Life Sciences Commons^™

Physiologic And Pathologic Profiling Of Clonal Variations, Wing Hing Wong

Arts & Sciences Electronic Theses and Dissertations

This thesis sought to provide a better understanding of clonality in various malignant and non-malignant settings using a variety of genomic analytical tools. Clonality is pre-defined as the presence of a mixed population of cells in which each sub-population has distinct somatic mutation profile. It is a common feature in cancers where subpopulations of cells arise as a result of independent, yet continual acquisition of somatic mutations. The clonal architecture of cancers can be used as a diagnostic and prognostic biomarker as well as to monitor disease progression or resolution. Besides cancer, clonal variability and expansion is also implicated in …

Multi-Omic Understanding Of The Evolution Of Xenobiotic Tolerance In Bacterial Isolates And Communities, Tayte Paul Campbell

Arts & Sciences Electronic Theses and Dissertations

Xenobiotic compounds are any chemicals that are released into an environment by human action and that occur at concentrations higher than found naturally. Xenobiotics, including aromatic compounds and antibiotics, are recalcitrant to degradation because they are often toxic or mutagenic. Despite this toxicity, bacteria account for a large portion of xenobiotic degradation in the environment. Bacteria are able to adapt to these foreign chemicals, gaining increased levels of tolerance and increased rates of xenobiotic degradation. On the strain level, increased tolerance can be caused by mutations in individual cells or through the acquisition of genes from other cells. At the …

Quantifying The Predictability Of Evolution At The Genomic Level In Lycaeides Butterflies, Samridhi Chaturvedi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Stephen Jay Gould, a great scientist and evolutionary biologists, suggested that if we could replay the tape of life, we would not have observed similar course of events because evolution is stochastic and if affected by several events. Since then, the possibility that evolution is repeatable or predictable has been debated. Studies using large-scale evolution experiments, long-term data for individual populations, and controlled experiments in nature, have demonstrated phenotypic and genetic convergence in several taxa. These studies suggest that despite some randomness, predictable evolutionary patterns can emerge on a large temporal and spatial scale. However, a few cases also exist …

Mixing It Up: The Impact Of Episodic Introgression On The Evolution Of High-Latitude Mesocarnivores, Jocelyn P. Colella

Biology ETDs

At high latitudes, climatic oscillations have triggered repeated episodes of organismal divergence by geographically isolating populations. For terrestrial species, extended isolation in glacial refugia – ice-free regions that enable terrestrial species persistence through glacial maxima – is hypothesized to stimulate allopatric divergence. Alternatively, upon glacial recession, divergent populations expanded from independent glacial refugia and often contacted other diverging populations. In the absence of reproductive isolating mechanisms, this biogeographic process may trigger hybridization and ultimately, gene flow between divergent taxa. My dissertation research aims to understand how these episodic periods of isolation and contact have impacted the evolution of high latitude …

An Assessment Of Combinatorial Transcription Factor Activity At P53 Enhancer Elements, Sylvia Kuang

Biological Sciences

Certain non-coding DNA sequences in the eukaryotic genome regulate gene expression. These non-coding regulatory regions, including promoters and enhancers, are controlled by the binding of multiple transcription factors which act together to regulate gene transcription. The number of potential transcription factor combinations regulating any gene presents a massive experimental challenge. One well-known transcription factor, p53, activates multiple transcription pathways involved in tumor suppression, primarily through engagement with enhancers. p53 is one member of a paralogous transcription factor family, which includes the factor p63. Whereas p53 is involved in tumor suppression, p63 is a transcription factor responsible for maintaining epithelial cell …

Genomics Based Approaches To Fungal Evolution, Aaron J. Robinson, Donald O. Natvig

Biology ETDs

Advances in DNA sequencing and data analysis make it possible to address questions in population genetics and evolution at the genomic level. Fungi are excellent subjects for such studies, because they are found in diverse environments, have short generation times, can be maintained in culture and have relatively small genomes. My research employed genetic approaches using a variety of sequencing technologies and methods of analysis to explore questions in fungal evolution.

In one study, I explored the genetics behind differences in thermotolerance between isolates of Neurospora discreta from Alaska and New Mexico. Isolates from the two states exhibited differences in …

High-Throughput Cultivation Of Bacterioplankton From The Gulf Of Mexico And Genomics Of The First Cultured Ld12 Representative, Michael Winslow Henson

LSU Doctoral Dissertations

Cultivation of microorganisms facilitates characterization of metabolism, interspecies dependencies, virus-host interactions, and other information necessary to resolve the functions and distribution of individual taxa. However, the metabolic and physiological capacities for the majority of microbes remains unresolved because of the lack of cultivated representatives for many groups limits our ability to test cultivation-independent observations. The Northern Gulf of Mexico offers a diversity of ecosystems under the continuous threat from natural and anthropogenic disturbances, yet little is known about its native bacterioplankton community. This dissertation sought to use high-throughput cultivation over three-years at six sites to isolate important coastal bacteria to …

Evidence-Based Practice Self-Study Education Program For Staff Nurses On Genomics, Nancy L. Norman-Marzella

Walden Dissertations and Doctoral Studies

Nurses routinely obtain genomic data when collecting family health histories. However, they report low confidence in their knowledge and understanding of genomics and the genetically engineered medications prescribed for their patients. The purpose of this project was the development and implementation of an evidence-based online education program about genetics and genomics to increase the nurses' understanding and ability to provide competent care for their patients receiving treatments based on the science of genomics. Knowles's principles of adult learning theory guided the development and delivery of the online education project to 12 medical-surgical registered nurses employed in a hospital in the …

Characterization Of Epigenetic Plasticity And Chromatin Dynamics In Cancer Cell Models, Diana Lea Gerrard

Graduate College Dissertations and Theses

Cancer progression is driven by cumulative changes that promote and maintain the malignant phenotype. Epigenetic alterations are central to malignant transformation and to the development of therapy resistance. Changes in DNA methylation, histone acetylation and methylation, noncoding RNA expression and higher-order chromatin structures are epigenetic features of cancer, which are independent of changes in the DNA sequence. Despite the knowledge that these epigenetic alterations disrupt essential pathways that protect cells from uncontrolled growth, how these modifications collectively coordinate cancer gene expression programs remains poorly understood. In this dissertation, I utilize molecular and informatic approaches to define and characterize the genome-wide …

Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks

Theses and Dissertations--Biology

Plants are threatened by global change, increasing variability in weather patterns, and associated abiotic stress. Consequently, there is an urgent need to enhance our ability to predict plant community dynamics, shifts in species distributions, and physiological responses to environmental challenges. By building a fundamental understanding of plant stress tolerance, it may be possibly to protect the ecological services, economic industries, and communities that depend on plants. Dehydration tolerance (DhT) is an important mechanism of water stress tolerance with promising translational applications. Here, I take advantage natural variation in DhT to gain a deeper insight into this complex trait. In addition, …

Cisco Science: Using Omics To Answer A Range Of Key Questions, Hannah Lachance

Graduate College Dissertations and Theses

Coregonines, including cisco (Coregonus artedi), kiyi (Coregonus kiyi), and bloater (Coregonus hoyi), are a focus for prey fish conservation and restoration efforts throughout the Laurentian Great Lakes. However, fundamental questions about coregonine ecology and genetics remain. For example, we know little about how the early life stages of coregonines respond to environmental change at either the genotypic or phenotypic level. We also have limited knowledge about how to identify different species at the larval stage and the genetic relationships among species, which makes the different species difficult to study at the larval stage. To increase the probability for success in …

Natural Selection For Disease Resistance In Hybrid Poplars Targets Stomatal Patterning Traits And Regulatory Genes., Karl Christian Fetter

Graduate College Dissertations and Theses

The evolution of disease resistance in plants occurs within a framework of interacting

phenotypes, balancing natural selection for life-history traits along a continuum of

fast-growing and poorly defended, or slow-growing and well-defended lifestyles. Plant

populations connected by gene flow are physiologically limited to evolving along a

single axis of the spectrum of the growth-defense trade-off, and strong local selection

can purge phenotypic variance from a population or species, making it difficult to

detect variation linked to the trade-off. Hybridization between two species that have

evolved different growth-defense trade-off optima can reveal trade-offs hidden in either

species by introducing phenotypic and …

Population Structure And Connectivity Of A Groundwater Crustacean Across Northwestern Montana Aquifers, Megan N. Ritter

Master’s Theses

Floodplain aquifer systems are diverse and heterogenous ecosystems that serve many ecological functions, including habitat provision to a range of groundwater species. The Flathead River system of northwestern Montana is home to many floodplain aquifers of great ecological importance to the region. The basic biology, population structure, and dispersal patterns of obligate groundwater organisms that reside within the aquifers of the Flathead are still largely unknown. In this study, we investigate the population structure of one such taxon, an undescribed species of the amphipod genus Stygobromus. For our low-coverage RADseq dataset, we tested the suitability of three different analysis …

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 …