Scholars Week 2016
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Browsing Scholars Week 2016 by Department "Biology"
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ItemAn Evolutionary Analysis of Membrane-Associated Guanylate Kinase Protein Family(Middle Tennessee State University, 2016) Carr, Ryan ; Deal, Heather ; Seipelt-Thiemann, Rebecca ; BiologyGene families come into being through gene and/or genome duplication followed by mutation over time which results in the evolutionarily-related genes having somewhat different nucleotides, amino acids, gene structure, and functions. The membrane-associated guanylate kinase protein family has twelve members in humans: DLG1, DLG2, DLG3, DLG4, CASK, MPP1, MPP2, MPP3, MPP4, MPP5, MPP6, and MPP7. This gene/protein family is characterized by the presence of three specific protein domains: PDZ, SH3, and GUK, all of which aid in protein-protein interactions. These proteins are known to interact with cytoskeletal proteins and also are involved in signal transduction. A characteristic member of this family is the DLG3 gene, is responsible for encoding a synapse associated protein (SAP102). The goal of this study was to better understand the evolutionary relationships among the protein/gene family members. To attain this goal, two evolutionary investigations were undertaken. First, phylogenetic trees, which are the traditional method of analysis, were constructed using the amino acids. This analysis indicated evidence for three distinct sub-groups: group A contained CASK, MPP1, MPP2, MPP6; group B contained MPP3, MPP4, MPP5, MPP7; and group C contained DLG 1, DLG2, DLG3, DLG4. Next, the phylogenetic relationship based on the exon structure was undertaken. Briefly, multiple alignments were combined exon boundary information to generate a visual map of similarities and differences in exon structure among the gene family members. This visualization and its comparison to the traditional phylogenetic analysis will be presented.
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ItemFolate Effects on Lifespan of Saccharomyces cerevisiae(Middle Tennessee State University, 2016) Hicks, Alesha ; O'Connell, Kayla O'Connell ; Seipelt-Thiemann, Rebecca ; BiologyDietary effects on lifespan have been studied for many years. The most well-known is that calorie restriction can increase longevity in many species. Previous research has also implicated restriction of certain nutrients in increasing lifespan. Reduction of folate has increased lifespan in C. elegans, both by feeding worms folate-deficient diets and biochemically inhibiting folate synthesis. Based on this research, it was hypothesized that budding yeast that are genetically deficient in the folate biosynthesis pathway would have a greater longevity than the wild type yeast. To test this hypothesis, wild type and yeast mutant in one folate biosynthesis gene, ABZ1, were aged for six consecutive weeks in rich (folate-containing) and folate-deficient media and tested for chronological lifespan using a growth assay. Final results were compared by t test to detect differences in average growth. Overall, there was no difference in growth between the wild type and mutant, rejecting our hypothesis that the ABZ1 mutant strain would have greater longevity. In addition, both yeast strains grew equally well in rich and folate-deficient media, rejecting our hypothesis that the SC medium would allow greater longevity in both yeast species. Therefore, our results did not support those from previous research in C. elegans, which indicated that reduction of folate biosynthesis has increased lifespan. As these long growth assays can be subject to contamination, it will be absolutely necessary to replicate the experiment to confirm these results.