Genetics and Genomics | Open Access Articles

Alu Dimorphism At The Pv92 Locus Of Chromosome 16 Is In Equilibrium For University Student Population, James M. Brooks, Mackenzie L. Thackston

Journal of the South Carolina Academy of Science

Alu is a retrotransposable element, which refers to its ability to be copied and move from one region of DNA to another DNA region. At the PV92 locus of chromosome 16, Alu is a 300 bp dimorphic insert that can either be present or absent. It does not encode a protein product and has lost the ability to transpose. It is specific to humans, and differences in genotype and allele frequencies between human populations are important tools in understanding evolution. In this research, data was obtained and analyzed from 269 students at Charleston Southern University (CSU) belonging to four different …

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Cellular Localization Of Rad51d Mutant Proteins And The Application Of Art To Increase Scientific Literacy In America, Claire L. Chabot

Senior Theses

Ovarian cancers are the leading cause of death from cancer of the female reproductive system. Approximately 50% of ovarian cancers have defects in the homologous recombination (HR) DNA repair pathway that is required for the repair of DNA double-stranded breaks. The status of HR genes, such as BRCA1, BRCA2, and the RAD51 family, contributes to ovarian cancer development as well as treatment decisions regarding chemotherapy, radiation, and immunotherapy. The overarching goal of this project is to identify new insights into HR that can integrate with Precision Medicine Initiatives and align with the goals of the Cancer Moonshot 2020 Program. I …

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Threshold-Dependent Repression Of Spl Gene Expression By Mir156/Mir157 Controls Vegetative Phase Change In Arabidopsis Thaliana, Jia He, Mingli Xu, Matthew R. Willmann, Kevin Mccormick, Tieqiang Hu, Li Yang, Colby G. Starker, Daniel F. Voytas, Blake C. Meyers, R. Scott Poethig

Faculty Publications

Vegetative phase change is regulated by a decrease in the abundance of the miRNAs, miR156 and miR157, and the resulting increase in the expression of their targets, SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors. To determine how miR156/miR157 specify the quantitative and qualitative changes in leaf morphology that occur during vegetative phase change, we measured their abundance in successive leaves and characterized the phenotype of mutations in different MIR156 and MIR157 genes. miR156/miR157 decline rapidly between leaf 1&2 and leaf 3 and decrease more slowly after this point. The amount of miR156/miR157 in leaves 1&2 greatly exceeds the …

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Developmental Functions Of Mir156-Regulated Squamosa Promoter Binding Protein-Like (Spl) Genes In Arabidopsis Thaliana, Mingli Xu, Tieqiang Hu, Jianfei Zhao, Mee-Yeon Park, Keith W. Earley, Gang Wu, Li Yang, R. Scott Poethig

Faculty Publications

Correct developmental timing is essential for plant fitness and reproductive success. Two important transitions in shoot development—the juvenile-to-adult vegetative transition and the vegetative-to-reproductive transition—are mediated by a group of genes targeted by miR156, SQUAMOSA PROMOTER BINDING PROTEIN (SBP) genes. To determine the developmental functions of these genes in Arabidopsis thaliana, we characterized their expression patterns, and their gain-of-function and loss-of-function phenotypes. Our results reveal that SBP-LIKE (SPL) genes in Arabidopsis can be divided into three functionally distinct groups: 1) SPL2, SPL9, SPL10, SPL11, SPL13 and SPL15 contribute to both the juvenile-to-adult vegetative transition …

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Reactive Oxygen Species-Mediated Neurodegeneration Is Independent Of The Ryanodine Receptor In Caenorhabditis Elegans, Lyndsay E.A. Young, Daniel C. Williams

Journal of the South Carolina Academy of Science

Despite the significant impacts on human health caused by neurodegeneration, our understanding of the degeneration process is incomplete. The nematode Caenorhabditis elegans is emerging as a genetic model organism well suited for identification of conserved cellular mechanisms and molecular pathways of neurodegeneration. Studies in the worm have identified factors that contribute to neurodegeneration, including excitotoxicity and stress due to reactive oxygen species (ROS). Disruption of the gene unc-68, which encodes the ryanodine receptor, abolishes excitotoxic cell death, indicating a role for calcium (Ca²⁺) signaling in neurodegeneration. We tested the requirement for unc-68 in ROS-mediated neurodegeneration using the …

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Genome Sequence And Phenotypic Characterization Of Caulobacter Segnis, Sagar Patel

Senior Theses

Caulobacter segnis is a unique species of Caulobacter in that it is slow growing, found in soil samples, and has other phenotypic differences from the freshwater Caulobacter that it is most closely related to. Initially deemed Mycoplana segnis, it was reclassified after a 16s rRNA analysis and found to be most closely related to the Caulobacter NA1000 branch. Because the annotated sequence available in GenBank contained a large number of pseudogenes (126), we compared the original sequencing data to the GenBank sequence and determined that many of the pseudogenes were due to sequence errors in the Genbank sequence. Consequently, …

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Multiple Roles For Hoxa3 In Regulating Thymus And Parathyroid Differentiation And Morphogenesis In Mouse, Jena L. Chojnowski, Kyoko Masuda, Heidi A. Trau, Kirk Thomas, Mario Capeechi, Nancy R. Manley

Faculty Publications

Hoxa3 was the first Hox gene to be mutated by gene targeting in mice and is required for the development of multiple endoderm and neural crest cell (NCC)-derived structures in the pharyngeal region. Previous studies have shown that the Hoxa3 null mutant lacks third pharyngeal pouch derivatives, the thymus and parathyroids by E18.5, and organ-specific markers are absent or downregulated during initial organogenesis. Our current analysis of the Hoxa3 null mutant shows that organ-specific domains did undergo initial patterning, but the location and timing of key regional markers within the pouch, including Tbx1, Bmp4 and Fgf8, were altered. …

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Sugar Promotes Vegetative Phase Change In Arabidopsis Thaliana By Repressing The Expression Of Mir156a And Mir156c, Li Yang, Mingli Xu, Yeonjong Koo, Jia He, R. Scott Poethig

Faculty Publications

Nutrients shape the growth, maturation, and aging of plants and animals. In plants, the juvenile to adult transition (vegetative phase change) is initiated by a decrease in miR156. In Arabidopsis, we found that exogenous sugar decreased the abundance of miR156, whereas reduced photosynthesis increased the level of this miRNA. This effect was correlated with a change in the timing of vegetative phase change, and was primarily attributable to a change in the expression of two genes, MIR156A and MIR156C, which were found to play dominant roles in this transition. The glucose-induced repression of miR156 was dependent on the …

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Parsimony And Model-Based Analyses Of Indels In Avian Nuclear Genes Reveal Congruent And Incongruent Phylogenetic Signals, Tamaki Yuri, Rebecca T. Kimball, John Harshman, Rauri C.K. Bowie, Michael J. Braun, Jena L. Chojnowski, Kin-Lan Han, Shannon J. Hackett, Christopher J. Huddleston, William S. Moore, Sushma Reddy, Frederick H. Sheldon, David W. Steadman, Christopher C. Witt, Edward L. Braun

Faculty Publications

Insertion/deletion (indel) mutations, which are represented by gaps in multiple sequence alignments, have been used to examine phylogenetic hypotheses for some time. However, most analyses combine gap data with the nucleotide sequences in which they are embedded, probably because most phylogenetic datasets include few gap characters. Here, we report analyses of 12,030 gap characters from an alignment of avian nuclear genes using maximum parsimony (MP) and a simple maximum likelihood (ML) framework. Both trees were similar, and they exhibited almost all of the strongly supported relationships in the nucleotide tree, although neither gap tree supported many relationships that have proven …

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An Unbiased Approach To Identify Genes Involved In Development In A Turtle With Temperature-Dependent Sex Determination, Jena L. Chojnowski, Edward L. Braun

Faculty Publications

Many reptiles exhibit temperature-dependent sex determination (TSD). The initial cue in TSD is incubation temperature, unlike genotypic sex determination (GSD) where it is determined by the presence of specific alleles (or genetic loci). We used patterns of gene expression to identify candidates for genes with a role in TSD and other developmental processes without making a priori assumptions about the identity of these genes (ortholog-based approach). We identified genes with sexually dimorphic mRNA accumulation during the temperature sensitive period of development in the Red-eared slider turtle (Trachemys scripta), a turtle with TSD. Genes with differential mRNA accumulation in response to …

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Full-Text Articles in Genetics and Genomics

Alu Dimorphism At The Pv92 Locus Of Chromosome 16 Is In Equilibrium For University Student Population, James M. Brooks, Mackenzie L. Thackston

Journal of the South Carolina Academy of Science

Cellular Localization Of Rad51d Mutant Proteins And The Application Of Art To Increase Scientific Literacy In America, Claire L. Chabot

Senior Theses

Threshold-Dependent Repression Of Spl Gene Expression By Mir156/Mir157 Controls Vegetative Phase Change In Arabidopsis Thaliana, Jia He, Mingli Xu, Matthew R. Willmann, Kevin Mccormick, Tieqiang Hu, Li Yang, Colby G. Starker, Daniel F. Voytas, Blake C. Meyers, R. Scott Poethig

Faculty Publications

Developmental Functions Of Mir156-Regulated Squamosa Promoter Binding Protein-Like (Spl) Genes In Arabidopsis Thaliana, Mingli Xu, Tieqiang Hu, Jianfei Zhao, Mee-Yeon Park, Keith W. Earley, Gang Wu, Li Yang, R. Scott Poethig

Faculty Publications

Reactive Oxygen Species-Mediated Neurodegeneration Is Independent Of The Ryanodine Receptor In Caenorhabditis Elegans, Lyndsay E.A. Young, Daniel C. Williams

Journal of the South Carolina Academy of Science

Genome Sequence And Phenotypic Characterization Of Caulobacter Segnis, Sagar Patel

Senior Theses

Multiple Roles For Hoxa3 In Regulating Thymus And Parathyroid Differentiation And Morphogenesis In Mouse, Jena L. Chojnowski, Kyoko Masuda, Heidi A. Trau, Kirk Thomas, Mario Capeechi, Nancy R. Manley

Faculty Publications

Sugar Promotes Vegetative Phase Change In Arabidopsis Thaliana By Repressing The Expression Of Mir156a And Mir156c, Li Yang, Mingli Xu, Yeonjong Koo, Jia He, R. Scott Poethig

Faculty Publications

Faculty Publications

An Unbiased Approach To Identify Genes Involved In Development In A Turtle With Temperature-Dependent Sex Determination, Jena L. Chojnowski, Edward L. Braun

Faculty Publications