Ordered alphabetically by student's last
name
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Characterization of an
Unknown Gene Regulated by Marek’s Disease Virus Infection
Brittany Dixon, Amarin Cogburn, Shally Xu, and Joan Burnside Department of Animal and Food Science, University of Delaware Using cDNA microarrays, a clone, pgf1n.pk007.l8, was identified as being down regulated in chicken embryo fibroblast cells (CEF) infected with Marek’s disease virus (MDV). QPCR was used to confirm differential expression in CEF’S that were infected with MDV using laser capture microdissection (LCM) to capture plaques, adjacent cells, as well as uninfected cells. The available sequence (~500 nucleotides) had no significant matches to anything in Genbank, therefore sequence was obtained using primer walking. Analysis of differential tissue expression was investigated, using a multi-tissue Northern blot, but no conclusive data was found due to low abundance. The clone was from a fat library and analysis of ESTs in Genbank indicates this gene is expressed in the ovary, embryos, as well as the small intestine. Macrophages, both uninduced and interferon or lipopolysaccharide activated also express this gene. Homologues were sought out using a multispecies Southern blot, however, no conclusive data was found. The EST database contains sequences from rat, cow, horse, rabbit, zebrafish, ad human indicating that this gene is highly conserved in evolution. The BRIN and Science and Engineering Scholarships provided funding for this summer research project. |
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The Intracellular lifestyle
of Mycoplasma gallisepticum
The genus Mycoplasma is composed of over 100 species of small (600-1800
kb genomes), self-replicating bacteria. Mycoplasmas lack a cell wall,
require cholesterol for membrane function and growth, and are able to attach
to and sometimes pass through host cell membranes using special tip organelles.
Mycoplasma gallisepticum (MG) is an important avian pathogen causing respiratory
disease that can produce economic losses in the poultry industries. |
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Microscopic and Biochemical
Analysis of ENOD16, The symbiosis between legume plants and rhizobia bacteria results in the formation of root nodules which provide the plant with a usable form of nitrogen for growth. The rhizobia contained within each nodule convert atmospheric nitrogen into a readily utilized form for the plant. Central to this interaction is the role of the symbiosome membrane, a specialized membrane that is formed from the plant plasma membrane and surrounds each bacterium in the nodule. To better understand symbiosome membrane specialization, we have used microscopy and biochemistry to evaluate a protein, early nodulin 16, that travels through the secretory pathway and is targeted to the symbiosome membrane. Previous to this study, ENOD16 was identified in the symbiosome membrane using proteomics and further confirmed in western blot analysis. In this study, confocal light immuno-microscopy shows that ENOD16 localizes within infected nodule cells of Medicago truncatula. More specifically, a-ENOD16 label was seen around each bacteroid, and confirms previous western blot data that ENOD16 localizes to the symbiosome membrane. Western blot analysis also confirms that a-ENOD16 label is specific to ENOD16 and does not recognize other similar proteins such as ENOD20. Using these methods, we have also shown that ENOD16 localizes to infected soybean nodule cells and possibly the symbiosome membrane. The presence of ENOD16 within determinate and indeterminate nodules has been confirmed using microscopic and biochemical data. In order to determine the function of specific M. truncatula genes like ENOD16, an Agrobacterium rhizogenes-mediated Medicago transformation system has also been optimized in order to perform transformation with a transgene. This work
was supported by the University of Delaware Life Science Scholarship and
USDA NRI grants #2001-35318-10915 and #2001-35311-10161 |