Genetics and Genomics Commons^™

Genomic Structure Among Populations Of A Regionally Rare Perennial Plant Indicates The Need For Reevaluation Of Management Units, Cheyenne Moore, Angela J. Mcdonnell, Scott Schuette, Christopher T. Martine

Faculty Journal Articles

Conservation of rare species often relies on the delineation of management units and genomic tools can now be applied for this purpose. However, this is not as common on a local scale, where populations are often small and fragmented, despite the utility of informing conservation and management practice at the regional level. We use a genotyping by sequencing (GBS) approach to assess the perennial riparian plant species Baptisia australis (Fabaceae) in Pennsylvania, where the taxon is at the edge of its natural distribution and considered threatened. In this system, we investigate whether sampled subpopulations exhibit genetic structure. We find that …

Rapid Identification Of Ambystoma Mexicanum Genotype Using Pcr Techniques, Elizabeth C. Dean

Undergraduate Honors Thesis Projects

Ambystoma mexicanum is an aquatic salamander species, commonly known as the axolotl, native to Mexico that is widely researched all over the world. In the wild, these salamanders have brown/black colored skin due to the presence of melanophores and xanthophores with shiny spots due to iridophores. In captivity, however, there are multiple different color morphs (phenotypes) of axolotls including leucistic, melanistic, and copper. Melanoid axolotls have black skin made by mostly melanophores, little xanthophores, and no iridophores. Melanistic genotypes such as melanoid and wild type color morphs are thought to be controlled by a single gene called Leukocyte Tyrosine Kinase …

Microbial Community And Water Quality Assessment Of Crassostrea Virginica Habitats In Southeast Florida, Stacy Brown

All HCAS Student Capstones, Theses, and Dissertations

Eastern oysters (Crassostrea virginica) are essential habitat-forming species that contribute significantly to coastal water quality due to their filter-feeding behavior. Unlike other coastal regions in the Gulf of Mexico and Northeastern United States, oysters are not commercially managed in Southeast Florida and as a result sparse data exists on locations of the Eastern oyster habitat. Similarly, the benefits of oyster reefs to water quality are also not fully documented in Southeast Florida. Although beneficial and often referred to as keystone habitat building species, populations of C. virginica are not currently listed as protected species so little work has …

Examining Loss Of Imprint In F1 Hybrid Female Mice Due To X Chromosome Epimutation And The Implications For Autism, Arianna H. Roach

Honors Scholar Theses

Sex biases are prevalent among various neurodevelopmental disorders, with males experiencing them at higher frequencies or severities than females. This male bias is poorly understood, and our lab aims to elucidate this mechanism using our model of transgenerational epigenetic inheritance. Our lab identified the cluster of genes Xlr3b/4b/4c on the X chromosome that are imprinted in the female brain. Preliminary studies suggest that Xlr3 acts as a mediator molecule in our model. Xlr3 knockdown male mice exhibited significant meiocyte loss that can be attributed to Meiotic Sex Chromosome Inactivation. Their female offspring also displayed loss of imprinting of Xlr3 and …

The Role Of Elongin B In Drosophila Melanogaster Muscle Development, Madelyne Dayan

Student Theses and Dissertations

Muscle atrophy is a result of a number of muscle diseases, as well as aging, disuse, and infections. Muscles weakened in these ways exhibit a characteristic decrease in size, strength, and mobility. The similarities between muscle in humans and Drosophila allow for direct comparisons to be made in vertebrates from studying muscle in Drosophila. Differential gene expression has been shown to play an important role in embryonic muscle development in Drosophila melanogaster. A previous study identified Elongin B (EloB) to be involved in somatic muscle morphogenesis in Drosophila, with mutant embryos displaying severe muscle defects, including thin, mis-attached, and missing …

Competence Protein Comea And Oxidative Stress In Bacillus Subtilis Stationary Phase Mutagenesis, Angeline Roldan, Sam Schauf

Undergraduate Research Symposium Posters

Stationary Phase Mutagenesis is a process where a bacterium can accumulate mutations in the absence of cell division. This may occur via competent DNA uptake and oxidant DNA damage and repair. ComEA is a transmembrane protein in B. subtilis that is required for the transport of exogenous DNA into the cell. (Figure 1)

Pseudomonas Aeruginosa Exoy Enzymatic Activity Inhibits Exos-Induced Caspase-3/7 Activation But Not Cytotoxicity In Pmvecs, Connor Holm

Poster Presentations

Pseudomonas aeruginosa (P. aer.) is the most common cause of ventilator associated pneumonia (VAP) in ICU patients. Different combinations of exoenzymes (S, T, Y, and U) are found in P. aer. strains. ExoY is most often associated with VAP in ICU patients. ExoY infection of pulmonary microvascular endothelial cells (PMVECs) induces cell rounding but does not activate intracellular caspase-3/7 or cause cell death. ExoS and ExoT infection of epithelial cells leads to caspase-3/7 dependent cell death. Previous studies using epithelial cells show that ExoY alleviates the cytotoxic effects of ExoS and ExoT. Here, we sought to determine whether ExoY inhibits …

Decoding Bacterial Resilience: Srnas And Sigma Factors In Stress Adaptation And Persistence Of Salmonella, Anita Nguyen

Poster Presentations

Small RNAs (sRNAs) are noncoding RNA molecules in bacteria that function primarily to regulate gene expression, including those associated with stress. The Borchert Lab has identified 173 sRNAs and > 500 sRNAs that are responsive to desiccation and carbon starvation (c-starvation), respectively. Prokaryotic transcription involves an RNA Polymerase (RNAP) that transcribes DNA into RNA. RNAP involves sigma factors, which recognize promoters for the initial steps of RNA synthesis. The Borchert Lab has determined that there are significant overlaps between sRNAs expressed in cells subjected to both short-term durations and long-term durations of carbon starvation. Salmonella enterica serovars can have outbreaks associated …

Rnai Pathway Homeostasis Is Essential For Longevity In C. Elegans., Sejal Dulal

2025 Spring Honors Capstone Projects - Archive

RNA interference (RNAi) is a gene regulatory mechanism that is conserved across all animal species, including humans and the microscopic nematode, Caenorhabditis elegans. Many studies have identified the RNAi pathway factors and dissected the regulatory mechanisms of RNAi pathways, but there is little understanding of how the RNAi pathways themselves are regulated. Previously, Rogers and Phillips identified a feedback loop mediated by a pair of small RNA sensors, Sensor of siRNAs-1 (sosi-1) and eri-6[e-f], embedded within the genomic locus of a small RNA biogenesis factor, ERI-6/7. In this feedback motif, loss of small RNA-mediated silencing of …

Elucidating The Role Of Transposable Element Derived Gene, Dplg3, In Drosophila Melanogaster, Kaisy A. Martinez

2025 Spring Honors Capstone Projects - Archive

A big fraction of most eukaryotic genomes is comprised of transposable elements (TEs). TEs are mobile genetic sequences often causing deleterious effects as they increase in copy number. On rare occasions, TEs can undergo molecular domestication, where the TE proteins are co-opted by the host to serve cellular functions. In Drosophila melanogaster, domestication from PIF/Harbinger TEs has resulted in five Drosophila PIF-Like Genes (DPLG1-4 and 8). This study focuses on investigating the function of DPLG3. In DPLG3 knock out lines, DPLG3-KO, a fraction of the progeny shows an abnormal gonad phenotype. We sought to confirm …

Uncovering The Evolutionary Origins Of Neo-Sex Chromosomes In The Insect Family Membracidae, Mary Kumah

2025 Spring Honors Capstone Projects - Archive

This research explores the evolution of the neo-XX/XY sex chromosome system of Amblyophallus exaltatus, a treehopper insect in the family Membracidae. Neo-XX/XY sex chromosome systems can evolve from an XX/X0 sex chromosome system via fusion events between the X chromosome and an autosome. Although cytological work has indicated the presence of a neo-XX/XY system within A.exaltatus, the chromosomal identity of the fused autosome and the molecular drivers behind this chromosomal fusion remain poorly understood. By performing a coverage analysis with whole genome sequence data, the parts of the A.exaltatus genome that fused with the X chromosome will be better …

Genetic Influence Of Allelic Variation On The Phenotypic Variability Of Cognitive Outcomes In Individuals With Williams Syndrome., Marinie P. Joseph

Electronic Theses and Dissertations

Williams syndrome (WS) is caused by a rare microdeletion of 25 – 27 genes on chromosome 7q11.23, characterized by a distinctive cognitive profile with considerable phenotypic heterogeneity. However, the genetic factors underlying this phenotypic variability remain unclear. I explored two genetic mechanisms—parent-of-origin (PoO) effects and genome-wide polygenic variation, as measured by polygenic scores (PGSs)—to elucidate possible influences on cognitive variability in WS. The first study examined PoO effects on cognitive abilities in two overlapping samples of children with WS (N = 211, N = 251). PoO refers to which parental homolog of chromosome 7 contains the WS deletion. Despite …

Integration Of Multi-Omics Datasets Evaluating Structural And Functional Features Of The Gut Microbiome In People With Hiv (Pwh)., Aakarsha Vijayakumar Rao

Electronic Theses and Dissertations

Gut dysbiosis characterized by reduced abundance of beneficial butyrate-producing bacteria has been independently linked to HIV-1 infection and heavy alcohol drinking. Further, gut dysbiosis results in loss of gut barrier integrity, microbial translocation and host-specific systemic inflammation. Therefore, to evaluate the functional consequences of structural changes in the gut microbiome, integrated data analysis is imperative. In this dissertation, we perform integrated analyses using data from multi-omics platforms to examine the structural and functional features of the gut microbiome of PWH. Gut microbiome composition was evaluated by sequencing V4 region of 16S rDNA, concentrations of metabolites and host-specific immune markers were …

A Review On Treatment, Prevention, And Research Of Worldwide Parasitic Disease: Toxoplasmosis, Hannah Skinner

All Theses

Toxoplasmosis is a worldwide, yet often overlooked, parasitic disease caused by the protozoan parasite, Toxoplasma gondii. The parasite is capable of infecting humans and almost all warm-blooded vertebrates. Over a million people are infected in the United States with toxoplasmosis each year. Most infections are asymptomatic but severe cases can lead to vision impairment, neurological disorders, and congenital birth defects. T. gondii is transmitted through undercooked meat, infected feline feces, or contaminated water and soil. The burden of T. gondii infection is most notable in livestock, felines, and immunocompromised humans. Despite being a widespread disease, toxoplasmosis is neglected in …

Life History Inhibits Deleterious Effects Of Dams On Genetic Health And Structure Of A Headwater Stream Fish, Riley Phelps

Electronic Theses and Dissertations

Habitat loss, fragmentation, and land use changes in river networks are common globally. The resulting fragmentation of landscapes and riverscapes threatens biodiversity and can affect dispersal and subsequently, gene flow and genetic health of species. Headwater streams are an integral part of river networks and contribute to biodiversity by providing habitat for temporary and permanent residents, yet they are easily altered and fragmented. The sandhills chub (Semotilus lumbee) is an endemic headwater leuciscid that lives in highly fragmented streams of the sandhills ecoregion in North and South Carolina, USA. New knowledge on the population genetics of the sandhills chub is …

Role Of Evolutionarily Conserved G4 Structures In Enhancer-Promotor Interactions, Shahem Alqudah

Honors Theses

Gene regulation is governed by complex networks of interactions between enhancers and promoters, regions of the genome that are typically distant from one another yet functionally linked through chromatin looping. Recent research has revealed the significant role of Gquadruplexes (G4s) in facilitating these interactions. This thesis explores the role of long Gquadruplex regions (LG4s) in enhancer–promoter communication, proposing that these regions mediate physical interactions between enhancers and their target promoters through direct G4:G4 interactions. Using a chromatin conformation capture (EQuIP-seq), electrophoretic mobility shift assays (EMSA), and luciferase reporter assays, the study demonstrates that LG4s may drive gene expression by promoting …

Implications Of Type Iv Pilus Retraction For Dna Uptake By Acinetobacter Baumannii, Yafan Yu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Horizontal gene transfer (HGT) via natural competence allows bacteria to incorporate extracellular DNA (eDNA) into their genomes, facilitating genetic diversity and adaptation. In Acinetobacter species, natural competence depends on DNA binding and uptake mediated by type IV pili (T4P). T4P are dynamic extracellular filaments composed primarily of the major pilin subunit PilA, along with a few minor subunits. T4P drive a range of cellular functions including twitching motility, biofilm formation, and DNA uptake, with some functions dependent on pilus retraction and others not. However, how Acinetobacter T4P bind DNA and how T4P/eDNA interactions impact biofilm formation remain unclear. Here, I …

Integrating Genomic And Phenomic Breeding Tools For Wheat Stem Sawfly Resistance In Hard Winter Wheat, Sydney E. Graham

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The wheat stem sawfly (WSS; Cephus cinctus) is an insect pest that affects wheat (Triticum aestivum) in the Northern Great Plains. This pest causes stem cutting that makes the plants susceptible to lodging and results in up to 30% yield loss. The primary management strategy for producers is utilizing host plant resistance, for which the main trait is stem solidness. This trait increases the pith thickness and provides resistance to the WSS by increasing larval mortality and reducing stem cutting. While stem solidness is largely controlled by a known major gene (SSt1), the phenotypic expression is also …

Hypoxia Induced Ribosomal Rna Fragmentation Mediated By Rnase L, Vanessa Kristina Pizutelli, Dimitri G Pestov

Rowan-Virtua Research Day

Ischemic injury contributes to a range of global pathologies. Ischemia/Reperfusion Injury (IRI) is a paradoxical phenomenon that involves an initial restriction of blood flow followed by a sudden restoration of perfusion. This type of injury takes place in conditions such as myocardial infarction, acute kidney disease, and ischemic stroke and often leads to cellular death. Additionally, IRI exacerbates post-surgical outcomes and plays a role in graft dysfunction and transplant rejection. Despite efforts to develop therapies targeting known IRI pathways, clinical trials have largely been unsuccessful, underscoring the need for alternative mechanisms and biomarkers associated with IRI-induced apoptosis. Reactive oxygen species …

Investigating The Effects Of Sod1 Knockout On Oxidative Stress And Stress Coping Styles In Zebrafish Using Crispr Technology, Tai Prauner, Ryan Wong

Theses/Capstones/Creative Projects

Reactive oxygen species are byproducts of cellular metabolism that, when not efficiently neutralized, can damage DNA, proteins, and lipids. Superoxide dismutase 1 (SOD1) is an antioxidant enzyme that converts superoxide radicals into less harmful molecules. While its molecular function is well documented, the role of SOD1 in shaping stress-related behavior remains underexplored. This project aimed to establish foundational tools for studying the behavioral impact of SOD1 knockout across proactive and reactive stress-coping styles in zebrafish.

To support future gene-editing experiments, microinjection and breeding protocols were refined across wildtype AB, proactive, and reactive zebrafish lines. No embryos were injected with CRISPR-Cas9 …

Decoding Bacterial Resilience: Srnas And Sigma Factors In Stress Adaptation And Persistence Of Salmonella, Anita Nguyen

Honors Theses

Small RNAs (sRNAs) are noncoding RNA molecules in bacteria that function primarily to regulate gene expression, including those associated with stress. The Borchert Lab has identified 173 sRNAs and > 500 sRNAs that are responsive to desiccation and carbon starvation (c-starvation), respectively. Prokaryotic transcription involves an RNA Polymerase (RNAP) that transcribes DNA into RNA. RNAP involves sigma factors, which recognize promoters for the initial steps of RNA synthesis. The Borchert Lab has determined that there are significant overlaps between sRNAs expressed in cells subjected to both short-term durations and long-term durations of carbon starvation. Salmonella enterica serovars can have outbreaks associated …

Sibship Analysis Of Fall And Spring Spawn Gulf Sturgeon Eggs In The Choctawhatchee River, Florida, Lyric Mccullouch

Honors Theses

The Gulf sturgeon (Acipenser oxyrinchus desotoi) is an anadromous species that inhabits rivers along the northern Gulf of Mexico. Facing challenges from overfishing and habitat alteration, the Gulf sturgeon is listed as threatened under the Endangered Species Act. This study investigated the genetic distinctiveness of fall and spring spawning groups of Gulf sturgeon in the Choctawhatchee River, a critical habitat for the species. In this study, I used microsatellite loci to analyze Gulf sturgeon eggs previously collected in the fall and spring of 2019 and 2020. The goals of this study were to verify the genetic identity of …

Investigating The Role Of Ilv1 On Stress Response In Saccharomyces Cerevisiae, Luke H. Beachboard

Honors Theses

Saccharomyces cerevisiae, a model organism within molecular genetics, is also known for its broad role within baking, brewing, biofuel, and pharmaceutical industries. An unpublished study at The University of Tennessee at Chattanooga observed decreased cell viability in an ILV1 Knockout strain of S. cerevisiae when exposed to environmental stressors. A subsequent study at The University of Tennessee at Chattanooga found expression levels of the candidate genes to be significantly altered within the ILV1 Knockout strain relative to the BY4743 Wildtype strain, demonstrating the reality of a pleiotropic role within ILV1. Now, this study aims to further investigate this peculiar characteristic …

Translation Of The Carcinogenic Dna Breakage-Repair Inhibition Mechanism For Hexavalent Chromium To Its Key Targets: Lung Epithelial Cells, Lung Tissue And Impacts On The Genome., Idoia Meaza Isusi

Electronic Theses and Dissertations

Lung cancer is the leading cause of cancer death worldwide. Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread occupational and environmental exposure. Despite the known health risks, how Cr(VI) causes lung cancer remains unclear. This dissertation investigates the mechanisms of Cr(VI)-induced carcinogenesis. Cr(VI) causes DNA damage, specifically DNA double strand breaks, and inhibits homologous recombination repair, a high-fidelity repair pathway. Unrepaired DNA double strand breaks or those repaired through error-prone pathways, progress to chromosomal damage, and chromosome instability. The latter is a common characteristic of Cr(VI)-exposed cells, and a hallmark of lung cancer. Although the mechanism of Cr(VI)-induced …

Gender And Race Stigma Consciousness Denialism And Reactions To Race And Gender Measures, Valerie Partida, Alicia Sylvester, Magel Baker

Celebrating Scholarship and Creativity Day (2018-)

The study examined whether denialism, defined as holding problematic stigma consciousness scores in, predicts emotional reactions to race- and gender-related survey measures. Specifically, we asked whether race stigma consciousness scores correlate with feeling upset when completing race scales, and whether gender stigma consciousness scores correlate with either positive or negative reactions to gender scales. Undergraduate students in introductory psychology courses participated (N = 38; 61 % women/gender minority, 39 % men; 21% POC, 79% White). Measures of students’ awareness of racial and gender discrimination (Pietri et al., 2018) were scored such that high scores meant that students of color (POC), …

Cloning And Heterologous Expression Of Human Nachrs And A Unique Spider Venom Toxin, Christine M. Vega

Theses and Dissertations

Drug development research has long focused on synthesizing novel therapeutics while overlooking isolation from naturally available sources. Recently, the discovery of the therapeutic effects of highly bioavailable animal venom caused the field of venom research to soar in popularity. Animal venom serves as a natural, sophisticated tool optimized over millions of years by evolution with the ability to bind to ion channels such as nAChRs, non-specific ligand-gated ion channels distributed throughout the human nervous system, with high selectivity and specificity. However, purifying individual venom toxins from crude venom is challenging due to its availability. Therefore, synthesizing large quantities of venom …

Therapeutic Applications Of A Novel Humanized Monoclonal Antibody Targeting Chemokine Receptor Ccr9 In Pancreatic Cancer, Hannah G. Mcdonald, Anna M. Reagan, Charles J. Bailey, Mei Gao, Muqiang Gao, Angelica L. Solomon, Michael J. Cavnar, Prakash Pandalai, Mautin Barry-Hundeyin, Megan Harper, Justin A. Rueckert, Ángela Turrero, Araceli Tobio, Anxo Vidal, Daniel Roca-Lema, Elia Álvarez-Coiradas, Pablo Garrido, Laureano Simón, Joseph Kim

Markey Cancer Center Faculty Publications

The relative failure of immune checkpoint inhibitors in pancreatic ductal adenocarcinoma (PDAC) despite having a dense, immunosuppressive tumor microenvironment highlights the need to target alternate/escape pathways. We have previously examined C–C chemokine receptor type 9 (CCR9) as a candidate immune checkpoint and developed a targeted, humanized monoclonal antibody (SRB2). Cytotoxicity of SRB2 was evaluated in vitro and in vivo. CCR9 expression on PDAC cells/tissues, immune components of patient-derived organoids (PDOs), and antibody-dependent cell-mediated cytotoxicity were examined. In PANC-1 and MIA PaCa-2 cell lines, we demonstrated highest CCR9 expression; however, no direct cytotoxic effect was observed with SRB2 treatment. In PANC-1 …

African Sleeping Sickness: From Basic Biology To Future Directions, Riddhi R. Patel

All Theses

African Sleeping Sickness is a Neglected Tropical Disease (NTD) which poses a significant health risk to impoverished populations in 36 Sub-Saharan African countries. It is a devastating disease caused by the protozoan parasite Trypanosoma brucei, which is transmitted to mammals via the bite of infected tsetse flies. The disease manifests in two stages: the hemolymphatic stage and the meningoencephalitic stage. In the latter stage, it invades the Central Nervous System (CNS) and can be fatal if left untreated. It is caused by morphologically indistinguishable species of Trypanosoma brucei in both humans and animals, where in humans it is known as …

Chromosome Evolution Model Reveals Hidden Variation In Karyotype-Driven Speciation In Ferns, Thomas Buchloh

All Theses

Because karyotype change commonly generates reproductive isolation between diverging species, rapid karyotype evolution, like that seen in plants, may increase the total rate of diversification. However, few studies have investigated this predicted relationship. Tests of this prediction have identified a positive correlation between the rate of karyotype change (specifically whole genome duplications) and diversification, but tests have been restricted to relatively small and young clades. Fortunately, novel macroevolutionary models have recently become available to investigate patterns of karyotype evolution in large phylogenies, providing new opportunity to investigate variation in karyotype driven diversification. Ferns are one of the most karyotype rich …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …