Life Sciences Commons^™

Distribution, Abundance, And Population Genetics Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Mississippi, Luke Pearson

Dissertations

The southeastern United States is a freshwater turtle biodiversity hotspot, second only to southeastern Asia, and this region is inhabited by one of the largest freshwater turtles in the world: the alligator snapping turtle (Macrochelys temminckii). This species was heavily harvested from the 1960’s to the 1980’s for the turtle soup industry, apparently contributing to substantial, range-wide population declines. These declines, coupled with anthropogenic impacts on riverine and floodplain habitats, have led to M. temminckii being petitioned for federal listing under the U.S. Endangered Species Act; it is currently under review by the U.S. Fish and Wildlife Service …

Divergent Selection For Water Conversion Ratio In Broiler Populations, Joseph Hiltz

Graduate Theses and Dissertations

Water scarcity is a global reality and with the anticipated population growth, freshwater resources will be further strained to meet both human needs and agriculture applications. To ensure a water sustainable and food secure future, all aspects of agriculture must become more efficient. Two strategies were explored. The potential of improving water efficiency in broilers was examined. The first strategy was to develop a more efficient and accurate method for measuring water consumption/inputs in agriculture. To date, water measuring technology has lacked the necessary sophistication to assure accuracy and repeatability of low flow water usage.

After establishing a low flow …

Mutant Kras Alters Extracellular Vesicle Microrna Sorting In Pancreatic Cystic Neoplasms, Rachel L. Dittmar

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest cancers by organ site with a 5-year survival rate of just 10.8%. This is largely because most patients do not experience symptoms until the disease has already metastasized. The best hope to cure PDAC is surgery, which can only be done with a curative intent at an early stage when the disease is localized. There are no reliable circulating, body-fluid-based biomarkers to detect early stage PDAC or its precursor lesions in a timely manner for effective surgical intervention. When potential PDAC precursor lesions, such as mucinous pancreatic cysts are found, there are …

Population Genetic Analyses Of Arctic Char (Salvelinus Alpinus) Life History Types In Nettilling Lake & Amadjuak River Ecosystem: A Test Of Reproductive Isolation, Chen Liu

Electronic Theses and Dissertations

A great number of studies have identified strong genetic differences between sympatric anadromous and resident populations of Salmonidae. However, Arctic char (Salvelinus alpinus) migratory phenotypes in the Nettilling Lake and Amadjuak River ecosystem in Nunavut, Canada have not been genetically characterized, and it remains unclear if distinct genotypes and phenotypes associated with migratory life history differences are maintained through reproductive isolation, and they have been assumed to be sympatric populations, or co-occurring populations. Co-occurring Arctic char (n=225) were sampled from eleven sites along the Amadjuak River in 2014 and 2015. Twelve microsatellite loci were used to quantify genetic variation among …

Phylogenomics And Population History Of Cichlid And Live-Bearing Fish Species In Lowland Neotropical Rivers, Konrad Taube

College of Science and Health Theses and Dissertations

Within Middle America, cichlids and poeciliids account for more than half of the fish biodiversity. This richness in fish fauna highlights the complexity of Middle American biogeography: no other continental area on earth contains within its range the unparalleled abundance of secondary freshwater fish species (fish that can tolerate both saltwater and freshwater). Research into the biogeography of widely distributed Middle American freshwater fish is essential to understanding this unique region.

Three species of freshwater fishes (Belonesox belizanus – Pike killifish, Vieja maculicauda – Black belt cichlid, and Gambusia nicaraguensis – Nicaraguan mosquitofish) are widely distributed across rivers on …

Genetic Approaches For The Study Of Complex Human Diseases, Julieta Lazarte

Electronic Thesis and Dissertation Repository

The field of human genetics has evolved from its initial narrow focus on single-gene Mendelian disorders, which largely affect children, to our current understanding that for most diseases there is continuum of rare to common variants which can exert a range of phenotypic effects. Despite advances in sequencing capabilities and our overall understanding of diseases, there remains a large proportion of heritability unexplained. Through the use of next-generation sequencing technologies and DNA microarray, I have explored a spectrum of genetic variations from rare, single and structural variants to common variants in individuals with i) “lone” atrial fibrillation; ii) familial hypercholesterolemia; …

Genetic Resistance To The Downy Mildew Pathogen And Breeding Towards Durable Disease Management In Spinach, Bazgha Zia

Graduate Theses and Dissertations

Spinach (Spinacia oleracea) is a self-pollinated, dioecious winter crop. Prevalent challenges to the production of spinach include disease pressure imposed by downy mildew, which is caused by Peronospora effusa (=P. farinosa f. sp. spinaciae [Pfs]). A total of 19 new races of P. effusa have emerged, imposing serious challenges to the disease management in spinach production. Accordingly, this study was designed to explore the genetic components for establishing the basis of durable disease resistance development against the downy mildew pathogen (P. effusa 13) in spinach, through the use of various genome engineering approaches.

Our results have led (Chapter 2) to …

The Role Of Single Nucleotide Polymorphisms Causing A Dysregulation Of The Hpa Axis On The Incidence Of Depression, Elsa Bechu, Brian Cohen

Honors Theses

Depression is one of the most prevalent diseases worldwide, afflicting approximately 17 million adults in the US in 2019. A prominent causal factor of depression is dysregulation of our body’s response to stress when exposed to continuous stressors over long periods of time. Stress is regulated by the Hypothalamic-Pituitary-Adrenal (HPA) axis, with cortisol as its effector hormone. The effects of cortisol are exerted through the glucocorticoid and mineralocorticoid receptors (GR and MR, respectively) in the body and the brain, respectively. The HPA axis is regulated by a negative feedback loop where activation of the GR by circulating cortisol inhibits the …

The Role Of Subclonal Gene Mutations During Progression From Myelodysplastic Syndrome To Secondary Acute Myeloid Leukemia, Andrew John Menssen

Arts & Sciences Electronic Theses and Dissertations

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal bone marrow disorders characterized by ineffective hematopoiesis. Approximately 30% of MDS patients progress to secondary acute myeloid leukemia (AML). MDS is caused by somatic mutations in hematopoietic stem/progenitor cells and progression to secondary AML is associated with the acquisition and/or expansion of at least one subclone. We hypothesized that specific gene mutations would be enriched in subclones compared to founding clones, and that the order of mutation acquisition would be critical for clonal evolution and progression from MDS to secondary AML. Sequencing of paired MDS and secondary AML samples from 44 …

Molecular And Genetic Studies Of Robo2 Transcriptional Regulation In The Central Nervous System Of Drosophila Melanogaster, Muna Abdal Rahim Abdal Rhida

Graduate Theses and Dissertations

Drosophila Robo2 axon guidance receptor is a member of the evolutionarily conserved Roundabout (Robo) protein family that is involved in directing axons that cross the midline to the other side of the animal body. Robo2 roles mainly depend on two factors: The functional domains of the Robo2 protein, which is extensively studied, and the dynamic transcription of robo2 in various subsets of cells throughout embryogenesis which is not fully understood. Thus, knowing robo2 enhancers that transcriptionally regulate robo2 during embryogenesis is significant. To investigate robo2 potential enhancers, we screened 17 transgenic lines of Drosophila that were generated by Janelia Research …

Evaluating Insurance Approval Rates Of Exome Sequencing And Its Effect On Minority Patients' Access To Genetic Care, Katlyn Frane

Dissertations & Theses (Open Access)

Exome sequencing (ES) is often a standard step in the genetic testing process for patients with rare or complex disease. Despite clinical implementation of ES, insurance companies (payers) continue to deny this test. We investigated if the payer barrier is influenced by payer type, and if other demographic or clinical information correlated to ES approval and obtainment. To do this, a retrospective chart and clinical database review was completed on patients seen at a tertiary care center and community-based clinic. Patient demographics, clinical indications, and testing recommendations and outcomes were used to assess ES approval and obtainment. We found that …

Using Crispr-Cas9 To Characterize The Role Of Gli-Similar 3 (Glis3) In Insulin Regulation, Pancreatic Development, And Type 2 Diabetes, Lilyanne Grieve

Honors College Theses

The prevalence of type 2 diabetes continues to rise nationally and internationally, impacting millions of people worldwide. Type 2 diabetes results from insulin resistance leading to chronic hyperinsulinemia and dysfunction of the insulin producing β cells of the pancreas. While environmental factors can influence the development of type 2 diabetes, research has shown genetics are also involved. Gli-similar 3 (Glis3), a Krüppel-like zinc finger transcription factor, has been identified as a novel regulator of insulin transcription. Evidence has shown that loss-of-function Glis3 mutations decrease insulin expression, implicating Glis3 in the development of type 2 diabetes. However, the distinct role Glis3 …

Genetics Of Pediatric Musculoskeletal Disorders, Lilian Antunes

Arts & Sciences Electronic Theses and Dissertations

Pediatric musculoskeletal disorders are an extremely broad category of diseases that are often inherited. While individually rare, collectively these disorders are common, affecting around 3% of live births in the US. Despite the mounting clinical and molecular evidence for a genetic etiology, the cause for many patients with pediatric musculoskeletal disorders remain largely unknown. Major challenges in rare pediatric diseases include recruiting large numbers of patients and determining the significance and functional impacts of variants associated with disease within individuals or families. Whole exome sequencing (WES) is a powerful tool to identify coding variants that are associated with rare pediatric …

A Multispecies Perspective Into Dietary Genetic Adaptations And Ancient Migration In The Peruvian Andes, Kelsey Jorgensen

Wayne State University Dissertations

Successful adaptation to the high-elevation Andes would have required both cultural and biological adaptations by early human populations. These past adaptations continue to shape the evolutionary outcomes of both humans and non-human species today. A multispecies perspective was used to examine how humans and non-human creatures, specifically insects, were shaped by past human adaptations. This dissertation asked two primary questions: 1) Given the importance and evolutionary history of potato consumption in the Peruvian Andes, is a genetic adaptation to better digest potato starch detectable in present-day Peruvians? and 2) Using the Andean Potato Weevil (APW) phylogeny as a proxy, what …

Population-Matched Transcriptome Prediction Increases Discovery And Replication Rate In Twas, Elyse Geoffroy

Master's Theses

Most genome-wide and transcriptome-wide association studies (GWAS, TWAS) focus on European populations; however, these results cannot always be accurately applied to non-European populations due to differences in genetic architecture. Using summary statistics from GWAS in the Population Architecture using Genomics and Epidemiology (PAGE) study, which comprises ~50,000 Hispanic/Latinos, African Americans, Asians, Native Hawaiians, and Native Americans, we perform transcriptome-wide association studies to determine gene-trait associations. Initially, we compared results using two transcriptome prediction models derived from the Multi-Ethnic Study of Atherosclerosis (MESA) populations: the African American (AFA) model and the Hispanic/Latino (HIS) model. We identified 141 unique genome-wide significant trait-associated …

Will There Be Changes In Sexually Differentiated Behaviors In Mice Manipulated For The Sry Gene As They Mature Into Adultood?, Subin Joo

CMC Senior Theses

Sexually differentiated behavior has been shown to be affected by both genes and hormones. The discovery of the SRY gene, which codes for the development of testes, lead to the development of the Four Core Genotypes model of mice, and the separation of sex chromosomes and its resulting gonadal hormones. Using the FCG model, this study aims to look at the development of sexually differentiated behavior in mice, and track how it changes throughout their life. FCG mice will be divided into individual and social housing, and repeated experiments carried out to test their reaction to both intact female and …

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 …

Examining Human Apoe Genotype And Sex As Modulators Of Respiratory Plasticity In The Presence And Absence Of Spinal Cord Injury, Lydia Ella Strattan

Theses and Dissertations--Neuroscience

There are over 17,000 new spinal cord injuries (SCIs) every year in the Unites States alone. Almost 60% of these injuries occur at the cervical level, potentially leading to loss of function in a variety of sensory and motor systems including upper and lower limbs, respiratory, and autonomics. In addition to the physical and emotional costs, individuals who experience these higher level injuries also face a massive financial burden, incurring over $1 million in expenses during the first year after injury in addition to substantial yearly costs for the rest of their lifetime. A myriad of therapeutic approaches targeting plasticity …

Examining A Functional Interaction Between Chromatin Remodeler Chd1 And Histone H1 In D. Melanogaster, Breanna Kim

Scripps Senior Theses

Chromodomain-helicase-DNA-binding-protein-1 (CHD1) is a highly conserved ATP- dependent remodeling protein. It is localized to active genes and directs nucleosome spacing, while its loss has been linked to various human diseases, such as human prostate cancer. In Drosophila, CHD1 is important for fertility and wing development, and overexpression of CHD1 leads to severe wing vein defect phenotypes. The Linker Histone H1, which is known for maintaining heterochromatin and is associated with inactive genes, had been previously identified as a possible functional partner of CHD1, though the exact nature of their interaction is unclear. I undertook a genetic approach to examining the …

Composition And Homology In The Taxonomic Classification Of Escherichia Coli, Tanya Irani

Theses and Dissertations (Comprehensive)

As new techniques have been introduced, specifically the possibility of complete genome sequencing, better methods of defining bacterial species have also been proposed. One of the most recently proposed methods, using bioinformatic techniques, is to calculate the average nucleotide identity (ANI) between the homologous genome segments of different isolates. Another method for species discrimination that has been tested successfully is the similarity of DNA compositional signatures. However, in a recent update, DNA signatures split the available Escherichia coli complete genomes into three groups. To check if this result was consistent with such genomes belonging to different species, we tested methods …

Awareness Of Genetic Predispositions That Increase The Risk Of Breast Cancer, Carly Huber

Honors Undergraduate Theses

Breast cancer is the most commonly diagnosed cancer in women in the United States and is the leading cause of cancer-related death among women worldwide. Certain demographics, such as racial/ethnic, age, and gender groups, are underrepresented in breast cancer studies. This lack of representation results in issues with creating genetic tests, as variants associated with those groups are not being detected. Furthermore, these underrepresented demographics are receiving a worse prognosis than those that are overrepresented in research. This study aimed to understand how informed the understudied racial/ethnic, gender, and age populations are regarding breast cancer and genetic testing compared to …