Genetics Commons^™

Characterization Of Microrna Expression In Neuron-Enriched Extracellular Vesicles During Early Life, Allison Molen

Theses and Dissertations

Extracellular vesicles (EVs) are membrane-bound sacs released by cells that carry molecular cargo reflective of their cell of origin. EVs enriched using L1 cell adhesion molecule (L1CAM) as a marker of putative neuronal origin can cross the blood–brain barrier and provide a minimally invasive window into brain-related processes. Exosomal microRNA (miRNA) regulate gene expression and have been implicated in psychiatric disorders, including major depressive disorder (MDD). However, measuring and analyzing miRNA from L1CAM-positive EVs presents substantial analytical challenges due to low abundance and sparse detection across samples.

Plasma samples from participants recruited through the Mid-Atlantic Twin Registry (MATR) were used …

Beyond Homogeneity: Exploring Causal Heterogeneity In Psychopathology, Philip B. Vinh

Theses and Dissertations

Traditional models in psychiatric research often impose assumptions of causal homogeneity, treating population-level associations as reflective of uniform underlying mechanisms. This dissertation challenges that assumption by introducing statistical and machine learning frameworks designed to detect and model causal heterogeneity in the development of psychopathology. Central to this approach is the advancement of finite mixture structural equation modeling (FM-SEM) to identify latent subgroups characterized by distinct, and sometimes opposing, causal pathways.

The dissertation comprises three integrated empirical studies. The first introduces mixDoC, a finite mixture extension of the classical Direction of Causation (DoC) model applied to twin data, enabling the detection …

What Are The Genetic Influences Of Alcohol Sensitivity And Alcohol Metabolism? A Narrative Review Of Human Studies, Erwin Murray, Karen G. Chartier Phd, Msw

Undergraduate Research Posters

Background: Alcohol sensitivity and alcohol metabolism are two phenotypes associated with alcohol use disorder (AUD) influenced by genetics. This narrative review aims to answer “What are the genetic influences of alcohol sensitivity and alcohol metabolism?” to gain a better understanding of the genetic aspects of AUD.

Methods: A database search was performed in PubMed. Empirical human genetic studies published between 2009 and 2025 that focused on alcohol sensitivity (measured by the Self-Rating of the Effects of Alcohol scale) or alcohol-metabolizing genes were eligible for review. Studies were screened to determine inclusion for the current review.

Findings: Fifteen …

Plk1 Overexpression Drives Tumorigenesis In A Prostate Cancer Mouse Model, Emile Kachouh

Theses and Dissertations

Prostate cancer is the leading cause of cancer-related deaths among men worldwide, and the development of resistance to existing treatments necessitates the exploration of new therapeutic strategies, including combination therapies. This study investigates the role of Polo-like kinase 1 (PLK1), located on chromosome 16p12.2, as an oncogene in prostate cancer. We generated a transgenic mouse model with prostate-specific overexpression of PLK1 to closely mimic human prostate cancer progression. Quantitative PCR (qPCR) analysis was employed to characterize the molecular profile of PLK1, revealing its implication in multiple pathways. To further elucidate the functional consequences of PLK1 overexpression, we confirmed phenotypic progression …

The Splice Index As A Prognostic Biomarker Of Strength And Function In Myotonic Dystrophy Type 1, Marina Provenzano

Theses and Dissertations

Myotonic dystrophy type 1 (DM1) is a slowly progressive, multisystem disorder caused by a CTG repeat expansion in the DMPK 3’UTR that leads to global dysregulation of alternative splicing. The resulting decline in physical function is slow, and no reliable biomarkers exist for predicting disease progression; however, an RNA mis-splicing biomarker associated with weakness may have utility in predicting functional outcomes. Here we validate the Splice Index (SI) as a potential biomarker of DM1-associated strength and function. Muscle biopsies of the tibialis anterior were collected from DM1-affected individuals at baseline (n = 46) and 3-months (n = 34), along with …

The Genetic Architecture Of Cervical Change During Pregnancy: From Modeling To Mechanism — Does The Cervix Mediate Maternal Risk For Spontaneous Preterm Birth?, Hope M. Wolf

Theses and Dissertations

This project leverages clinical data and biospecimens from a prospective longitudinal cohort of pregnant women to study the genetic and phenotypic relationships between cervical shortening and the duration of pregnancy. Sonographic cervical length (CL) was measured throughout pregnancy in a cohort of 5,160 Black/African American women in Detroit, Michigan. Maternal DNA samples were sequenced with a next-generation low-pass whole genome platform. The heritability of cervical change during pregnancy and its genetic correlation with gestational age at delivery (GAD) were estimated using Genome-Wide Complex Trait Analysis. These estimates suggest that cervical change is heritable (h²CL = 51%) and highly polygenic trait. …

Re-Programming Transcription Factor Function For Neuroscience Research Of Addiction: Investigating The Role Of Zinc Finger Proteins In Driving Cocaine Reinforcement In Mice, Joseph A. Picone

Theses and Dissertations

Administration of addictive drugs like cocaine or morphine initiates aberrant gene transcription within brain reward circuitry neurons, which contributes to the lasting behavioral maladaptations that define addiction. The drug-induced expression and function of key brain transcription factors (TFs) is one major mechanism through which these drugs are able to regulate transcription, and as a consequence, lasting damaging drug-related behaviors including compulsive drug use. The goal of this dissertation is to more fully understand the molecular mechanistic drug-specific actions of TFs within the rodent nucleus accumbens (NAc). The findings from these studies could serve as the basis to identify novel candidate …

A Comparison Of Three Dna Extraction Methods On 45-Year-Old Pupae Cases, Ananya Udyaver, Casey Flint, Jeffery Tomberlin, Baneshwar Singh

Undergraduate Research Posters

Blow flies are the primary colonizers of human cadavers. In many death investigations, insect evidence can help in prediction of minimum post-mortem interval (PMImin) but to do that, the first step is to identify collected insect evidence. For immature stages, morphological keys are either limited or incomplete and hence DNA based identification is used. For DNA based ID, DNA extraction is the first and the most important step, especially when collected evidence is highly degraded. The main aim of this study was to compare three DNA extraction methods (QIAgen Blood and Tissue Kit, organic, and QIAgen DNA Investigator Kit) to …

Association Of Interpersonal Trauma And Polygenic Risk Scores With Depressive Symptoms In College Students, Rowan K. O'Hara

Theses and Dissertations

Major depression is considered a complex trait influenced by both polygenic risk factors and environmental exposures, such as childhood trauma. This study applied statistical genetic methods to calculate aggregate genetic risk for major depression to predict depressive symptoms scores in a college student sample. Data were from the Spit for Science (S4S) study in which college students from a large urban university self-reported interpersonal trauma (IPT) exposure prior to college and depressive symptoms from the past month (N = 7502; ancestry group: 20% African [AFR], 12% Admixed Americas [AMR], 10% East Asian [EAS], 49% European [EUR], 8% South Asian [SAS]). …

Integrative Post-Gwas Analyses Of Psychiatric Disorders: Identifying Putative Risk Genes And Gene Sets Using Transcriptome, Proteome And Methylome Information, Huseyin Gedik

Theses and Dissertations

Genome-wide association studies (GWAS) of psychiatric disorders (PD) yield numerous loci with significant signals, but often they do not implicate specific protein coding genes. Because GWAS risk loci are enriched in expression/protein/methylation quantitative loci (e/p/mQTL, hereafter xQTL), transcriptome/proteome/methylome-wide association studies (T/P/MWAS, hereafter XWAS), which integrate information from GWAS and x-level (mRNA, protein or DNA methylation levels) coming from largest xQTL studies, can link GWAS signals to effects on specific genes. For gene level analyses, researchers use mendelian randomization (MR) methods to fine-map the association between x-levels and trait. However, none of the previous studies ever jointly analyzed XWAS of multiple …

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 …

Gene Drives And The Consequences Of Over-Suppression, Cole Butler

Biology and Medicine Through Mathematics Conference

No abstract provided.

Evaluating Population Genetic Structure And Potential Genomic Signals Of Natural Selection In A Migratory Songbird (Protonotaria Citrea), Tyler A. Hohenstein

Theses and Dissertations

In this study I attempted to further resolve the population genetic structure in the Prothonotary Warbler (Protonotaria citrea), and conducted an outlier SNP analysis and exploratory gene ontology analysis to investigate potential ongoing natural selection in the species. This analysis of population structure confirms previous work by DeSaix et al. (2019), where weak population structure was observed between eastern sites along the Atlantic Coastal Plain, and western sites in the Mississippi Alluvial Valley, possibly due to a genetic discontinuity across the Appalachian Mountains. I conducted two forms of outlier SNP analyses, a principal component analysis (PCA)-based approach to identify SNPs …

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 …

Attitudes And Opinions About Direct-To-Consumer Genetic Testing In Undergraduate Science Students, Morgan N. Driver, Sally I-Chun Kuo, Olivia Nayeri, Chloe J. Walker, Chelsea Derlan Willians, Tricia Smith, Amy E. Adkins, Danielle M. Dick

Graduate Research Posters

Background: There has been exponential growth in the number of direct-to-consumer genetic testing kits sold in the past decade. Consumers utilize direct-to-consumer genetic tests for a number of reasons which include learning about one’s ancestry and potential ways to manage health. Emerging adults tend to be early adopters of new technologies; however, there has been little research regarding the opinions about direct-to-consumer genetic testing in emerging adults.

Methods: Data came from a study conducted in an upper-level biology course focusing on understanding undergraduate science students’ overall experiences with receiving personalized genetic testing results from 23andMe. The present study used data …

Identification And Optimization Of Mirna Biomarkers For Body Mass Index (Bmi) Estimation In Forensic Samples, Jennifer J. Shealy

Master of Science in Forensic Science Directed Research Projects

DNA profiles do not provide as much evidentiary value when either all known samples can be excluded or when there is no known suspect. DNA phenotyping is a technique used for investigative purposes to predict externally visible characteristics (EVCs) based on specific markers found in the genome. Most phenotyping panels are currently restricted to markers stable over a lifetime within an individual and are not able to predict environmental or metabolic impacts on EVCs. It is known that miRNA expression levels change due to environmental and metabolic factors, such as BMI, and research has proven associations between circulating plasma miRNAs …

The Role Of Manganese In Streptococcus Sanguinis, Tanya M. Puccio

Theses and Dissertations

Streptococcus sanguinis is primarily associated with oral health as a commensal bacterium. As an opportunistic pathogen, S. sanguinis is capable of colonizing heart valve vegetations, leading to the disease infective endocarditis. Previous studies from our lab have identified the high-affinity manganese transporter SsaACB as important for endocarditis virulence. The impact that manganese depletion has on S. sanguinis had never been evaluated and a secondary manganese transporter has not been identified. Thus, we employed the use of a fermentor to control large-scale growth over time and depleted manganese in an ΔssaACB mutant using a metal chelator, EDTA. The changes in …

The Origin And Evolution Of Flower Characters In Angiosperms With A Case Study On The Genetic Basis Of Zygomorphic Corolla Development In Bee And Hummingbird Pollinated Species Of Schizanthus (Solanaceae), Ghadeer Bukhari

Theses and Dissertations

This Ph.D. dissertation investigates two main projects separated into two chapters, one for each. The first chapter explores the evolution of flowering plants (angiosperms), a macro-scale study. The second project is on a micro-scale that focus on exploring the genes that regulate the similarities and the differences of flower morphology reflecting their different pollination syndromes in two species of Schizanthus (Solanaceae), i.e., S. pinnatus, a bee-pollinated flower, and S. grahamii, a hummingbird- pollinated flower.

In the first chapter, I used floral diagrams to study the origin and the evolution of floral traits in angiosperms, a new set of morphological data …

Novel Strategies To Overcome Carboplatin Resistance In Triple Negative Breast Cancer Using Patient Derived Xenografts, Mohammad A. Al Zubi

Theses and Dissertations

Triple-negative breast cancer (TNBC) patients have a poor prognosis and rely on chemotherapeutic treatment as standard of care. Often, they develop chemotherapy resistance, which leaves them without more therapeutic options, like targeted therapy. New models have been developed to test targeted inhibitors in human tumors, and they are known as patient-derived xenografts (PDX). These tumors are obtained from patients, then established and maintained in mice where they areused for tumor studies. In this work, we characterized 14 PDXs for their primary tumor growth rate and investigated metastatic propensity using spontaneous and experiment metastasis models. We utilized RNA-sequencing to characterize contributions …

The Gamma-Globin Repressors Klf1, Bcl11a, And Mbd2: Knowledge Gaps In The Literature, Lauren Nufer

Theses and Dissertations

β-hemoglobinopathies affect millions of people around the world. Research into treatments for these conditions has focused on methods to increase γ-globin expression, because increased levels of γ-globin ameliorate or reduce the severity of symptoms. As more and more studies have been done, a few proteins have emerged as having crucial roles in γ-globin repression and have been established as key genes to study. These are Krüppel-like factor 1 (KLF1), B cell CLL/lymphoma 11A (BCL11A), and methyl binding domain 2 (MBD2). The roles of these proteins in the switch from fetal to adult hemoglobin and in repressing γ-globin expression have been …

Glial Cell Mechanisms Regulate Alcohol Sedation In Drosophila Melanogaster, Kristen M. Lee

Theses and Dissertations

Approximately 16 million people in America are diagnosed with Alcohol Use Disorder (AUD) but no efficacious medical treatments exist. Alcohol-related behaviors can be studied in model organisms, and changes in these behaviors can be correlated with either (i) a risk for alcohol dependence or (ii) a symptom/feature of AUD itself. Although AUD is a disease of the central nervous system, a majority of research has focused on the neuronal underpinnings, leaving glial contributions largely undescribed. We used Drosophila melanogaster (fruit fly) to identify genes whose expression in glia regulates alcohol sedation. Mammals and Drosophila have conserved behavioral responses to alcohol …

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 …

The Increased Frequency Of Micronuclei Seen In Women With A History Of Childhood Sexual Abuse Reflects More Numerical Than Structural Acquired Chromosomal Events: A Discordant Identical Co-Twin Study, Kaitlyn M. Dochelli

Theses and Dissertations

Childhood sexual abuse (CSA) is a stressful life experience with lasting/far-reaching health and psychopathological consequences. Our laboratory recently identified a significantly increased frequency of acquired chromosomal anomalies (assessed using the cytokinesis-blocked micronucleus assay) in adult female twins exposed to CSA when compared to their unexposed co-twin. The primary aim of this study was to evaluate potential mechanism(s) underlying the observed increases in levels of micronuclei in an expanded group of 90 female identical twins (61 CSA+ females and 29 CSA- females [including a total of 27 MZ co-twin pairs]) using fluorescence in situ hybridization (FISH) methodologies, with PNA probes specific …

Phenotypic Characterization Of Pnpase Mutation And Overexpression In C. Elegans, Brian J. Hur

Theses and Dissertations

PNPase, polynucleotide phosphorylase, is a multifunctional exoribonuclease protein with 3` terminal oligonucleotide polymerase activity. Coded by the PNPT1 gene, the protein is associated with mitochondrial homeostasis and functions as a possible target for cancer therapy. In this study, C. elegans was used to investigate the effect of mutation and overexpression of pnpt-1, the gene that encodes PNPase. It was determined that two specific mutations in pnpt-1 did not affect PNPase expression nor did they produce deleterious phenotypes that affected polycistronic transcript accumulation or ROS production. Creation of a stable overexpression model was achieved through Fusion PCR. However, different transgenic …

Testing For Cryptic Diversity And Inference Of Population Structure In The Cosmopolitan Hoplonemertean Emplectonema Gracile (Nemertea), Paul L. Delaney Iv

Theses and Dissertations

Emplectonema gracile (Johnston 1837) is a hoplonemertean of marine intertidal hard-bottom communities and is distributed throughout the Northern Hemisphere. Although possessing a planktonic larval stage in its life history, the range of such cosmopolitan marine invertebrate species is often explained by cryptic speciation and anthropogenic transport. The purpose of this study is to test for possible cryptic species using mtDNA markers (COI and 16S rDNA) and to investigate population structure in E. gracile over a portion of its geographic range using mtDNA markers and ddRADseq nuclear SNP data. The results of both phylogenetic- and tree-based species delimitation revealed that E. …

Co-Localization Of Polycystic Ovary Syndrome Candidate Gene Products In Human Theca Cells Suggests Novel Signaling Pathways, Rewa M. Kulkarni

Theses and Dissertations

Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility and the most common endocrinopathy of women of reproductive age. Genome-wide association studies (GWAS) identified a number of loci associated PCOS in different ethnic populations, including women with Asian and European ancestry. Replication studies have confirmed some of these associations. Among the loci identified are those located near the LH receptor gene (LHCGR), a clathrin-binding protein gene (DENND1A) that also functions as a guanine nucleotide exchange factor, and the gene encoding RAB5B, a GTPase and protein involved in vesicular trafficking. The functional significance of one …

Genetic And Environmental Factors Influence Drosophila Ethanol Sedation, Rebecca E. Schmitt

Theses and Dissertations

Alcohol use disorder is a global health issue that affects a significant portion of the population, with affects including both negative mental and physical consequences. Currently, there are few treatment options available to those who suffer from alcohol use disorder, alcohol abuse, or alcohol dependence. Identifying candidate genes or environmental influences would therefore improve the means for possible treatments or identification of those people at risk for alcohol use disorder. Previous studies in humans have demonstrated an inverse association between initial sensitivity and risk for alcohol abuse. This connection allows investigators, and our laboratory, to investigate genetic and environmental factors …

Spatial Genetic Structure And Local Adaptation Within And Among Foxtail Pine (Pinus Balfouriana Subsp. Balfouriana) Populations Located In The Klamath Mountains, California, Rebecca D. Piri

Theses and Dissertations

Foxtail pine (Pinus balfouriana) is a subalpine conifer endemic to California, notably separated into two disjunct subspecies. Previous studies have described the northern subspecies,Pinus balfouriana subsp. balfouriana,as having an uncommonly high level of genetic differentiation and no discernible spatial patterns in phenotypic variation. This study seeks to characterize the spatial genetic structure and patterns of selection of the northern subspecies (Pinus balfouriana subsp. balfouriana) using genome-wide data and to identify the influence of ecology and environment on the unique genetic patterns. I show that genetic differentiation among populations is much less than previously estimated …

Snd1-Targeted Gene Therapy For Hepatocellular Carcinoma, Bryan D. Mckiver

Theses and Dissertations

Staphylococcal nuclease and tudor-domain containing 1 (SND1) is an oncogene for a wide variety of cancers, including hepatocellular carcinoma (HCC). SND1 is a multifunctional protein regulating gene expression of proto-oncogenes and tumor suppressor genes, making SND1 a prime target for developing cancer therapeutics. This notion is especially attributed to HCC as most patients are diagnosed in advanced stages and the therapeutic options available for these patients are severely limited. In this study, we evaluated the therapeutic potential of a replication-defective adenovirus vector delivering SND1 shRNA (Ad.SND1sh) to human HCC cell lines, HepG3, HuH-7, and Hep3B. Adenovirus infection in HCC cells …

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 …