@article{jeong_nelson_niedziela_dickey_2016, title={Effect of Plant Species, Fertilizer Acidity/Basicity, and Fertilizer Concentration on pH of Soilless Root Substrate}, volume={51}, ISSN={["2327-9834"]}, DOI={10.21273/hortsci11237-16}, abstractNote={The objective of this study was to determine how plant species, fertilizer potential acidity/basicity rating (PABR), and fertilizer concentration affect root substrate pH. Three experiments were conducted. In the first experiment, 13 herbaceous species were grown in a root substrate of three sphagnum peatmoss: one perlite (v/v) with deionized water and a neutral fertilizer (NF) with a PABR of 0 for 78 days to determine species relationships to substrate pH. The decrease in substrate pH ranged from 0.14 to 2.45 units, depending on species. In the second experiment, four of the 13 species from the previous trial representing the range of pH suppression were grown under similar growth conditions as the first experiment for 70 days. Substrate pH was lowered in the range of 0.47 to 2.72 units. In the third experiment, three fertilizers with PABRs of 150 kg·t−1 CaCO3 equivalent alkalinity, 0 neutral, and 193 kg·t−1 CaCO3 equivalent acidity were applied in a factorial design at 100 and 200 mg·L−1 N at each irrigation to kalanchoe (the species with the greatest pH suppression from the previous experiments) for 56 days. When applied at the lower fertilizer rate (100 mg·L−1 N), the PABRs resulted in the final substrate pH levels of 4.68, 5.60, and 6.11 for the acidic fertilizer (AF), NF, and basic fertilizer (BF), respectively. At the high fertilizer rate (200 mg·L−1 N), substrate pH declined continuously to 3.97, 4.03, and 4.92 for the AF, NF, and BF, respectively. Expression of PABR depended on the balance between the abiotic (chemical) effect of the fertilizers vs. the biotic (physiological) effects of the fertilizers on microbes and plants. The PABR was best expressed when the fertilizer supply was just adequate or lower indicating a closer connection to the biotic effect.}, number={12}, journal={HORTSCIENCE}, author={Jeong, Ka Yeon and Nelson, Paul V. and Niedziela, Carl E., Jr. and Dickey, David A.}, year={2016}, month={Dec}, pages={1596–1601} } @article{sommer_jackson_simpson_collins_piedrahita_petters_2012, title={Transgenic Stra8-EYFP pigs: a model for developing male germ cell technologies}, volume={21}, ISSN={["0962-8819"]}, DOI={10.1007/s11248-011-9542-6}, abstractNote={The male germ line in mammals is composed of self-renewing cells, spermatogonia, the meiotic spermatocytes and spermiogenic spermatids. Identification of these cell stages in vitro has been problematic. Transgenic animals expressing a marker gene with a promoter specific to certain cell stages in the testis would be a useful approach to identifying these cells in a viable state. Towards this end, we have produced transgenic pigs expressing mitochondrial localized enhanced yellow fluorescent protein (EYFP-mito) under control of the germ cell specific Stimulated by Retinoic Acid 8 (Stra8) promoter. Stra8 has been shown to be expressed in pre-meiotic germ cells of mice. Twelve clones harboring the Stra8-EYFP-mito transgene were produced. Analysis by Western blot indicated that expression of the transgene was limited to testicular tissue in the transgenic pigs. Single cells and seminiferous tubules were cultured in vitro and subsequently examined with epifluorescent microscopy. Expression of EYFP was noted in cells cultured for up to 5 days. Both EYFP-mito and STRA8 antibodies were shown to bind and co-localize in seminiferous tubule cells in whole mounts and in histological sections. EYFP-mito in the transgenic pigs co-localized with the endogenous stem cell marker, NANOG. Expression of the Stra8-EYFP transgene in spermatogenic cells indicates that these pigs will be useful by providing labelled cells for use in such technologies such as germ cell transplantation and in vitro spermatogenic studies.}, number={2}, journal={TRANSGENIC RESEARCH}, author={Sommer, Jeffrey R. and Jackson, Lauren R. and Simpson, Sean G. and Collins, Edwin B. and Piedrahita, Jorge A. and Petters, Robert M.}, year={2012}, month={Apr}, pages={383–392} } @article{sommer_estrada_collins_bedell_alexander_yang_hughes_mir_gilger_grob_et al._2011, title={Production of ELOVL4 transgenic pigs: a large animal model for Stargardt-like macular degeneration}, volume={95}, ISSN={0007-1161}, url={http://dx.doi.org/10.1136/bjophthalmol-2011-300417}, DOI={10.1136/bjophthalmol-2011-300417}, abstractNote={Background Truncation mutations in the elongation of very long chain fatty acids-4 (AF277094, MIM #605512) (ELOVL4) gene cause Stargardt-like macular dystrophy type 3 (STGD3). Mice expressing truncated ELOVL4 develop rapid retinal degeneration, but are poor STGD3 models since mice lack a macula. Photoreceptor topography in the pig retina is more similar to that in humans as it includes the cone rich, macula-like area centralis. The authors generated transgenic pigs expressing human disease-causing ELOVL4 mutations to better model the pathobiology of this macular disease. Methods Pronuclear DNA microinjection and somatic cell nuclear transfer were used to produce transgenic pigs for two different ELOVL4 mutations: the 5 base pair deletion (5 bpdel) and the 270 stop mutation (Y270terEYFP). Retinal transgene expression, morphology and electrophysiology were examined. Results The authors obtained four lines of Y270terEYFP and one line of 5 bpdel transgenic animals. Direct fluorescence microscopy indicated that the Y270terEYFP protein is expressed in photoreceptors and mislocalised within the cell. Immunohistochemical examination of transgenic pigs showed photoreceptor loss and disorganised inner and outer segments. Electroretinography demonstrated diminished responses in both transgenic models. Conclusions These transgenic pigs provide unique animal models for examining macular degeneration and STGD3 pathogenesis.}, number={12}, journal={British Journal of Ophthalmology}, publisher={BMJ}, author={Sommer, J. R. and Estrada, J. L. and Collins, E. B. and Bedell, M. and Alexander, C. A. and Yang, Z. and Hughes, G. and Mir, B. and Gilger, B. C. and Grob, S. and et al.}, year={2011}, month={Aug}, pages={1749–1754} } @article{sommer_collins_estrada_petters_2007, title={Synchronization and superovulation of mature cycling gilts for the collection of pronuclear stage embryos}, volume={100}, ISSN={["1873-2232"]}, DOI={10.1016/j.anireprosci.2006.10.010}, abstractNote={An efficient protocol was developed to synchronize and superovulate mature pigs for the collection of pronuclear stage embryos suitable for DNA microinjection. A timed and coordinated regimen of Lutalyse, PG600 and Chorulon along with daily checking for estrus allowed synchronization of groups of gilts having estrous cycles at regular intervals. Pigs 10-16 days after the beginning of standing estrus have been successfully synchronized into estrus using this protocol. A standard dose of each drug was used independent of size or age of the animal. One protocol averaged 38.9 ovulations and 31.1 one-cell embryos recovered per animal.}, number={3-4}, journal={ANIMAL REPRODUCTION SCIENCE}, author={Sommer, Jeffrey R. and Collins, E. Bruce and Estrada, Jose L. and Petters, Robert M.}, year={2007}, month={Aug}, pages={402–410} } @article{sommer_collins_neiding_rozeboom_wong_petters_2002, title={Conservation and regeneration of transgenic lines of swine by semen cryopreservation and artificial insemination}, volume={31}, number={1}, journal={Lab Animal}, author={Sommer, J. R. and Collins, E. B. and Neiding, T. and Rozeboom, K. and Wong, F. and Petters, R. M.}, year={2002}, pages={25–31} } @article{petters_alexander_wells_collins_sommer_blanton_rojas_hao_flowers_banin_et al._1997, title={Genetically engineered large animal model for studying cone photoreceptor survival and degeneration in retinitis pigmentosa}, volume={15}, ISSN={["1087-0156"]}, DOI={10.1038/nbt1097-965}, abstractNote={Patients with retinitis pigmentosa (RP) typically develop night blindness early in life due to loss of rod photoreceptors. The remaining cone photoreceptors are the mainstay of their vision; however, over years or decades, these cones slowly degenerate, leading to blindness. We created transgenic pigs that express a mutated rhodopsin gene (Pro347Leu). Like RP patients with the same mutation, these pigs have early and severe rod loss; initially their cones are relatively spared, but these surviving cones slowly degenerate. By age 20 months, there is only a single layer of morphologically abnormal cones and the cone electroretinogram is markedly reduced. Given the strong similarities in phenotype to that of RP patients, these transgenic pigs will provide a large animal model for study of the protracted phase of cone degeneration found in RP and for preclinical treatment trials.}, number={10}, journal={NATURE BIOTECHNOLOGY}, author={Petters, RM and Alexander, CA and Wells, KD and Collins, EB and Sommer, JR and Blanton, MR and Rojas, G and Hao, Y and Flowers, WL and Banin, E and et al.}, year={1997}, month={Oct}, pages={965–970} }