Life Sciences Commons^™

Evaluating The Effectiveness Of The Internal Transcribed Sequences (Its) As Dna Barcodes To Estimate Fungal Diversity, Jailisa Linares

All HCAS Student Capstones, Theses, and Dissertations

Universal phylogenetic markers such as the nuclear ribosomal internal transcribed sequences (ITS), specifically ITS1 and ITS2, are routinely used to estimate fungal diversity in environmental samples. However, numerous studies report differences in the performance and efficacy of ITS1 and ITS2 in documenting fungal diversity. To better understand the implications of using ITS1 versus ITS2, a comprehensive representation of the diverse fungal taxa was necessary to conduct a meta-analysis of their use across multiple fungal taxa. In order to address this, a thorough literature review was conducted to compare and contrast the use of ITS1 and ITS2 as effective DNA barcodes. …

Development Of Graphical Models And Statistical Physics Motivated Approaches To Genomic Investigations, Yashwanth Lagisetty

Dissertations & Theses (Open Access)

Identifying genes involved in disease pathology has been a goal of genomic research since the early days of the field. However, as technology improves and the body of research grows, we are faced with more questions than answers. Among these is the pressing matter of our incomplete understanding of the genetic underpinnings of complex diseases. Many hypotheses offer explanations as to why direct and independent analyses of variants, as done in genome-wide association studies (GWAS), may not fully elucidate disease genetics. These range from pointing out flaws in statistical testing to invoking the complex dynamics of epigenetic processes. In the …

Evolution Of Targeted Therapy Resistance In Eml4-Alk Positive Non-Small Cell Lung Cancer, Robert Vander Velde

USF Tampa Graduate Theses and Dissertations

Targeted therapies have emerged as potent treatments that lead to the remission of many tumors. However, they rarely cure cancers in advanced, metastatic settings. This is due to the evolution of resistance, which in turn can be ascribed to the survival of small subpopulations of tolerant and/or resistant cells. Here we investigated the evolution of resistance to EML4-ALK inhibitors in non-small cell lung cancer (NSCLC) and demonstrated that resistance evolves gradually, from unique pre-treatment sub-populations, as multiple resistance mechanisms accumulate in a Darwinian fashion. Despite accumulating multiple changes, cells evolved, in parallel, toward similar inhibitor specific phenotypes. Evolving cells have …

The Role Of Nutrition And Hormone Signaling In Extended Larval Development And Obesity In Starvation-Selected Drosophila Melanogaster, Jennifer M. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

Brief periods of starvation are a common stressor that most animals encounter in the wild and must be able to survive in order to maximize their fitness. Starvation resistance of the adult fruit fly, Drosophila melanogaster, is thought to be primarily conferred by adult fat stores, body size, metabolic rate, behavior, and activity levels. Additionally, flies selected for starvation resistance also often show delayed pupariation, which is usually indicative of altered hormone signaling. How starvation selection extends development and if it contributes to adult starvation resistance remains incompletely studied. Identifying the targets of starvation selection that cause extended development and …

The Distribution In Native Populations From Mexico And Central America Of The C677t Variant In The Mthfr Gene, Lucio A. Reyes

USF Tampa Graduate Theses and Dissertations

Objectives: To explore evolutionary hypotheses for the high frequencies of a substitution in the methylenetetrahydrofolate reductase (MTHFR) gene, in Mexican and Central American Indigenous populations.

Materials and methods: We obtained allele frequencies for the C677T variant in the MTHFR gene and ecological information for 37 indigenous samples from Mexico and Central America. We calculated Hardy–Weinberg equilibrium and computed Fst statistics. We computed correlations between the samples' allele frequencies and ecological and geochemical variables.

Results: Many of the samples have extremely high frequencies of the T allele (q̄ = 0.62, median = 0.66). In this region, the frequency of the T …

Pillars Of The Nutrition Transition: The Global Impacts Of Ultra-Processed Foods And Beverages On Overweight And Obesity And National Nutrient Supplies, Jacob Eaton

Arts & Sciences Electronic Theses and Dissertations

Malnutrition in some form impacts nearly one-third of the global population. Across the world, countries are undergoing the Үutrition transitionӠfrom traditional and largely unprocessed diets to Western-style, energy-dense diets. At the same time, rates of overweight and obesity and diet-related chronic diseases continue to climb. Ultra-processed foods (UPF), sugar-sweetened beverages (SSB), and vegetable oils are three of the foods driving the nutrition transition. This dissertation calculates changes in the global food supply between 1961 and 2013 and quantifies the influence of UPF and SSB (as measured through sales) on national nutrient supplies between 2005 and 2013 and trends in adult …

Evolutionary Convergence Of The Caffeine Biosynthetic Pathway In Chocolate Followed Duplication Of A Constrained Ancestral Enzyme, Andrew J. O'Donnell

Masters Theses

Caffeine biosynthesis is widely distributed in flowering plants and requires three consecutive methylation steps of xanthine alkaloids. Genes that have previously been reported to participate in the multi-step pathway in Coffea sp. (coffee) and Camellia sinensis (tea) encode members of the SABATH family of methyltransferases. Two genes highly expressed in fruits of Theobroma cacao (cacao) are orthologous to the caffeine genes in tea and appear to have diversified following gene duplication. Biochemical characterization of the enzymes (XMTs) encoded by these genes strongly suggest an unprecedented major pathway to theobromine, a precursor to caffeine. These findings imply that caffeine biosynthesis evolved …

Proximate And Evolutionary Insights Into The Epigenetics Of Posttraumatic Stress Disorder, Levent Sipahi

Wayne State University Dissertations

Posttraumatic stress disorder (PTSD) is an important medical and social condition. Although the vast majority of individuals are exposed to traumatic events within their lifetime, a minority subsequently develop diagnosable PTSD. What underlies differential risk and resiliency in the face of trauma is an ongoing research and clinical question with implications for prevention and treatment. Recent work has revealed a putative role of epigenetic variation and modification - most notably DNA methylation - in the etiology of PTSD. That DNA methylation is stable, yet modifiable in response to lived experiences, makes it a strong candidate to mechanistically explain the ontogeny …

Functional Analysis Of Corazonin And Its Receptor In Drosophila Melanogaster, Kai Sha

Doctoral Dissertations

Corazonin (Crz) is an amidated undecapeptide originally isolated from the American cockroach. It has been shown to affect diverse physiological functions in a species-specific manner. However, the functionality of Crz in Drosophila melanogaster has not yet been determined. To gain insight into the role of Crz signaling in vivo, Crz and CrzR null alleles were obtained by transposable element mobilization. Flies carrying a deficiency uncovering Crz and pr-set7 loci were generated via P-element excision, and the latter was rescued by wild-type pr-set7 transgene. A mutation of Crz receptor (CrzR) was generated by Minos-element mobilization from …