6-deoxocathasterone failed to rescue, suggesting thatdpy may be affected in the conversion of 6-deoxocathasterone to 6-deoxoteasterone, similar to the Arabidopsisconstitutive photomorphogenesis and dwarfism(cpd) mutant. Measurements of endogenous brassinosteroid levels by gas chromatography-mass spectrometry were consistent with this hypothesis. To examine brassinosteroid-regulated gene expression in dpy, we performed cDNA subtractive hybridization and isolated a novel xyloglucan endotransglycosylase that is regulated by brassinosteroid treatment. The curl-3(cu-3) mutant (Lycopersicon pimpinellifolium [Jusl.] Mill.) shows extreme dwarfism, altered leaf morphology, de-etiolation, and reduced fertility, all strikingly similar to the Arabidopsis mutantbrassinosteroid insensitive 1 (bri1). Primary root elongation of wild-type L. pimpinellifoliumseedlings was strongly inhibited by brassinosteroid application, whilecu-3 mutant roots were able to elongate at the same brassinosteroid concentration. Moreover, cu-3 mutants retained sensitivity to indole-3-acetic acid, cytokinins, gibberellin, and abscisic acid while showing hypersensitivity to 2,4-dichlorophenoxyacetic acid in the root elongation assay. Thecu-3 root response to hormones, coupled with itsbri1-like phenotype, suggests that cu-3may also be brassinosteroid insensitive. DA - 2000/1// PY - 2000/1// DO - 10.1104/pp.122.1.85 VL - 122 IS - 1 SP - 85-98 SN - 0032-0889 ER - TY - JOUR TI - Rational synthesis of meso-substituted porphyrins bearing one nitrogen heterocyclic group AU - Gryko, D AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTRational Synthesis of Meso-Substituted Porphyrins Bearing One Nitrogen Heterocyclic GroupDorota Gryko and Jonathan S. LindseyView Author Information Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204 Cite this: J. Org. Chem. 2000, 65, 7, 2249–2252Publication Date (Web):March 15, 2000Publication History Received23 November 1999Published online15 March 2000Published inissue 1 April 2000https://doi.org/10.1021/jo9918100Copyright © 2000 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views3365Altmetric-Citations74LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (47 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Aldehydes,Condensation,Nitrogen,Pyrroles,Substituents Get e-Alerts DA - 2000/4/7/ PY - 2000/4/7/ DO - 10.1021/jo9918100 VL - 65 IS - 7 SP - 2249-2252 SN - 1520-6904 ER - TY - CHAP TI - Molecular dissection of quantitative traits: new perspectives from populus AU - Wu, R. AU - Li, B. AU - Zeng, Z.-B. T2 - Molecular biology of woody plants A2 - Jain, S. M. A2 - Minocha, S. C. CN - SD403.5 .M66 2000 PY - 2000/// VL - 1 SP - 475-490 PB - Dordrecht; Boston: Kluwer Academic ER - TY - JOUR TI - Impact of forest genetics on sustainable forestry: results from two cycles of loblolly pine breeding in the U.S. AU - Li, B. AU - McKeand, Steven AU - Weir, R. T2 - Journal of Sustainable Forestry DA - 2000/// PY - 2000/// DO - 10.1300/j091v10n01_09 VL - 10 IS - 1/2 SP - 79–85 ER - TY - JOUR TI - Early field growth of loblolly pine rooted cuttings and seedlings AU - Frampton, J. AU - Li, B. AU - Goldfarb, B. T2 - Southern Journal of Applied Forestry DA - 2000/// PY - 2000/// VL - 24 IS - 2 SP - 98-105 ER - TY - JOUR TI - Correlations among amino acid sites in bHLH protein domains: An information theoretic analysis AU - Atchley, WR AU - Wollenberg, KR AU - Fitch, WM AU - Terhalle, W AU - Dress, AW T2 - MOLECULAR BIOLOGY AND EVOLUTION AB - An information theoretic approach is used to examine the magnitude and origin of associations among amino acid sites in the basic helix-loop-helix (bHLH) family of transcription factors. Entropy and mutual information values are used to summarize the variability and covariability of amino acids comprising the bHLH domain for 242 sequences. When these quantitative measures are integrated with crystal structure data and summarized using helical wheels, they provide important insights into the evolution of three-dimensional structure in these proteins. We show that amino acid sites in the bHLH domain known to pack against each other have very low entropy values, indicating little residue diversity at these contact sites. Noncontact sites, on the other hand, exhibit significantly larger entropy values, as well as statistically significant levels of mutual information or association among sites. High levels of mutual information indicate significant amounts of intercorrelation among amino acid residues at these various sites. Using computer simulations based on a parametric bootstrap procedure, we are able to partition the observed covariation among various amino acid sites into that arising from phylogenetic (common ancestry) and stochastic causes and those resulting from structural and functional constraints. These results show that a significant amount of the observed covariation among amino acid sites is due to structural/functional constraints, over and above the covariation arising from phylogenetic constraints. These quantitative analyses provide a highly integrated evolutionary picture of the multidimensional dynamics of sequence diversity and protein structure. DA - 2000/1// PY - 2000/1// DO - 10.1093/oxfordjournals.molbev.a026229 VL - 17 IS - 1 SP - 164-178 SN - 0737-4038 KW - mutual information KW - protein evolution KW - entropy KW - parametric bootstrap KW - helix-loop-helix ER - TY - JOUR TI - Seroprevalence of Ehrlichia canis, Ehrlichia equi, and Ehrlichia risticii in sick dogs from North Carolina and Virginia AU - Suksawat, J. AU - Hegarty, B. C. AU - Breitschwerdt, Edward T2 - Journal of Veterinary Internal Medicine AB - Ehrlichia canis, E equi , and E risticii seroprevalence was determined by microimmunofluorescent antibody testing (IFA) in a sequential population of 1,845 sick dogs admitted during a 1‐year period to the North Carolina State University Veterinary Teaching Hospital. A seroreactor was defined by a reciprocal IFA titer of ≥80 to E canis, E equi , or E risticii antigens. Of the 48 IFA seroreactors, 44 dogs were seroreactive to E canis , 21 to E equi , and 0 to E risticii. Seventeen dogs reacted to both E canis and E equi antigens. There was concordance of E canis IFA and western immunoblot (WI) test results for 36/44 dogs. Because of cross‐reactivity of E canis sera with E equi antigens, WI was of less utility to confirm E equi exposure. After elimination of E canis seroreactors, there was concordance of 2/4 E equi IFA and WI test results. Based upon a retrospective review of medical records, ehrlichiosis was diagnosed in 10/48 (21%) IFA seroreactive dogs, 9 of which were confirmed positive by WI. Of the remaining 38 IFA seroreactors, 29 also were confirmed by E canis or E equi WI. These results indicate that (1) ehrlichiosis was not diagnosed in the majority of serologically confirmed cases, (2) based upon E canis and E equi WI analysis, IFA testing was not specific (21% false positive), (3) E canis sera cross‐react with E equi antigens, and (4) serologic evidence of E risticii infection was lacking in the dog population studied. DA - 2000/// PY - 2000/// DO - 10.1111/j.1939-1676.2000.tb01499.x VL - 14 IS - 1 SP - 50–55 ER - TY - JOUR TI - Prevalence of Bartonella henselae Antibody in Florida Panthers AU - Rotstein, David S. AU - Taylor, Sharon K. AU - Bradley, Julie AU - Breitschwerdt, Edward B. T2 - Journal of Wildlife Diseases AB - Serum samples from 28 free-ranging Florida panthers (Puma concolor coryi) and seven mountain lions from Texas (P. concolor stanleyana) living in south Florida (USA) between 1997 to 1998 were tested for antibodies to Bartonella henselae. Twenty percent (7/35) of the samples were reactive to B. henselae antisera with a subspecies prevalence of 18% (5/ 28) for Florida panthers and 28% (2/7) for cougars from Texas (USA). There was not a significant sex related difference in infection rates among the Florida panthers. Antibody prevalence was higher in panthers <2-yr of age (40%) compared to panthers >2-yr (13%). Compared to studies of antibody prevalence in mountain lions (P. concolor) from California (USA), overall seroprevalence was lower as was prevalence in panthers >2-yr-old. However, the seroprevalence in animals <2-yr from southern Florida was similar to prevalences reported in mountain lions or domestic felids in California. DA - 2000/1// PY - 2000/1// DO - 10.7589/0090-3558-36.1.157 VL - 36 IS - 1 SP - 157-160 J2 - Journal of Wildlife Diseases LA - en OP - SN - 0090-3558 UR - http://dx.doi.org/10.7589/0090-3558-36.1.157 DB - Crossref KW - Bartonellosis KW - Bartonella henselae KW - Florida panther KW - mountain lion KW - Puma concolor coryi KW - Puma concolor stanleyana KW - serology ER - TY - JOUR TI - Molecular evolution of the GATA family of transcription factors: Conservation within the DNA-binding domain AU - Lowry, JA AU - Atchley, WR T2 - JOURNAL OF MOLECULAR EVOLUTION DA - 2000/2// PY - 2000/2// DO - 10.1007/s002399910012 VL - 50 IS - 2 SP - 103-115 SN - 1432-1432 KW - GATA KW - transcription factor KW - zinc finger KW - DNA binding domain KW - phylogeny KW - Boltzmann entropy KW - predictive motif ER - TY - JOUR TI - Interspecific evolution in plant microsatellite structure AU - Barrier, M AU - Friar, E AU - Robichaux, R AU - Purugganan, M T2 - GENE AB - Several intragenically linked microsatellites have been identified in the floral regulatory genes A. sandwicense APETALA1 (ASAP1) and A. sandwicense APETALA3/TM6 (ASAP3/TM6) in 17 species of the Hawaiian and North American Madiinae (Asteraceae). Thirty-nine microsatellite loci were observed in the introns of these two genes, suggesting that they are hotspots for microsatellite formation. The sequences of four of these microsatellites were mapped onto the phylogenies of these floral regulatory genes, and the structural evolution of these repeat loci was traced. Both nucleotide substitutions and insertion/deletion mutations may be responsible for the formation of perfect microsatellites from imperfect repeat regions (and vice versa). DA - 2000/1/4/ PY - 2000/1/4/ DO - 10.1016/S0378-1119(99)00463-1 VL - 241 IS - 1 SP - 101-105 SN - 0378-1119 KW - adaptive radiation KW - floral regulatory genes KW - Hawaiian silversword alliance KW - imperfect microsatellites KW - simple sequence repeats ER - TY - JOUR TI - Host and bacterial factors involved in the innate ability of mouse macrophages to eliminate internalized unopsonized Escherichia coli AU - Hamrick, TS AU - Havell, EA AU - Horton, , JR AU - Orndorff, PE T2 - INFECTION AND IMMUNITY AB - ABSTRACT In an effort to better understand genetic and cellular factors that influence innate immunity, we examined host and bacterial factors involved in the nonopsonic phagocytosis and killing of Escherichia coli K-12 by mouse macrophages. Unelicited (resident) peritoneal macrophages from five different mouse strains, BALB/c, C57BL/6, CD-1, C3H/HeJ, and C3H/HeN, were employed. Additional macrophage populations were obtained from CD-1 mice (bone marrow-derived macrophages). Also, for BALB/c and C57BL/6 mice, peritoneal macrophages elicited with either thioglycolate or proteose peptone, bone marrow-derived macrophages, and macrophage-like cell lines derived from the two strains were employed. Two E. coli K-12 strains that differed specifically in their abilities to produce type 1 pili containing the adhesive protein FimH were examined. The parameters used to assess macrophage bacteriocidal activity were (i) the killing of internalized (gentamicin-protected) E. coli during the approximately 4-h assay and (ii) the initial rate at which internalized E. coli were eliminated. Data on these parameters allowed the following conclusions: (i) unelicited or proteose peptone-elicited peritoneal macrophages were significantly better at eliminating internalized bacteria than thioglycolate-elicited peritoneal macrophages, bone marrow-derived macrophages, or macrophage cell lines; (ii) the host genetic background had no significant effect upon the ability of unelicited peritoneal macrophages to kill E. coli (even though the mouse strains differ widely in their in vivo susceptibilities to bacterial infection); and (iii) the FimH phenotype had no significant effect upon E. coli survival once the bacterium was inside a macrophage. Additionally, there was no correlation between the bacteriocidal effectiveness of a macrophage population and the number of bacteria bound per macrophage. However, macrophage populations that were the least bacteriocidal tended to bind higher ratios of FimH + to FimH − E. coli . The effect of gamma interferon, fetal calf serum, and the recombination proficiency of E. coli were examined as factors predicted to influence intracellular bacterial killing. These had no effect upon the rate of E. coli elimination by unelicited peritoneal macrophages. DA - 2000/1// PY - 2000/1// DO - 10.1128/IAI.68.1.125-132.2000 VL - 68 IS - 1 SP - 125-132 SN - 0019-9567 ER - TY - JOUR TI - Histologic and immunohistochemical characterization of lens capsular plaques in dogs with cataracts AU - Colitz, CMH AU - Malarkey, D AU - Dykstra, MJ AU - McGahan, MC AU - Davidson, MG T2 - AMERICAN JOURNAL OF VETERINARY RESEARCH AB - To determine histologic and immunohistochemical characteristics of the multifocal adherent plaques that commonly develop on the internal surfaces of the anterior and posterior lens capsules in dogs with cataracts.31 anterior and 4 posterior capsular specimens collected during lens extraction surgery in dogs with cataracts.Specimens were evaluated, using light and transmission electron microscopy. Immunohistochemical techniques were used to localize cytokeratin, vimentin, alpha-smooth muscle-specific actin, fibronectin, tenascin, and transforming growth factor-beta (TGF-beta) within plaques.Histologically, plaques comprised elongated spindle-shaped cells that formed a placoid mass. Cells were embedded in an extracellular matrix containing collagen fibrils, often with duplicated or split basement membranes. Immunohistochemically, normal lens epithelial cells and cells within plaques stained for vimentin. Most cells and some areas of the extracellular matrix within plaques stained for TGF-beta and alpha-smooth muscle-specific actin. Fibronectin and tenascin were also detected in the extracellular matrix.Canine lens capsular plaques are histologically and immunohistochemically similar to posterior capsule opacification and subcapsular cataracts in humans, which suggests that the canine condition, like the human conditions, is associated with fibrous metaplasia of lens epithelial cells. Transforming growth factor-beta may play a role in the genesis of capsular plaques. Because severity of plaques was correlated with stage of cataract development, earlier surgical removal of cataracts may be useful to avoid complications associated with plaque formation. DA - 2000/2// PY - 2000/2// DO - 10.2460/ajvr.2000.61.139 VL - 61 IS - 2 SP - 139-143 SN - 0002-9645 ER - TY - JOUR TI - Granulomatous disease associated with Bartonella infection in 2 dogs AU - Pappalardo, BL AU - Brown, T AU - Gookin, JL AU - Morrill, CL AU - Breitschwerdt, EB T2 - JOURNAL OF VETERINARY INTERNAL MEDICINE AB - Shortly after removal of an engorged tick from the left ear, a 4-year-old Greyhound was referred for evaluation of fever and a rapidly enlarging mass in the region of the left submandibular lymph node. Histopathologic evaluation of the lymph node resulted in a diagnosis of severe granulomatous lymphadenitis. An 11-year-old mixed-breed dog was referred for evaluation of a 6-week history of serous nasal discharge. Histologic examination of a surgical biopsy from a nasal mass indicated multifocal granulomatous inflammation with fibrosis. Serum samples obtained from both dogs were reactive by immunofluorescent assay to Bartonella vinsonii subsp. berkhoffii antigens (reciprocal titers of 128). Although Bartonella organisms were not isolated by lysis centrifugation blood culture, Bartonella DNA was amplified from tissue samples obtained from each dog (lymph node biopsy from dog 1 and nasal biopsy from dog 2) using primers that amplify a portion of the 16S rRNA gene followed by Southern blot hybridization using a genus-specific probe. Additionally, restriction fragment length polymorphism (RFLP) analysis of a Bartonella-specific citrate synthase gene product obtained from dog 2 resulted in a restriction pattern identical to B. vinsonii subsp. berkhoffii. This is the 1st report of granulomatous disease in dogs associated with Bartonella infection. DA - 2000/// PY - 2000/// DO - 10.1892/0891-6640(2000)014<0037:GDAWII>2.3.CO;2 VL - 14 IS - 1 SP - 37-42 SN - 0891-6640 KW - canine KW - infectious KW - lymphadenopathy KW - pathology ER - TY - JOUR TI - Effect of long-term selection for early postnatal growth rate on survival and prenatal development of transferred mouse embryos AU - Ernst, C. A. AU - Rhees, B. K. AU - Miao, C. H. AU - Atchley, W. R. T2 - Journal of Reproduction & Fertility DA - 2000/// PY - 2000/// VL - 118 IS - 1 SP - 205-210 ER - TY - JOUR TI - Characterization of Lyme disease spirochetes isolated from ticks and vertebrates in North Carolina AU - Ryan, , JR AU - Apperson, CS AU - Orndorff, PE AU - Levine, JF T2 - JOURNAL OF WILDLIFE DISEASES AB - Borrelia burgdorferi isolates obtained from numerous locations and from different hosts in North Carolina, were compared to previously characterized strains of the Lyme disease spirochete and other Borrelia spp. The spirochete isolates were confirmed to be B. burgdorferi sensu stricto based on immunofluorescence (IFA) using a monoclonal antibody to outer surface protein A (Osp A [H5332]) and polymerase chain reaction (PCR) using a species-specific nested primer for a conserved region of the gene that encodes for flagellin. In addition, the isolates tested positive in Western blots with species-specific monoclonal antibodies for outer surface protein A and OspB (84c), and the genus-specific, monoclonal antibody to flagellin (H9724). Infectivity studies with several of these isolates were conducted using Mus musculus and Oryzomys palustris and the isolates exhibited markedly different levels of infectivity. This study demonstrates that B. burgdorferi sensu stricto is present and naturally transmitted on the Outer Banks and in the Coastal Plain and Piedmont regions of North Carolina. DA - 2000/1// PY - 2000/1// DO - 10.7589/0090-3558-36.1.48 VL - 36 IS - 1 SP - 48-55 SN - 1943-3700 KW - Borrelia burgdorferi KW - isolate characterization KW - Lyme disease KW - ticks KW - vertebrates ER - TY - JOUR TI - A mass in the spinal column of a dog AU - Neel, J AU - Dean, GA T2 - VETERINARY CLINICAL PATHOLOGY AB - Veterinary Clinical PathologyVolume 29, Issue 3 p. 87-89 A Mass in the Spinal Column of a Dog Jennifer Neel DVM, Corresponding Author Jennifer Neel DVM Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC.Corresponding author: Jennifer Neel, DVM, Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough St, Raleigh, NC 27606 (e-mail: [email protected]).Search for more papers by this authorGregg A. Dean DVM, PhD, Gregg A. Dean DVM, PhD Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC.Search for more papers by this author Jennifer Neel DVM, Corresponding Author Jennifer Neel DVM Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC.Corresponding author: Jennifer Neel, DVM, Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough St, Raleigh, NC 27606 (e-mail: [email protected]).Search for more papers by this authorGregg A. Dean DVM, PhD, Gregg A. Dean DVM, PhD Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC.Search for more papers by this author First published: 05 March 2008 https://doi.org/10.1111/j.1939-165X.2000.tb00409.xCitations: 11Read 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 onEmailFacebookTwitterLinkedInRedditWechat References 1 Clark DM, Picut CA. Neuroepithelioma in a middle-aged dog. JAVMA. 1986; 189: 1330–1331. CASPubMedWeb of Science®Google Scholar 2 Summers BA, de Lahunta A, McEntee M, Kuhajda FP. A novel intradural extramedullary spinal cord tumor in young dogs. Acta Neuropathol. 1988; 75: 402–410. 10.1007/BF00687794 CASPubMedWeb of Science®Google Scholar 3 Moissonnier P, Abbott D. Canine neuroepithelioma: case report and literature review. JAAHA. 1993; 29: 397–401. Web of Science®Google Scholar 4 Ferretti A, Scanziani E, Colombo S. Surgical treatment of a spinal cord tumor resembling nephroblastoma in a young dog. Prog Vet Neurol. 1993; 4: 84–87. Web of Science®Google Scholar 5 Terrell SF, Platt SR, Chrisman CL. Possible intraspinal metastasis of a canine spinal cord nephroblastoma. Vet Pathol. 2000; 37: 94–97. 10.1354/vp.37-1-94 CASPubMedWeb of Science®Google Scholar 6 Macri NP, Van Alstine W, Coolman RA. Canine spinal nephroblastoma. JAAHA. 1997; 33: 302–306. 10.5326/15473317-33-4-302 CASPubMedWeb of Science®Google Scholar 7 Pearson GR, Gregory SP, Charles AK. Immunohistochemical demonstration of Wilms' tumor gene product WT1 in a canine “neuroepithelioma” providing evidence for its classification as an extrarenal nephroblastoma. J Comp Pathol. 1997; 116: 321–327. 10.1016/S0021-9975(97)80006-0 CASPubMedWeb of Science®Google Scholar 8 Cotran RS, Kumar V, Robbins SL. Robbins Pathologic Basis of Disease. 5th ed. Philadelphia , Pa : WB Saunders; 1994: 464–456. Google Scholar Citing Literature Volume29, Issue3September 2000Pages 87-89 ReferencesRelatedInformation DA - 2000/// PY - 2000/// DO - 10.1111/j.1939-165X.2000.tb00409.x VL - 29 IS - 3 SP - 87-89 SN - 0275-6382 KW - cytology KW - dog KW - nephroblastoma KW - spinal cord ER - TY - JOUR TI - The case for molecular mapping in forest tree breeding AU - Rongling, W. AU - Zeng, Z.-B. AU - McKeand, AU - O'Malley, D. M. T2 - Plant Breeding Reviews DA - 2000/// PY - 2000/// VL - 19 IS - 2000 SP - 41-68 ER - TY - JOUR TI - A scaled linear mixed model for multiple outcomes AU - Lin, X. H. AU - Ryan, L. AU - Sammel, M. AU - Zhang, D. W. AU - Padungtod, C. AU - Xu, X. P. T2 - Biometrics AB - We propose a scaled linear mixed model to assess the effects of exposure and other covariates on multiple continuous outcomes. The most general form of the model allows a different exposure effect for each outcome. An important special case is a model that represents the exposure effects using a common global measure that can be characterized in terms of effect sizes. Correlations among different outcomes within the same subject are accommodated using random effects. We develop two approaches to model fitting, including the maximum likelihood method and the working parameter method. A key feature of both methods is that they can be easily implemented by repeatedly calling software for fitting standard linear mixed models, e.g., SAS PROC MIXED. Compared to the maximum likelihood method, the working parameter method is easier to implement and yields fully efficient estimators of the parameters of interest. We illustrate the proposed methods by analyzing data from a study of the effects of occupational pesticide exposure on semen quality in a cohort of Chinese men. DA - 2000/// PY - 2000/// DO - 10.1111/j.0006-341X.2000.00593.x VL - 56 IS - 2 SP - 593-601 ER - TY - JOUR TI - Rational synthesis of meso-substituted chlorin building blocks AU - Strachan, JP AU - DF O'Shea, AU - Balasubramanian, T AU - Lindsey, JS T2 - JOURNAL OF ORGANIC CHEMISTRY AB - Chlorins provide the basis for plant photosynthesis, but synthetic model systems have generally employed porphyrins as surrogates due to the unavailability of suitable chlorin building blocks. We have adapted a route pioneered by Battersby to gain access to chlorins that bear two meso substituents, a geminal dimethyl group to lock in the chlorin hydrogenation level, and no flanking meso and β substituents. The synthesis involves convergent joining of an Eastern half and a Western half. A 3,3-dimethyl-2,3-dihydrodipyrrin (Western half) was synthesized in four steps from pyrrole-2-carboxaldehyde. A bromodipyrromethane carbinol (Eastern half) was prepared by sequential acylation and bromination of a 5-substituted dipyrromethane followed by reduction. Chlorin formation is achieved by a two-flask process of acid-catalyzed condensation followed by metal-mediated oxidative cyclization. The latter reaction has heretofore been performed with copper templates. Investigation of conditions for this multistep process led to copper-free conditions (zinc acetate, AgIO3, and piperidine in toluene at 80 °C for 2 h). The zinc chlorin was obtained in yields of ∼10% and could be easily demetalated to give the corresponding free base chlorin. The synthetic process is compatible with a range of meso substituents (p-tolyl, mesityl, pentafluorophenyl, 4-[2-(trimethylsilyl)ethynyl]phenyl, 4-iodophenyl). Altogether four free base and four zinc chlorins have been prepared. The chlorins exhibit typical absorption spectra, fluorescence spectra, and fluorescence quantum yields. The ease of synthetic access, presence of appropriate substituents, and characteristic spectral features make these types of chlorins well suited for incorporation in synthetic model systems. DA - 2000/5/19/ PY - 2000/5/19/ DO - 10.1021/jo991942t VL - 65 IS - 10 SP - 3160-3172 SN - 1520-6904 ER - TY - JOUR TI - Experimental Salmonella typhi infection in the domestic pig, Sus scrofa domestica AU - Metcalf, ES AU - Almond, GW AU - Routh, PA AU - Horton, , JR AU - Dillman, RC AU - Orndorff, PE T2 - MICROBIAL PATHOGENESIS AB - The domestic pig, Sus scrofa domestica, was examined as a model for typhoid fever, a severe and systemic disease of humans caused by Salmonella typhi. Six pigs were inoculated 1 week post-weaning with approximately 10(10)colony forming units (cfu) of wild type Salmonella typhi strain ISP1820 intranasally and observed for 3 weeks. S. typhi was cultured from the tonsils of 50% of the pigs at necropsy. Cultures from all other organs analysed (ileum, colon, spleen and liver) were negative. No clinical or histopathological signs of disease were observed. Pigs inoculated in parallel with swine-virulent S. choleraesuis all exhibited signs of systemic salmonellosis indicating that the parameters of the experimental infection with S. typhi (e.g. route) were appropriate. Whereas the pig has a gastrointestinal tract that is very similar to humans, our results indicated that the unique features of host and microbe interaction needed to produce typhoid fever were not mimicked in swine. Nevertheless, our observation of tonsillar involvement was consistent with former observations of S. choleraesuis and S. typhimurium infections in swine and supports a role for the tonsil in all porcine salmonella infections. DA - 2000/8// PY - 2000/8// DO - 10.1006/mpat.2000.0367 VL - 29 IS - 2 SP - 121-126 SN - 0882-4010 KW - Salmonella KW - typhi KW - choleraesuis KW - pig KW - tonsil KW - typhoid fever ER - TY - JOUR TI - Examining rates and patterns of nucleotide substitution in plants AU - Muse, SV T2 - PLANT MOLECULAR BIOLOGY DA - 2000/1// PY - 2000/1// DO - 10.1023/A:1006319803002 VL - 42 IS - 1 SP - 25-43 SN - 1573-5028 KW - chloroplast genes KW - maximum likelihood KW - molecular clocks KW - nucleotide substitution models KW - rates of molecular evolution ER - TY - JOUR TI - Challenges of symbolic computation: My favorite open problems AU - Kaltofen, E T2 - JOURNAL OF SYMBOLIC COMPUTATION AB - The success of the symbolic mathematical computation discipline is striking. The theoretical advances have been continuous and significant: Gröbner bases, the Risch integration algorithm, integer lattice basis reduction, hypergeometric summation algorithms, etc. From the beginning in the early 1960s, it has been the tradition of our discipline to create software that makes our ideas readily available to scientists, engineers, and educators: SAC-1, Reduce, Macsyma, etc. The commercial viability of our system products is proven by Maple and Mathematica. Today’s user communities of symbolic computation systems are diverse: educators, engineers, stock market analysts, etc. The mathematics and computer science in the design and implementation of our algorithms are sophisticated. The research challenges in symbolic computation at the close of the twentieth century are formidable. I state my favorite eight open problems in symbolic computation. They range from problems in symbolic/numeric computing, symbolic algorithm synthesis, to system component construction. I have worked on seven of my problems and borrowed one from George Collins. I present background to each of my problems and a clear-cut test that evaluates whether a proposed attack has solved one of my problems. An additional ninth open problem by Rob Corless and David Jeffrey on complex function semantics is given in an appendix. DA - 2000/6// PY - 2000/6// DO - 10.1006/jsco.2000.0370 VL - 29 IS - 6 SP - 891-919 SN - 1095-855X ER - TY - JOUR TI - Body weight and tail length divergence in mice selected for rate of development AU - Rhees, BK AU - Atchley, WR T2 - JOURNAL OF EXPERIMENTAL ZOOLOGY AB - A series of mouse lines has been produced by 19 generations of restricted index selection for rate of development during early and late ontogeny. The selection program was based on an index with the following four replicated selection treatments: E(+) and E(-) were selected to alter birth to 10-day body weight gain while holding late gain for both selection lines constant; correspondingly, L(+) and L(-) were selected to alter 28- to 56-day body weight gain holding early gain for both lines constant. Herein, we characterize response to selection for growth rate by analyzing age-specific mouse body weight and tail lengths and for growth curves using a logistics model. Selection on developmental rate has resulted in divergence in both age-specific and growth curve traits. E(+) and L(+) lines reached identical weights during the late selection interval, then diverged to unique mature weights. E(-) and L(-) lines similarly achieved identical weights during late selection and diverged to unique mature weights. However, the shapes of early and late growth curves were significantly divergent, and at least two distinct growth patterns are shown to result from selection. Response in body weight gain was accompanied by similar, though less pronounced, change in tail length traits. Significant response during intervals of restricted growth was also found, especially in lines selected for late gain. The evolution of the growth trajectory under restricted index selection is discussed in terms of drift and available additive genetic variation and covariation. DA - 2000/8/15/ PY - 2000/8/15/ DO - 10.1002/1097-010X(20000815)288:2<151::AID-JEZ6>3.0.CO;2-6 VL - 288 IS - 2 SP - 151-164 SN - 0022-104X ER - TY - JOUR TI - Alan Francis Bird: 1928-99 AU - Bird, D. M. T2 - Journal of Nematology DA - 2000/// PY - 2000/// VL - 32 IS - 1 SP - 1-3 ER -