Genetics and Genomics Commons^™

Towards Understanding The Interactions Between Ospreys And Human-Made Structures In The Tennessee River Valley, Natasha Karina Murphy

Theses and Dissertations

Raptor nests on human-built structures represent a significant source of conflict as they can result in bird mortality, fires, structure damage, service distribution, or power outages when falling nest materials or animals connect with energized conductors. Power companies, such as the Tennessee Valley Authority (TVA), wish to mitigate these conflicts to avoid service disruptions. In this dissertation, I present my work towards understanding and mitigating the interactions between Ospreys (Pandion haliaetus) and human-made structures. To achieve this, I explored multiple elements of conflict identification, monitoring, and basic ecology of the target species to better inform conflict mitigation. In Chapter I, …

Examining Genetically-Informed Etiologic Models Of Co-Occurring Posttraumatic Stress Disorder And Recreational Cannabis Use Among College Students, Terrell A. Hicks

Theses and Dissertations

The college years encompass a period of increased risk recreational cannabis use (RCU), as well as a time of increased risk for trauma exposure and developing posttraumatic stress disorder (PTSD). Given the high co-occurrence between RCU and PTSD, and the potentially negative consequences of the two (e.g., worse academic outcomes), there is a need to understand the etiologic mechanisms of these commonly co-occurring conditions. Two primary phenotypic models exist: self-medication model (i.e., PTSD to RCU) and the high-risk model (i.e., RCU to PTSD). To date, there are two existing studies longitudinally examining the etiologic models proposed to explain co-occurring RCU …

Examination Of Common And Rare Variant Genetic Architecture Of Psychiatric Disorders, Mohammad Ahangari

Theses and Dissertations

Psychiatric disorders are often heterogenous in their manifestation and genome-wide association studies have identified many common risk variants involved in their polygenic architectures with varying degrees of pleiotropy. In recent years, large-scale biobanks have also begun sequencing the genome of their participants to elucidate the role of rare risk variation in the genetic architecture of complex phenotypes, including psychiatric traits. This dissertation sought to better understand the role of both common and rare risk variation in the genetic architecture of psychiatric disorders with a particular focus on schizophrenia and alcohol problems. In the first three analyses, we focused on characterizing …

Identifying Genes Downstream Of Mef2 That Influence Ethanol Sedation In Drosophila Melanogaster, Ananya Talikoti

Theses and Dissertations

Alcohol use disorder is a global public health issue that affects millions across the world. It can result in negative physical and mental health outcomes, and currently treatment options are limited and rates of relapse are high. Identifying genes that affect aspects of ethanol behaviors in model organisms, such as Drosophila melanogaster, can serve to eventually develop more robust therapeutic interventions for those experiencing alcohol dependence. Previous studies have identified a relationship between a person's initial sensitivity to alcohol and their abuse potential for the drug in later life. Therefore, we can study sedation behaviors in Drosophila melanogaster to …

Identifying Positive Selection In Multiple Subspecies Of Xylella Fastidiosa, Daniel Doroteo Flores

Theses and Dissertations

For this study, we will be looking to identify positive selection in eight genomes of the bacterial plant pathogen Xylella fastidiosa. A previous study used a branching method that identified 2 genes with positive selection along with a site-specific method identifying 34 genes showing positive selection. This current study focused specifically on the site-specific method, resulting in 28 genes (of 1,039 tested) showing positive selection. Of the 28 genes showing positive selection, 12 of them come from the pathogenicity, virulence and cellular structural categories. The remaining genes are found in the biosynthesis, metabolism, macro metabolism, and cellular process categories. …

Revisiting The Essential Informational Needs Of Parents Receiving A Diagnosis Of Down Syndrome, Margaret Jean Wilkes

Theses and Dissertations

Down syndrome is a condition characterized by varying degrees of intellectual disability (ID), distinctive facial appearance, and congenital anomalies that results from the presence of a third 21st chromosome. Down syndrome is the most common chromosomal condition, affecting approximately 12.6 per 10,000 live births in the United States, making it imperative that we determine which information is most essential to impart to parents when first presenting the diagnosis. The aim of the present study is to reassess the informational needs of parents during the presentation of a Down syndrome diagnosis. In 2009, data were collected to define the essential information …

Mef2-Bound Genes May Influence Ethanol Sedation In Drosophila Melanogaster, Katlyn M. Myers

Theses and Dissertations

Alcohol Use Disorder (AUD) is a global health issue that affects millions of people every year. This disorder has serious negative mental and physical consequences. Currently, treatment options for this disorder are largely limited to psychological therapy, with very few medications available to treat it. Being able to identify the environmental and genetic components that influence AUD can help improve diagnosis and treatment options. Previous studies in humans have shown a link between initial sensitivity and risk for alcohol abuse. Our laboratory uses Drosophila melanogaster as a model to study the genetic and environmental components of alcohol-related behaviors. Previous lab …

An Autism-Causing Variant Misregulates Selective Autophagy To Alter Axon Targeting And Behavior, Tyler Buddell

Theses and Dissertations

Neurodevelopmental disorders cause debilitating disruptions to the cellular mechanisms that underlie development of the brain. Unfortunately, the complexities of neurodevelopmental disorders make them difficult to study, and the molecular mechanisms perturbed by these disorders remain elusive. Better understanding of neurodevelopmental mechanisms, and the related genes involved, will likely yield new insight into neurodevelopmental disorders. A gene that has been associated with a number of neurodevelopmental disorders is the calcium voltage-gated channel subunit alpha1 C (CACNA1C) gene. Common and rare variants of the CACNA1C gene have been associated with autism and other neurodevelopmental disorders including schizophrenia, bipolar disorder and ADHD. However, …

Phylogenetic History Of The Amy Gene Cluster In Catarrhines, Christian M. Gagnon

Theses and Dissertations

This study phylogenetically analyzed 30 AMY-related genes from 11 primates. The results show the gradual expansion of the AMY gene family which could have allowed primates to adapt to various ecological landscapes and maximize energy intake from starch-rich foods in periods of food scarcity.

Genome-Wide Systems Genetics Of Alcohol Consumption And Dependence, Kristin Mignogna

Theses and Dissertations

Widely effective treatment for alcohol use disorder is not yet available, because the exact biological mechanisms that underlie this disorder are not completely understood. One way to gain a better understanding of these mechanisms is to examine the genetic frameworks that contribute to the risk for developing this disorder. This dissertation examines genetic association data in combination with gene expression networks in the brain to identify functional groups of genes associated with alcohol consumption and dependence.

The first study took advantage of the behavioral complexity of human samples, and experimental capabilities provided by mouse models, by co-analyzing gene expression networks …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

Does Genotype Correlate With Phenotype? Evaluating Ruffed Lemur (Varecia Spp.) Color Vision Using Subject Mediated Automatic Remote Testing Apparatus (Smarta), Raymond Vagell

Theses and Dissertations

Ruffed lemur (Varecia spp.) color vision research was conducted using a multidisciplinary approach: psychophysics, genetic analysis, technology, and animal training. The behavioral manifestation of Varecia spp. trichromacy was shown using a touchscreen apparatus (SMARTA). Trichromats performed better than dichromats when discriminating red from green (G₂ = 78.10, p < 0.001).

Pnpase In C. Elegans: Mutagenic Analysis To Complement Knockdown Studies, Danielle K. Seibert

Theses and Dissertations

PNPase is a gene implicated as a potential target for cancer therapy; human mutations also present with deafness, myopathies, and neuropathies. In this study, C. elegans was used to investigate the effect of knocking out PNPase in a whole animal. C. elegans knockdown studies have reported an extended lifespan via an increase in ROS production. Further noted are larger mitochondria and an increase in fzo-1 expression. Knockout animals previously constructed using CRISPR/Cas9 were used for this study. We aimed to confirm these findings validating previous studies. It was discovered that PNPase knockout animals demonstrated a similar lifespan extension that was …

Role Of Mitochondrial Beta-Oxidation In Ethanol Response: A Candidate Gene Study Using Caenorhabditis Elegans, Harini Pallikarana Tirumala

Theses and Dissertations

Alcohol use disorder (AUD) is the fourth leading cause of preventable death in the United States, and the fifth leading risk factor for premature death and disability, globally. There are currently very few treatment options for AUD and there is a need for effective preventive and treatment strategies for this condition. AUD risk has a significant hereditary component, with the contribution of genetic factors being estimated to be about 50%. The Davies-Bettinger laboratory uses C. elegans as a model organism to study the contribution of genetic factors in modulating neuronal responses to ethanol. In this project, we examined the role …

Investigation On Genetic Modifiers Of Age At Onset Of Major Depressive Disorder, Huseyin Gedik

Theses and Dissertations

Major Depressive Disorder (MDD) is a complex multifactorial disorder, which would lead to disability. Environmental and genetic factors are involved in MDD etiology. The aim of this project was to identify loci modifying age at onset (AAO) of MDD using survival models after adjusting for Childhood Sexual Abuse (CSA). To achieve this aim, a dataset was made available by the China Oxford and VCU Experimental Research on Genetic Epidemiology (CONVERGE) consortium. The study population had 5,220 controls and 5,282 cases with MDD. We performed two univariate association analyses using Cox Proportional Hazard (Cox PH) models. These two are Full Sample …

Genetic Counseling For Alcohol Use Disorder: Assessment Of Need In Affected And At-Risk Populations, Fayth Michelle Kalb

Theses and Dissertations

Introduction: Alcohol use disorder (AUD) is highly heritable, yet there has been no investigation regarding the possible benefits of genetic counseling for AUD. This study assessed the beliefs individuals with and at risk for AUD have regarding recurrence risk and etiology of AUD, how the presence of the condition in themselves or their family history has affected their lifestyle decisions, and potential benefit from AUD genetic counseling. Methods: An online questionnaire was distributed through social media to support groups for AUD inviting adults 18 years and older with a personal or family history of AUD. Results: Of the 122 individuals …

Reflections On The Current State Of Healthcare Transition For Young Adult Women With Turner Syndrome: Strategies For Facilitating Autonomy And Self-Management, Molly Elizabeth Snyder

Theses and Dissertations

The transition to adult-centered healthcare is a critical period for emerging adults, especially those with special healthcare needs (SHCNs). Considering the ongoing medical monitoring necessary for women with Turner syndrome (TS), it is essential that the transition process be comprehensive and well-coordinated. The aims of this study were to invite young women with TS to reflect on their healthcare transition experiences, to explore participants’ perceived control of their medical management, and to identify ways in which genetic counselors can be involved in multidisciplinary healthcare teams. The hypotheses were that young women with TS are motivated to learn more about their …

The Undiagnosed Patient And The Diagnostic Odyssey: Current Genetic Counseling Practices And Perspectives, Amelia Cordell Wardyn

Theses and Dissertations

Patients seen in genetics clinics often endure a diagnostic odyssey in their search for answers for their medical symptoms. This time is not only challenging for patients and their families, but also for the genetic counselors who are trying to help the patients. Previous research has shown that parents of children with undiagnosed medical disorders have specific goals and reasons for wanting to find a diagnosis, and there are many difficulties faced by these parents. Genetic counselors often serve as a prominent figure during the diagnostic odyssey, but little known research has assessed the current practices of and impact that …

Walking The Edge With Controversial Use Of Preimplantation Genetic Diagnosis (Pgd): Opinions And Attitudes Of Genetic Counselors, Kristen Everton

Theses and Dissertations

Purpose: This study explored opinions and attitudes of genetic counselors regarding three controversial applications of preimplantation genetic diagnosis (PGD): PGD for early-onset Alzheimer, use of embryos that are BRCA positive after PGD revealed no disease-free embryos to be available, and PGD to select against a variant of unknown significance (VUS) for Marfan syndrome. Methods: Genetic counselors were contacted through the National Society of Genetic Counselors (NSGC) electronic mailing list. Inclusion criteria required that a participant was currently practicing as a genetic counselor, was a member of the NSGC, and has counseled patients about PGD. Twenty-nine participants volunteered to participate and …

Phenotypes And Variants In Cases Submitted For X-Linked Intellectual Disability (Xlid) Gene Panel Testing, Michael J. Friez

Theses and Dissertations

Intellectual disability (ID) refers to reduced cognitive function, apparent before the age of 18, that negatively affects a person's learning and adaptive capacity. Approximately 1-3% of the population is affected with ID, males more than females, and most in the mild-to-moderate range. ID creates financial, logistical and psychosocial challenges for affected persons and their families and caregivers. It is estimated that up to 50% of ID has a genetic cause. Molecular genetic diagnosis may help in obtaining services and has important implications for family members, but can be elusive. Genes causing ID are known to be over-represented on the X …