Genetics Commons^™

The Recycling Gtpase, Rab-10, Regulates Autophagy Flux In Caenorhabditis Elegans, Nicholas J. Palmisano

Dissertations, Theses, and Capstone Projects

Autophagy and endocytosis are two cellular pathways that are vital to cell growth and homeostasis. Autophagy is a dynamic and catabolic process involving the formation of a double-membrane vesicle called the autophagosome, which engulfs long-lived proteins and damaged organelles. Endocytosis involves the uptake of extracellular material into the cell through the formation of intracellular vesicles termed endosomes. Although both endocytosis and autophagy are interconnected processes, the extent to which endocytic proteins and/or compartments contribute to autophagy, and how these endocytic components do so, is still unknown. To improve our understanding of the connections that exist between autophagy and endocytosis, we …

Examination Of The Monoamine Oxidase A Gene Promoter On Motivation To Exercise And Levels Of Voluntary Physical Activity, Erin M. Kinney

Senior Theses

Purpose: The purpose of this study was to examine the genetic basis underlying voluntary exercise. Monoamine oxidase A (MAO-A) is an enzyme that acts on monoamine neurotransmitters, such as dopamine, to cause inactivation. There are several polymorphisms in the promoter region of the MAO-A gene, and these variations change transcriptional activity and the amount of MAO-A produced, leading to alterations in available dopamine levels. Interestingly, polymorphisms in MAO-A have been associated recently with physical activity level. This study sought to determine whether there is an association between motivation to exercise, levels of voluntary physical activity, and MAO-A gene polymorphisms.

Methods: …

The 'Pseudomonas Aeruginosa' Psl Polysaccharide Is A Social But Noncheatable Trait In Biofilms, Yasuhiko Irie, Aled E. Roberts, Kasper N. Kragh, Vernita D. Gordon, Jaime B. Hutchison, Rosalind J. Allen, Gavin Melaugh, Thomas Bjarnsholt, Stuart A. West, Stephen P. Diggle

Biology Faculty Publications

Extracellular polysaccharides are compounds secreted by microorganisms into the surrounding environment, and they are important for surface attachment and maintaining structural integrity within biofilms. The social nature of many extracellular polysaccharides remains unclear, and it has been suggested that they could function as either cooperative public goods or as traits that provide a competitive advantage. Here, we empirically tested the cooperative nature of the PSL polysaccharide, which is crucial for the formation of biofilms in Pseudomonas aeruginosa. We show that (i) PSL is not metabolically costly to produce; (ii) PSL provides populationlevel benefits in biofilms, for both growth and antibiotic …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

The Santa Ana Speckled Dace (Rhinichthys Osculus): Phylogeography And Molecular Evolution Of The Mitochondrial Dna Control Region, James Jay Vanmeter

Electronic Theses, Projects, and Dissertations

The purpose of this genetic study of the Santa Ana Speckled Dace Rhinichthys osculus was three-fold. The first goal was to characterize the molecular structure of the mtDNA control region of R. osculus. An 1143 base-pair region of the mitochondrial DNA genome, which included the complete control region was sequenced for all individuals. Analysis of the sequence data revealed that the molecular structure of the speckled dace control region was similar to the molecular structure described for other vertebrate taxa. The speckled dace control region contains three major domains, which vary in base frequency as well as in the frequency …

Epitaxially Grown Collagen Fibrils Reveal Diversity In Contact Guidance Behavior Among Cancer Cells, Juan Wang, Joseph W. Petefish, Andrew C. Hillier, Ian C. Schneider

Andrew C. Hillier

Invasion of cancer cells into the surrounding tissue is an important step during cancer progression and is driven by cell migration. Cell migration can be random, but often it is directed by various cues such as aligned fibers composed of extracellular matrix (ECM), a process called contact guidance. During contact guidance, aligned fibers bias migration along the long axis of the fibers. These aligned fibers of ECM are commonly composed of type I collagen, an abundant structural protein around tumors. In this paper, we epitaxially grew several different patterns of organized type I collagen on mica and compared the morphology …

Evolutionary Genetic Aspects Of Host Association In Generalist Ectoparasites, Benoit Talbot

Electronic Thesis and Dissertation Repository

Despite the use of the host for dispersal by most parasite species, the extremely loose relationship typical between highly mobile hosts and generalist ectoparasites may lead to very different gene flow patterns between the two, leading in turn to different spatial genetic structure, and potentially different demographic history. I examined how similar gene flow patterns are between Cimex adjunctus, a generalist ectoparasite of bats present throughout North America, and two of its key bat hosts. I first analyzed the continent-scale genetic structure and demographic history of C. adjunctus and compared it to that of two of its hosts, the …

Rosa Hybrid Gene Gapc Is Mutated In The Presence Of The Rose Rosette Virus, William A. Beams, Eva L. Burelos, Charles C. Hundley, Landon R. Dame, Laura G. Sims, Jacob J. Adler

Kentucky Journal of Undergraduate Scholarship

Rose Rosette Disease (RRD) harms the global rose supply by modification of the growth and development in rose cultivar. RRD spreads via a negative-sense RNA plant virus transmitted by eriophyid mites. Importantly, there is no pre-existing knowledge about the biochemistry by which this virus debilitates roses. Here we implicate glyceraldehyde-3-phosphate dehydrogenase (GAPDH), one of the major metabolic enzymes in plants, as a possible target of the virus. Genomic DNA of the cytosolic form of the protein encoded by GAPC was extracted from both virally-infected and non-infected samples of the Rosa hybrid cultivar Rosa Tropicana. The sequence results provided several distinct …

Population Genomics Of A Baboon Hybrid Zone In Zambia, Kenneth Lyu Chiou

Arts & Sciences Electronic Theses and Dissertations

Hybridization is increasingly recognized as a common, important process shaping the evolution of organisms including humans. Across hybrid zones, the genomes of incipient species are mixed and recombined through hybridization and backcrossing, creating conditions ideal for evaluating the actions of natural selection on gene variants in novel genomic contexts. This dissertation aims to increase our understanding of hybridization using a Zambian baboon study system in which two species, Kinda baboons (Papio kindae) and grayfoot baboons (Papio griseipes), hybridize despite exhibiting pronounced differences in body size and behavior. Using genome-wide genotypic data prepared using double-digest RADseq, I scan for genomic regions …

The Effects Of The Gut Microbiota On The Host Chromatin Landscape, Nicholas Semenkovich

Arts & Sciences Electronic Theses and Dissertations

The human gut microbiota is home to tens of trillions of microbes belonging to all three domains of life. The structure and expressed functions of this community have myriad effects on host physiology, metabolism, and immune function. My studies focused on a facet of host-microbial interactions and mutualism that has not been explored to a significant degree in part because of the absence of suitable tools: namely, if, when, and how the gut microbiota produces durable effects on host biology through its impact on the epigenome. To address this area, I turned to gnotobiotic mice and developed a variety of …

Genetic And Genomic Dissections Of Myelinating Glial Cell Development, Breanne Leigh Harty

Arts & Sciences Electronic Theses and Dissertations

Myelin is a multilamellar sheath made by specialized glial cells that iteratively spiral and compact their plasma membranes around axon segments. In vertebrate nervous systems, myelination facilitates rapid action propagation and provides trophic support critical for neuronal survival. In the central nervous system (CNS), oligodendrocytes (OLs) extend many processes to simultaneously ensheath multiple axons, while in the peripheral nervous system (PNS), myelinating Schwann cells (SCs) pair 1:1 with a single axon segment. Elaboration of the myelin sheath is one of the most exquisite and complex examples of massive coordinated cellular shape changes in the vertebrate nervous system. Furthermore, the importance …

Epigenetic Regulation Of Lymphocyte Development And Transformation, Yue Huang

Arts & Sciences Electronic Theses and Dissertations

Cell identity and function rely on intricately controlled programs of gene regulation, alterations of which underlie many diseases, including cancer. Epigenetic analyses of normal and diseased cells have started to elucidate different facets of epigenetic mechanisms for gene regulation. These include changes in nucleosome density, histone modifications, factor binding and chromosomal architecture. All of these aspects contribute to the activities of regulatory elements conferring promoter, enhancer and insulator functions and the cis-regulatory circuits formed by these elements. Despite this progress, an urgent need remains to profile these features and to study how they cooperatively function in normal and pathogenic settings. …

Factors That Contribute To De Novo Protein Misfolding And Prion Formation In Saccharomyces Cerevisiae, Kathryn Morgan Keefer

Arts & Sciences Electronic Theses and Dissertations

Protein misfolding is a common phenomenon that can have severe consequences on cellular and organismal health. Despite this, the causes of protein misfolding remain poorly understood. Prions are a class of proteins that, when misfolded, can convert other molecules into a heritable, non-native conformation. The yeast Saccharomyces cerevisiae naturally harbors several diverse prion-forming proteins; thus, it is an ideal model with which to investigate the factors that influence misfolding and aggregation.This thesis utilizes the yeast prions [PSI+] and [RNQ+] to investigate two distinct steps of the protein misfolding pathway: interactions with chaperones and their cofactors, and heterologous templating by other …

Epigenetic Activation Of The Mouse T Cell Receptor Beta Recombination Center, Jiangyang Zhao

Arts & Sciences Electronic Theses and Dissertations

Lymphocytes are the work horses of adaptive immunity. Compared to the B lymphocyte lineage, early stage progenitors of T lymphocytes maintain considerable potential for differentiation into other hematopoietic lineages. T lineage commitment requires the continuous coordination of transcription factors (TFs) by Notch1 signaling after multi-potent progenitors (MPPs) migrate to thymus. One of the first hall marks of T lineage commitment is expression of the T cell receptor β (TCRβ), which is encoded by the Tcrb locus following its assembly by V(D)J recombination, a somatic shuffling of the genome that joins one V, one D, and one J gene segment. Tcrb …

The Biogeographic Origins And Trophic Ecology Of Maine’S Island Red-Backed Salamanders (Plethodon Cinereus), Nikko-Ideen Shaidani

Electronic Theses and Dissertations

Island populations of terrestrial species have an increased potential, compared to mainland populations, to adapt and diverge, as these populations often are isolated with respect to gene flow from other populations and may be subjected to novel pressures. Indeed, extended isolation of individuals can elicit dramatic changes within populations and is recognized as a common driver of speciation. It is for these reasons that island populations are often a priority for conservation. Plethodontid salamanders are among the most terrestrial of Maine’s amphibians and are not tolerant of prolonged exposure to seawater, and yet, they are found on a number of …

Identification Of The Potentiating Mutations And Synergistic Epistasis That Enabled The Evolution Of Inter-Species Cooperation, Sarah Douglas, Lon Chubiz, William Harcombe, Christopher Marx

Biology Department Faculty Works

Microbes often engage in cooperation through releasing biosynthetic compounds required by other species to grow. Given that production of costly biosynthetic metabolites is generally subjected to multiple layers of negative feedback, single mutations may frequently be insufficient to generate cooperative phenotypes. Synergistic epistatic interactions between multiple coordinated changes may thus often underlie the evolution of cooperation through overproduction of metabolites. To test the importance of synergistic mutations in cooperation we used an engineered bacterial consortium of an Escherichia coli methionine auxotroph and Salmonella enterica. S. enterica relies on carbon by-products from E. coli if lactose is the only carbon source. …

Genetics Of Female Interspecific Mate Rejection In Species Of Drosophila, Ryan Calhoun

Electronic Thesis and Dissertation Repository

Speciation can occur when accumulated differences in mating behavior force diverging species to remain reproductively isolated from one another. A key determinant of behavioural isolation is the evolution of female mating preferences that prevent interspecific males from mating. However, no individual genes involved in species-specific preferences of females have yet been identified. Using various genetic mapping techniques available for studying strains and species of Drosophila, I identify candidate genes involved in D. simulans female discrimination against D. melanogaster males. One candidate gene in particular, Katanin-60, was selected for further characterization. Katanin-60 is a gene encoding a microtubule severing …

Identification Of The Potentiating Mutations And Synergistic Epistasis That Enabled The Evolution Of Inter-Species Cooperation, Sarah M. Douglas, Lon M. Chubiz, William R. Harcombe, Christopher J. Marx

Lon Chubiz

Dna Sequences Of The Mitochondrial Cytochrome C Oxidase I (Coi) Genes From Deep Sea Fishes. Cruises Dp01 And Dp02 From May 2015 - August 2015, Andrea Bernard, Max Weber, Kimberly A. Finnegan, Mahmood S. Shivji, Ron Eytan

DEEPEND Datasets

The deep sea ecosystem is believed to contain the highest biomass of fish in the oceans. However, the taxonomic diversity in this ecosystem is incompletely described and likely to be vastly underestimated. DNA sequence data (barcodes) have become a key tool to discover hidden biodiversity. We generated mitochondrial DNA barcode datasets based on the Cytochrome c oxidase I (COI) gene from deep sea fishes. These data were analyzed using phylogenetic and statistical methods to reveal cryptic species and make taxonomic linkages between adult fishes and their early life stages. These datasets were generated from fishes collected in the Northern Gulf …

Characterization Of Neuronal Specific Responses To Induced Misfolded Protein Stress In Caenorhabditis Elegans, Claire Gormley

Senior Honors Projects, 2010-2019

Abstract

Misfolded protein stress has been associated with many types of disease,

including neurodegenerative disorders like Alzheimer’s, Parkinson’s and Huntington’s

disease. When a cell accumulates misfolded proteins in the endoplasmic reticulum,

misfolded protein stress occurs and the unfolded protein response (UPR) is triggered to

induce mechanisms that will allow the cell to either survive or undergo cell death. The

nascent polypeptide associated complex (NAC) is a co-translational chaperone and α/β

heterodimer that manages protein folding and localization, and protects against misfolded

protein stress; changes in NAC function have been linked to both neurodegeneration and

cancer. In these studies, I depleted …