Genetics and Genomics Commons^™

Evolutionary Inference From Admixed Genomes: Implications Of Hybridization For Biodiversity Dynamics And Conservation, Tyler Chafin

Graduate Theses and Dissertations

Hybridization as a macroevolutionary mechanism has been historically underappreciated among vertebrate biologists. Yet, the advent and subsequent proliferation of next-generation sequencing methods has increasingly shown hybridization to be a pervasive agent influencing evolution in many branches of the Tree of Life (to include ancestral hominids). Despite this, the dynamics of hybridization with regards to speciation and extinction remain poorly understood. To this end, I here examine the role of hybridization in the context of historical divergence and contemporary decline of several threatened and endangered North American taxa, with the goal to illuminate implications of hybridization for promoting—or impeding—population persistence in …

Chasing The Genetics Of Ascites In Broilers Using Whole Genome Resequencing, Alia Parveen

Graduate Theses and Dissertations

We are using whole genome resequencing to identify chromosomal regions associated with resistance or susceptibility to ascites, a form of pulmonary hypertension syndrome, meat-type chickens. Previous Genome Wide Association Studies (GWAS) based on Single Nucleotide Polymorphisms (SNPs) have identified regions on chromosomes 2, 9 and Z. Despite several GWAS and further genotyping, there are no reliable or potential markers for ascites phenotype. We have completed screening of Copy Number Variations (CNVs) and Single Nucleotide Polymorphisms in ascites resistant and susceptible birds from the relaxed, REL, line derived from a commercial elite broiler line. DNA samples from resistant and susceptible birds …

The Effects Of Foot And Udder Scoring On Cow And Calf Performance, Clayton Lee Mcguire

Graduate Theses and Dissertations

Foot soundness and udder conformation are essential for longevity in beef cattle. The objective of this study was to investigate the effects of foot angle (FA), claw set (CS), teat size (TS) and udder suspension (US) scores on cowherd performance. Data were analyzed for 1,685 observations on Angus-based cows over a four-year period. At weaning FA, CS, TS, and US were evaluated. Scores are based on nine-point scales. A score of one indicates straight pasterns, divergent toes, enlarged bottle shaped teats, and absence of a median suspensory ligament; nine indicates weak pasterns, curled toes, small symmetrical teats, and a tight …

Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford

Graduate Theses and Dissertations

The economic impact of infectious bovine keratoconjunctivitis (IBK) has been documented in many parts of the world. Many researchers have observed that prevention of this disease is very difficult given current methodologies. This is primarily due to the multifactorial nature of this disease. The objective of this dissertation was to determine the impact of IBK on calf performance and estimate genetic parameters, heritability and estimated breeding values for IBK susceptibility. Data were analyzed using PROC GLIMMIX of SAS; while genetic parameters were estimated using a linear animal model for both single- and two-traits through MTDFREML. Additional evaluations calculated heritability using …

Functional Importance Of Lipin Phosphorylation, Stephanie Elizabeth Hood

Graduate Theses and Dissertations

Highly conserved throughout evolution, lipins are dual functioning proteins found from yeast to humans. Functioning in the cytoplasm as phosphatidate phosphatase enzymes (PAP), lipins produce diacylglycerol that serves as a precursor for neutral fats and membrane phospholipids. Alternatively, nuclear lipins are responsible for the regulation of metabolic genes. Interestingly, both the mammalian lipin 1 paralog and the single Drosophila Lipin ortholog are highly phosphorylated proteins. Target of rapamycin (TOR) has previously been identified as one of the kinases that controls the subcellular localization of both lipin 1 and Drosophila Lipin. However, other serine and threonine kinases are predicted to be …

Investigating Growth Performance And Intestinal Barrier Integrity In Heat-Stressed Modern Broilers And Their Ancestor Jungle Fowl, Travis Tabler

Graduate Theses and Dissertations

Heat stress (HS) has a negative effect on poultry production sustainability due to its adverse consequence on bird welfare, health, growth, and mortality. Although modern broilers have greater gut mass and higher energy use efficiency than unselected birds, they are more vulnerable to HS that induces “leaky gut syndrome,” or increased intestinal permeability. The aim of the current study was to determine the effect of HS on growth performance and gut barrier integrity in three modern broiler lines and their ancestor the Jungle Fowl. Four chicken populations including Giant Jungle Fowl (JF), Athens Canadian Random Bred (ACRB), 1995 Arkansas Random …

The Functional And Structural Analysis Of Drosophila Robo2 In Axon Guidance, Lafreda Janae Howard

Graduate Theses and Dissertations

In animals with complex nervous systems such as mammals and insects, signaling pathways are responsible for guiding axons to their appropriate synaptic targets. Importantly, when this process is not successful during the development of an organism, outcomes include catastrophes such as human neurological diseases and disorders. It is vital to determine the underlying causes of such diseases by understanding the development of the nervous system. There are many pathways that have been identified to play a role in this, however, we lack an understanding of how these pathways can promote such diverse outcomes in different populations of neurons. These pathways …

Rescue And Reestablishment Of Chicken Models For Spontaneously Occurring Hashimoto’S Thyroiditis And Systemic Sclerosis/Scleroderma, Joseph Zolton Hiltz

Graduate Theses and Dissertations

The loss of biodiversity is a topic gaining popularity both in the political and scientific forums. Nearly 30 years ago researchers and politicians congregated in Rio de Janeiro (1992) to attend the first Earth Summit. It was the first meeting of its kind discussing the tangible pressing consequences of biodiversity loss as well as the potential long term ramifications. Many of the countries represented at this summit implemented short and long term plans in order to accurately measure losses of biodiversity as well as establishing organizations to help diagnose and remedy the current problems at hand. These new organizations and …

De Novo Development And Characterization Of Tetranucleotide Microsatellite Loci Markers From A Southeastern Population Of The House Finch (Haemorhous Mexicanus), Edgar E. Sanchez, J Dylan Maddox, Douglas G. Barron

Journal of the Arkansas Academy of Science

Microsatellites are short tandem repeats (e.g. TAGATAGA) of base pairs in a species’ genome. High mutation rates in these regions produce variation in the number of repeats across individuals that can be utilized to study patterns of population- and landscape-level genetics and to determine parentage genetically. In this project our objective was to develop microsatellite markers for the House Finch, Haemorhous mexicanus. This species has become one of the most well-studied species of songbirds due to its unique geographical, evolutionary, and epidemiological history. Using mist-nets we captured birds on the Arkansas Tech University campus and collected blood samples to …

Genetic And Epigenetic Investigations On Pulmonary Hypertension Syndrome In Meat Type- Chickens, Khaloud Alzahrani

Graduate Theses and Dissertations

This dissertation presents a collection of studies that investigate the genetic and epigenetic associations to ascites phenotype in broiler chickens. Ascites is a significant metabolic disease associated with fast-growing meat-type chickens (broilers) and is a terminal result of pulmonary hypertension syndrome PHS. It is a multi-factorial syndrome caused by interactions between genetic, physiological, environmental, and managemental factors. It was estimated that ascites accounts for losses of about US$1 billion annually worldwide and for over 25% of broilers mortality. Although traditional and molecular genetic methods in the selection and in performance improvements, has greatly reduced ascites frequency, yet it has not …

Evaluation Of Genetic And Environmental Influences On Broiler Meat Quality, Sara Katherine Orlowski

Graduate Theses and Dissertations

The effect of both genetic and environmental influences on broiler meat quality were evaluated over three experiments. Selection response was assessed for broiler lines selected for high (HBY4) and low (LBY4) four day percentage breast yield which were formed from a random bred control (RAN). A modern random bred population (MRB) created in 2015 was evaluated for differences in 4 day percentage breast yield and the resulting differences in the incidence and severity of the woody breast and white striping myopathies. Additionally, the use of embryonic thermal manipulation to impact cell division and early caloric feed restriction to slow growth …

The Evaluation Of Genetic And Phenotypic Differences Associated With Short Term Selection Of Four Different Feed Efficiency Strategies In Japanese Quail, Alex David Gilley

Graduate Theses and Dissertations

The concept of feed efficiency (FE), one unit of feed required to improve one unit of desired output, is relatively simple. However multiple outputs are desired in a commercial poultry breeding program, resulting in the need for nutrients to be partitioned in a particular manner. At the broadest level, nutrients are partitioned between production and maintenance requirements. The requirements for production and maintenance varies between birds. It is the poultry breeder’s responsibility to select individuals most aligned with the breeding objective. Irrespective of the breeding objective, various related and non-related traits influence a bird’s FE. To effectively improve FE, the …

Investigation Of Bacterial Taxa As Biomarkers Of Fescue Toxicosis And Heat Stress In Grazing Beef Cows, Sarah Katherine Chewning

Graduate Theses and Dissertations

Fescue toxicosis in grazing beef cattle is caused by consumption of Ergot alkaloids associated with tall fescue (toxic fescue) and is responsible for substantial economic loss to the U.S. beef industry. Cattle consuming toxic fescue suffer adverse physiological responses, such as: hyperthermia, increased respiration rate (RR), poor reproduction and growth performance. Other adverse responses to fescue toxins include the retention of a winter hair coat and vasoconstriction in the extremities, which can lead to tissue necrosis. Identifying cattle with reduced susceptibility to fescue toxins would allow for efficient use of fescue pastures; thus, the objectives of this thesis was to: …

Functional Polymorphisms Of Alcohol Metabolism Genes And Their Protection Against Alcoholism Via Gene Therapy: A Systematic Review, Olivia Tzeng

Psychological Science Undergraduate Honors Theses

Around 45% of East Asians are unable to fully metabolize ethanol due to functional

polymorphisms of alcohol metabolism genes, specifically alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). These individuals display high levels of toxic blood acetaldehyde when consuming alcohol, causing symptoms such as tachycardia, vomiting, and flushing. The studies included in this review examine how functional polymorphisms of ADH and ALDH protect against alcoholism in addition to how polymorphisms can be utilized as protection against alcoholism via gene therapy. The studies included found that carriers of the ADH and ALDH polymorphisms were 66 to 99% genetically protected against alcoholism. Through …

Effects Of Mitochondrial Nadp+-Dependent Isocitrate Dehydrogenase Deficiency On Fructose-Induced Obesity In Mice, Allison Michelle Montalbano, Kaleigh Elizabeth Beane

Human Nutrition and Hospitality Management Undergraduate Honors Theses

Obesity prevalence in the United States continues to increase and is associated with health consequences such as type 2 diabetes, hypertension, atherosclerosis, and hyperlipidemia. Among many contributing factors to obesity, fructose may be one of the major reasons as it disrupts the antioxidant system thereby resulting in an accumulation of reactive oxidative species and leading to obese conditions. The enzyme, isocitrate dehydrogenase 2 (IDH2), reduces nicotinamide adenine dinucleotide phosphate from the TCA Cycle, hence might be implicated with not only energy metabolism but also cellular redox homeostasis. Therefore, the hypothesis was that IDH2 deficiency in mice would exacerbate hepatic lipid …

Phylogeny Of The Orangethroat Darter (Etheostoma Spectabile) Species Complex In The Ozark Highlands Of Arkansas, Mckenna George

Animal Science Undergraduate Honors Theses

Darters are small, benthic fishes that live in freshwater rivers and streams and belong to the family Percidae. Pleistocene glaciations fragmented many darter species, resulting in speciation, but new species are often hard to detect if they are morphologically identical to pre-existing species. Intraspecific hybridization and resulting introgression, which occur frequently in glaciated areas, further complicate identification by introducing heterospecific genomes into mitochondrial DNA, making it difficult to accurately resolve phylogenetic relationships. The results of Bossu and Near’s 2009 study highlight this issue, showing a large degree of incongruence between mitochondrial and nuclear gene trees.

This study analyzed samples from …

Optimizing Genetic Manipulation Of Methanogens Through Faster Cloning Techniques, Merrisa Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

Methanogenesis is the biological production of methane. Only anaerobic archaea known as methanogens are capable of such a metabolic feat. They have strict living conditions and substrate sources which determine their rate of metabolism. This is of particular importance from a greenhouse gas reduction perspective or biogas capturing perspective. One of the best ways to optimize methanogen methane production is via genetic manipulation. The current procedures are timely though, therefore a faster cloning processes should be developed. The objective of this study was to optimize a premade genetic transformation kit known as the Gibson Kit. The Gibson Kit was supposed …

Unravelling The Layers Of Cell Wall Synthesis And Function In Rice, Ritu Mihani

Graduate Theses and Dissertations

The plant cell wall is of critical importance to plant growth and survival, functioning in maintaining structural integrity, supporting cell expansion, and acting as the first line of defense in response to biotic and abiotic stresses. The major components of the cell wall are cellulose, hemicelluloses, lignin, and pectin. Recent focus on the transcriptional machinery regulating cell wall biosynthesis in plants has revealed many key transcription factors responsible for orchestrating cell wall deposition. However, many of these TFs act redundantly and work coherently with a suite of TFs to activate the cell wall biosynthetic machinery. Heterologous expression of TFs is …

Involvement Of The Ino80 Complex In Chromosome Segregation, Jesus Moreno

Graduate Theses and Dissertations

Chromatin remodeling complexes are multi-protein complexes that regulate the dynamics of the nucleosomes in the genome. The INO80 chromatin remodeling complex participates in varied biological processes such as: transcription, DNA repair, DNA replication and chromosome integrity. It catalyzes the eviction of the H2A.Z variant histone as well as whole nucleosome eviction. This complex is comprised of 15 subunits and the contribution of each to chromosome segregations remains unknown. To evaluate the contribution of each subunit to chromosome segregation, we tested deletion mutants of the non-essential subunits for DNA content and benomyl sensitivity. Also, we assessed members of the SWR1 and …

Phylogeny And Evolutionary Genomics Of Non-Photosynthetic Diatoms, Anastasiia Onyshchenko

Graduate Theses and Dissertations

Diatoms are prolific photosynthesizers responsible for some 20% of global primary production. In real terms, the oxygen in one of every five breaths traces back to photosynthesis by marine diatoms. Among the tens of thousands of diatom species, a small handful of colorless diatom species in the genus Nitzschia have lost photosynthesis altogether and rely exclusively on extracellular organic carbon for growth. I used DNA sequence data to reconstruct the phylogeny of this group, and found that nonphotosynthetic diatoms are monophyletic, indicating that photosynthesis was lost just one time over the course of some 200 million years of diatom evolution. …

Polymorphisms Of Bovine Hsp90 And Their Implications In Beef Cattle Productivity, Glynn G. Smith

Animal Science Undergraduate Honors Theses

Production of beef cattle represents a $60 billion industry in the United States (USDA, 2015). The American beef cattle industry loses an estimated $370 million annually due to heat stress (St-Pierre, 2003). As of 2003, this was equal to nearly 99 million pounds of beef lost (USDA, 2015). The average American consumed roughly 65 pounds of beef in 2003; this means that the 99 million pounds of beef lost to heat stress would have been enough to feed approximately 1.5 million Americans for an entire year (Barclay, 2012).

Evolutionary Conservation Of Midline Repulsion By Robo Family Receptors In Flies And Mice, Allison Loy

Biological Sciences Undergraduate Honors Theses

As the nervous system develops in animal embryos, neuronal axons are guided to their synaptic targets by extra cellular cues that signal through axon guidance receptors expressed on the surface of the axon. In animals with bilateral symmetry, one of the important decisions made by nearly every axon in the embryonic nervous system is whether to stay on its own side of the body, or to cross the midline and connect to cells on the opposite side. The Roundabout (Robo) family is an evolutionarily conserved group of axon guidance receptors that regulate midline crossing in a wide range of animal …

Bayesian Network Modeling And Inference Of Gwas Catalog, Qiuping Pan

Graduate Theses and Dissertations

Genome-wide association studies (GWASs) have received an increasing attention to understand genotype-phenotype relationships. The Bayesian network has been proposed as a powerful tool for modeling single-nucleotide polymorphism (SNP)-trait associations due to its advantage in addressing the high computational complex and high dimensional problems. Most current works learn the interactions among genotypes and phenotypes from the raw genotype data. However, due to the privacy issue, genotype information is sensitive and should be handled by complying with specific restrictions. In this work, we aim to build Bayesian networks from publicly released GWAS statistics to explicitly reveal the conditional dependency between SNPs and …

Transcriptome-Based Gene Networks For Systems-Level Analysis Of Plant Gene Functions, Chirag Gupta

Graduate Theses and Dissertations

Present day genomic technologies are evolving at an unprecedented rate, allowing interrogation of

cellular activities with increasing breadth and depth. However, we know very little about how the

genome functions and what the identified genes do. The lack of functional annotations of genes

greatly limits the post-analytical interpretation of new high throughput genomic datasets. For plant

biologists, the problem is much severe. Less than 50% of all the identified genes in the model plant

Arabidopsis thaliana, and only about 20% of all genes in the crop model Oryza sativa have some

aspects of their functions assigned. Therefore, there is an …

Identifying Genetic Factors Influencing Sperm Mobility Phenotype In Chicken Using Genome Wide Association Studies, Primordial Germ Cell Transplantation, And Rnaseq., Sohita Ojha

Graduate Theses and Dissertations

Sperm mobility is a major determinant of male fertility in chicken. In spite of low heritability of reproductive traits, sperm mobility has high heritability index which suggests presence of quantitative trait loci (QTLs) governing the trait. Our research focused on three objectives: i) to identify the QTLs affecting low mobility phenotype in chicken, ii) to understand the impact of Sertoli-cells and germ cells interactions in influencing the mobility phenotype and iii) to identify the genes and gene networks differentially expressed in male and female PGCs. To detect the QTLs, genome wide association studies (GWAS) was conducted which revealed the presence …

Role Of Incompatibility Group 1 (Inci1) Plasmid-Encoded Factors On Salmonella Enterica Antimicrobial Resistance And Virulence, Pravin Raghunath Kaldhone

Graduate Theses and Dissertations

Foodborne illnesses are a leading cause of infectious diseases in the world. Among enteric organisms Salmonella is a key pathogen. It’s high prevalence in poultry and other food-animal sources make it imperative to study. Salmonella has the ability to modify its genetic content with help of mobile genetic elements such as plasmids. Incompatibiltiy group 1 (IncI1) plasmids are commonly reported in Salmonella. This study evaluates role on IncI1 plasmids in antimicrobial resistance and virulence in Salmonella. Genetic determinants of resistance and virulence are noted among our IncI1-containing Salmonella isolates. These genetic elements are also transferable and reported to carry respective …

Identifying Three-Way Gene Interactions From Microarray Data Using Kolmogorov-Smirnov And Cross-Match Tests, Shubhashree Khadka

Graduate Theses and Dissertations

Human gene network is much more complex than just pairwise interaction among the genes. Zhang et al. [6] extracted microarray data from International Genomics Consortium (IGC), and presented the detection of three-way gene interactions in their paper using Fisher’s z-transformation test. Three-way gene interactions are closer than pairwise correlations in representing the complex gene structures. Additionally, it was more tractable than assessing four or more gene interactions. In this paper, we are simulating different models where Fisher’s test might not be as effective. Zhang et al.’s approach utilized Pearson’s correlation coefficients and involved detection of linear interactions only. Since gene …

Genome Wide Association And Next Generation Sequencing Approaches To Map Determinants Of Ascites In Broiler Chickens, Shatovisha Dey

Graduate Theses and Dissertations

These studies have investigated different candidate genomic regions for their contributions to ascites in broilers. Ascites syndrome is a manifestation of idiopathic pulmonary arteriole hypertension that concerns the poultry industry worldwide. Investigations have demonstrated the disease to be genetically regulated and to exhibit moderate to high heritabilities. Although previous studies have indicated a few chromosomes to be involved with ascites, no genes have been identified to date with direct links to the disease. This dissertation presents a collection of studies that determine the genomic and genetic interactions for regions on chromosome 2 and 9 for ascites phenotypes in broiler chickens. …

Comprehensive Assessments Of The Genetic Determinants In Salmonella Typhimurium For Fitness Under Host Stressors: Oxidative Stress And Iron Restriction, Sardar Abdullah

Graduate Theses and Dissertations

Salmonella is an intracellular pathogen that infects a wide range of hosts. The infected host utilizes reactive oxygen species (ROS) and iron-restriction to eliminate the pathogen. We used proteogenomics to determine the candidate genes and proteins that have a role in resistance of S. Typhimurium to H2O2. For Tn-seq, a highly saturated Tn5 library was grown in vitro under either 2.5 (H2O2L) or 3.5 mM H2O2 (H2O2H). We identified two sets of overlapping genes that are required for resistance of S. Typhimurium to H2O2L and H2O2H, and the results were validated via phenotypic evaluation of 50 selected mutants. The enriched …

Phenotypic Variation And Genetic Purity Of The Original 'Prime-Jim®' X 'Arapaho' Population, Loren M. Luther

Horticulture Undergraduate Honors Theses

In 2013, Castro et al., produced the first linkage map for primocane-fruiting blackberries using the cross ‘Prime-Jim®’ x ‘Arapaho.’ This mapping population has been maintained since the original experiment with the hopes of conducting future studies. Further research was determined to be needed on the population to better characterize additional phenotypic traits, and since nine years had passed since the seedlings were established, there was a need to assess the continued genetic purity of the population using molecular methods. Phenotypic data was collected to analyze the variation of the population including soluble solids content, titratable acidity, average weight, shape, and …