Genetics Commons^™

Sorghum Grain Secondary Metabolites And Underlying Genetics To Reduce Foodborne Pathogens In Poultry, Maria A. Conti

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The rise in antibiotic-resistant pathogens poses a threat to the poultry industry's ability to maintain animal health, prompting growing interest in alternatives to synthetic antibiotics. The use of non-tannin sorghum [Sorghum bicolor (L.) Moench] in poultry rations offers a valuable alternative, as this cereal grain has a high bioactive profile that can provide health benefits, including antimicrobial (AM) activity. The scope of this study was to examine the AM potential of non-tannin sorghum grain against Clostridium perfringens, a major foodborne pathogen that negatively impacts poultry health and production. To that end, the inhibitory effects of a non-tannin sorghum …

Precursor Rna Properties Driving Cryptic 3’ Splice Site Selection In Sf3b1 Mutant Malignancies, Austin A. Herbert

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SF3B1 is a core component of the spliceosome involved in branch point recognition and 3’ splice site selection. SF3B1 is commonly mutated in myelodysplastic syndromes and other blood cancers with the K700E mutation being the most frequent. This mutation of SF3B1 induces cryptic 3’ splice site activation in hundreds of genes. Introduction of such cryptic 3’ splice sites can shift the reading frame of protein coding transcripts, causing the transcript to be tagged for nonsense-mediated decay or resulting in the production of a truncated protein. Both these scenarios can lead to down-regulated protein expression. Sequence and structural properties of precursor …

Abnormal Trafficking And Processing Of Multiple Matrix Metalloproteinases Drive Cartilage Defects In Congenital Disorders Of Glycosylation, Chia-Lun Wu

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Congenital Disorders of Glycosylation (CDG) are rare metabolic diseases caused by defects in glycosylation. Despite identification of over 200 CDG types, the mechanisms linking glycosylation defects to diverse clinical phenotypes remain unclear. This dissertation uses zebrafish models of PMM2-CDG and STT3-CDG to redefine CDG pathogenesis, shifting from a simple glycan deficiency model to one involving disrupted cellular spatial organization.

We identify a protease-dependent pathway underlying craniofacial cartilage defects. Specifically, defective proteolytic processing of N-cadherin, a key adhesion molecule in chondrogenesis, is a central driver of pathology. We further uncover an unconventional trafficking mechanism in which ER stress and altered secretory …

Bap1: Genotype-Phenotype Correlation, Variant Classification, And Treatment Efficacy, Elizabeth Hobbs

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BRCA1-associated protein 1 (BAP1) is a tumor suppressor gene located on chromosome 3p21.3 and encodes a deubiquitinase enzyme (DUB) involved in DNA repair, cell cycle and metabolism, and apoptosis. BAP1 pathogenic germline variants are primarily associated with a familial cancer syndrome, Tumor Predisposition Syndrome 1 (TPDS1), but new missense variants have been linked to a neurodevelopmental disorder known as Kury-Isidor Syndrome (KURIS). Patients with TPDS1 variants have an increased risk for developing cancers, such as uveal and cutaneous melanomas, mesothelioma, and renal cell carcinoma, at an earlier age with lower thresholds for environmental exposures, mainly UV rays and asbestos, compared …

Behavior In Phelan-Mcdermid Syndrome: Clinical Characteristics, Genetic And Metabolic Contributions, And Evaluation Of Behavioral Assessment Tools, Emily Payne

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Phelan-McDermid syndrome (PMS) is characterized by genetic and phenotypic variability with varying levels of developmental delay, intellectual disability (ID), autism spectrum disorder (ASD), speech delay, minor dysmorphic features, and behavioral issues. Genetic causes of PMS involve deletions in the 22q13.3 region or pathogenic/likely pathogenic variants in SHANK3. Due to the significant heterogeneity and complexities seen in individuals with PMS, there are numerous challenges surrounding research, accurate diagnoses, assessments, and the creation of treatments. Behavioral issues are present in the majority of individuals with PMS, including lower levels of adaptive behavioral skills needed for daily functioning, disruptive behaviors, restricted and …

Drosophila Model Of Cocaine Use Disorder, Jeffrey Hatfield

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Cocaine use disorder (CUD) is a major public health challenge. While the primary mechanism of action of cocaine has been well characterized, and family studies have identified a strong genetic component, the specific genetic factors that influence susceptibility to development of CUD remain poorly understood. Genetic studies of cocaine use disorder are difficult in humans, but can be readily performed in Drosophila, where environment, genetic background, and cocaine exposure can be controlled. Drosophila exhibit behavioral and transcriptomic responses to cocaine, which binds to the dopamine transporter in fruit flies as it does in humans. Here, we use Drosophila to …

Genomic Data Science Approaches For Understanding Human Diseases, Snehal Shah

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The intricate interplay of genetic predisposition, environmental influences, and lifestyle acts as the multifactorial landscape of diseases. Understanding this complexity presents a significant challenge. Molecular insights into disease mechanisms, particularly the interactions of DNA, RNA, and proteins with environmental and lifestyle factors, have revolutionized disease diagnosis, prognosis, and treatment. High-throughput technologies, such as next-generation sequencing, generate large amounts of molecular data, holding a wealth of knowledge. These datasets unveil the roles of genes and their interactions with various factors through analysis, shedding light on previously unknown molecular mechanisms underlying disease pathogenesis. Furthermore, they facilitate the discovery of biomarkers crucial for …

A Systems Genetics Approach To Drosophila Melanogaster Models Of Rare And Common Neurodevelopmental Disorders, Rebecca Macpherson

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Fetal Alcohol Spectrum Disorders are a group of disorders resulting from prenatal alcohol exposure, presenting with neurodevelopmental and facial abnormalities of varying severity. SSRIDDs and CdLS are rare disorders of chromatin modification, resulting in patients with a wide range of craniofacial, digit and/or neurodevelopmental abnormalities. All of these disorders have a wide range of clinical phenotypes and disease severity, yet the role of potential genetic modifiers and gene-gene or gene-environment interactions in disease pathogenesis is largely unknown and cannot be studied in humans. Insufficient numbers of patients with a single rare disorder prevent investigation of genetic factors beyond the focal …

An Overview Of Risk Factors For Neural Tube Defects And An Investigation Within South Carolina, Lucy Pulliam

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Neural tube defects (NTDs) are congenital anomalies that affect both the morbidity and mortality of infants worldwide. Inadequate levels of the vitamin folate in women during early pregnancy have been shown to be a risk factor for NTDs. Recent efforts to ensure adequate folate intake in mothers have been helpful in reducing but not eliminating NTDs. This dissertation examines additional risk factors for NTDs as possible focus areas for decreasing NTD occurrence.

Chapter Two and Chapter Three are literature reviews conducted to explore select factors associated with an increased risk of NTDs and how these factors may affect folate availability …

Elucidating Acetate Metabolism: Identification Of Transporters And Enzymes Required For Acetate Utilization In The Fungal Pathogen Cryptococcus Neoformans, Perry L. Kezh

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Cryptococcus neoformans is the leading cause of fungal meningitis world-wide. While exposure to this environmental sporophyte is common during childhood, those who are immune compromised are at risk of infection. Following inhalation, this basidiomycetous fungus subsequently colonizes other organs though hematogenous dissemination, eventually crossing the blood brain barrier and colonizing the brain where it causes as cryptococcal meningitis. Changes in the availability of carbon sources stemming from the movement from soil to the lungs induce changes in fungal metabolism. Specifically, alveolar macrophages, which present a first line of defense against infection, provide a glucose-/amino acid-poor environment. As such, the use …

Assesment Of Structure, Function, And Microevolutionary Dynamics Of Extrachromosomal Circular Dna In Chinese Hamster Ovary Cells, Dylan Chitwood

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Chinese hamster ovary (CHO) cell lines are among the most popular expression hosts used in biopharmaceutical manufacturing due to relative ease of culture, capacity to perform human-like post-translational modifications, and non-susceptibility to viruses. However, the intrinsic plasticity of the CHO genome can lead to undesired genetic rearrangements, phenotypic shifts, reduced product quality, and early culture termination that prevents continuous biomanufacturing. A characteristic of plastic and unstable genomes that is poorly understood in CHO cells is extrachromosomal circular DNA (eccDNA). EccDNAs are focal amplifications of the genome that reside in the extranuclear space. These plasmid-like entities are structurally complex and are …

Acetate Metabolism In The Fungal Pathogen Cryptococcus Neoformans, Oly Ahmed

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Cryptococcus neoformans is an environmental basidiomycetous fungus with a worldwide distribution and a wide range of habitats. Inhalation of the desiccated yeasts or spores of C. neoformans often leads to opportunistic pulmonary infections in immunocompromised individuals, and in severe cases causes lethal meningitis following hematogenous dissemination. During infection, depending on the tissue and disease state, the invading fungi experience a range of nutrient microenvironments within the host body. As a result, rapid metabolic adaptations geared towards efficient utilization of carbon sources alternative to glucose become one of the prime determinants of survival and growth for the pathogen. Incidentally, cryptococcal infection …

Diagnosis Of Urinary Tract Infections And Rapid Molecular Characterization Of Antibiotic Resistance, Mohammed Harris

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Urinary tract infections (UTIs) are one of the most common infectious clinical entities in both community and hospital settings. They have a broad range of clinical severity yet inflict large epidemiological burden of morbidity and mortality on patients and the healthcare system with billions of dollars in cost of treatment. Understanding what methods are optimal for diagnosing UTIs are critical to mitigate the marked impact and cost of these infections.

Chapter 1 and 2 in this work surveys the broad array of diagnostic modalities for UTIs and highlights their advantages and limitations in the context of the current standard of …

Deciphering Medicago Truncatula Nodulation Using Time-Series Transcriptomic Data At Multiple Levels Of Resolution: Organ, Tissue, And Single-Cell, Yueyao Gao

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Use of chemical nitrogen fertilizers has environmental repercussions such as global warming, soil contamination, and aquatic eutrophication. Legumes form a symbiotic association with nitrogen-fixing bacteria (rhizobia sp.) to obtain atmospheric nitrogen through the formation of a specialized root structure called a nodule. Understanding the transcriptional reprogramming during nodulation is a powerful approach to decipher the genetic control of nodulation, with the goal of engineering nitrogen-fixing symbiosis into non-leguminous crops. This dissertation focuses on the analytics of bulk, tissue-specific, and single-cell RNA-seq technologies and how I utilized them to discover a collection of genes to aid in deciphering nodulation mechanisms in …

Heat Stress Response And Excystation In Entamoeba Histolytica, Irem Bastuzel

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Entamoeba histolytica is a water- and food-borne intestinal protozoan parasite that causes amoebiasis and liver abscess and is responsible for symptomatic disease in approximately 100 million people each year leading to ~ 100,000 deaths. The most common disease transmission follows the oral-fecal route, but it can also be transmitted by mechanical vectors such as animals carrying the amoeba from contaminated sources to water systems. In rare cases, disease transmission has been recorded in some patients in which men-to-men sexual practices were preferred.

The life cycle of E. histolytica starts through ingestion of infectious cysts, which are non-dividing, quadri-nucleated structures surrounded …

Genetics And Genomics Education Among Physician Assistants, Wesley Patterson

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This dissertation comprises five chapters to describe genetics and genomics education among physician assistant/associate (PA) students and practicing PAs. Chapter I introduces the gap in supply and demand of genetic services, the need for non-genetics healthcare providers to fill the gap, and the PA profession as a solution.

Chapter II is a rapid literature review that summarizes the available literature regarding genetics and genomics education for PAs. A paucity of literature exists to describe the current state of PA genetics-genomics education. The few studies retrieved describe content being taught in PA programs, the number of genetics-genomics contact hours PA students …

Characterization Of Mef2c-Related Disorders: Genotype, Phenotype, And Gene Pathway Dysregulation, Jessica Ann Cooley Coleman

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MEF2C­-related disorders are characterized by intellectual disability, developmental delay, lack of speech, seizures, stereotypic movements, hypotonia, and brain abnormalities and are caused by pathogenic alterations involving the MEF2C gene. Despite published cases, MEF2C­-related disorders are difficult to recognize clinically. These studies sought to further characterize MEF2C­-related disorders by investigating the genotypes, phenotypes, and gene functions (or dysfunctions) associated with the disorder.

Tremors have been reported in some patients with MEF2C­-related disorders, but the concept of tremors has been complicated by vague definitions and numerous categorization methods. We performed a concept analysis following the Walker and Avant …

Identification Of Genetic Factors Underlying Megaesophagus And Startle Disease In Dogs, Sarah M. Bell

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Dogs provide an excellent model for human hereditary disease research; thus, the development of canine genomic tools has been prioritized in recent years. Today, SNP arrays, multiple genome assemblies, and multi-breed reference panels containing whole genome resequencing (WGS) data from hundreds of canids are available to facilitate genome-wide genotyping in the dog. Herein, a variety of genome-wide techniques are employed to identify the genetic factors underlying congenital idiopathic megaesophagus (CIM) in two breeds, German shepherd dogs (GSDs) and Great Danes, and startle disease in Spanish greyhounds.

CIM is a complex canine esophageal motility disorder characterized by ineffective peristalsis and esophageal …

Identification Of Biomarker Systems Of Autism Spectrum Disorder And Uterine Cancer, Allison Hickman

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Complex diseases and disorders pose a challenge to scientists due to their variable and often inconsistent genetic and environmental underpinnings across affected individuals. Because of this variability, large condition-specific datasets and corresponding analytical tools and approaches are being curated as resources to investigate potential genetic trends in complex diseases and disorders. In this Dissertation, I used DNA- and RNA-based resources to discover polygenic biosignatures associated with Autism Spectrum Disorder (ASD) or uterine cancer. To explore the intersection of small-effect common DNA variants and regulation in ASD, I discovered and analyzed trends in allelic associations at eQTLs within ASD-affected individuals. Association …

Genetic And Mirna Transcriptomic Analysis Of Autoregulation Of Nodulation Signaling In Medicago Truncatula, Diptee Chauligain

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Legumes can source nitrogen from the air through biological nitrogen fixation inside root nodules formed in a symbiosis with rhizobia. A complex root-to-shoot-to-root signaling pathway called Autoregulation of Nodulation (AON) controls the number of nodules formed depending on the plant’s nitrogen requirements. In Medicago truncatula, the MtSUNN receptor complex in the shoot binds to the root-generated AON signals, peptides called MtCLEs, resulting in downregulation of miR2111 expression in the shoot, with the effect of decreased transport of miR2111 to the roots. Decreased miR2111 levels in the roots then cause an increase in transcript levels of the miR2111 targets MtTML1 …

Development Of New Bioinformatic Approaches For Human Genetic Studies, Jose Andres Guevara Coto

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The development of bioinformatics methods for human genetic studies utilizes the vast amount of data to generate new valuable information. Machine learning and statistical coupling analysis can be used in the study of human diseases. These diseases include intellectual disabilities (ID), prevalent in 1-3% of the population and caused primarily by genetics. Although many cases of ID are caused by mutations in protein-coding genes, the possible involvement of long non-coding RNAs (lncRNAs) in ID due to their role in gene expression regulation, has been explored. In this study, we used machine learning to develop a new expression-based model trained using …

Tackling Adverse Environment—Molecular Mechanism Of Plant Stress Response And Biotechnology Tool Development, Ning Yuan

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Abiotic and biotic stresses such as drought, salt, nutrition starvation, and pathogen infection are major factors threatening our agricultural production. With the rapidly increasing population and limited arable land area, genetic engineering of crops for new products with more stable and higher yield than conventional cultivars under adverse environment provides a powerful new tool for use in developing novel GMOs (Genetically Modified Organisms) to feed the large population in the immediate future. To develop novel GMOs with enhanced performance under adverse conditions, we need first to understand molecular mechanisms underlying plant stress response. To better understand how signaling transduction pathway …

Microrna-Mediated Plant Development And Response To Environmental Stress In Perennial Grasses, Shuangrong Yuan

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World population will pass nine billion by 2050, while the agricultural land area will not increase dramatically in the coming decades. To meet the ever-increasing food demand, genetically engineered crops have been rapidly adopted for crop productivity. MicroRNAs have become increasingly attractive as targets in crop genetic modification due to their regulatory role in fine-tuning many essential biological processes. My research explores the potentials of microRNA528 (miR528) and miR396 for use in genetic modifications of the important agronomic traits of plant development, abiotic stress response, and/or flowering time control in an economically and environmentally important perennial monocot species, creeping bentgrass …

Candidate Gene Studies In Patients With Autism Spectrum Disorder, Pamela Jackson

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Autism Spectrum Disorder is a grouping of disorders that range from the diagnosis of Asperger Syndrome to Autistic Disorder (formally known as autism). Attention Deficit Disorders and Pervasive Developmental Disorder-Not Otherwise Specified are also a part of this spectrum of disorders. Autism Spectrum Disorder affects one out of every 110 children and has a male to female ratio of 4:1. This has led to the need to identify genes that may be causative for this disorder.
Several genome-wide scans have been conducted and have identified locations in the human genome that may contain causative genes for Autism Spectrum Disorder. One …

The Population Genetics Of The Endangered Scalloped Hammerhead Shark, Sphyrna Lewini, Across Its Eastern Pacific Range, Holly Nance

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I have characterized the population genetic structure, inferred the evolutionary processes shaping it, and estimated effective population size (Ne) using different contemporary and coalescent methods in the endangered scalloped hammerhead shark, Sphyrna lewini, throughout its Eastern Pacific (EP) range. I found significant genetic differentiation among seven coastal sites between Mexico and Ecuador using 15 microsatellite loci, and significant isolation by distance among samples of mtDNA control region haplotypes. While Bayesian statistical analyses and coalescent-based methods revealed low levels of ecological connectivity between most sampled sites (point estimates of Nm = 0.6 - 7.3), mismatch analyses showed that all populations experienced …

Mapping Quantitative Trait Loci Associated With Chilling Requirement And Bloom Date In Peach, Shenghua Fan

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Chilling requirement (CR), together with heat requirement (HR), determines bloom date (BD), which impacts climatic distribution of genotypes of temperate tree species. The molecular basis of floral bud CR is poorly understood despite its importance to fruit tree adaptation and production. A peach F2 populations developed from two genotypes with contrasting CR values was used for QTL mapping for CR, HR and BD. Using the Contender × Fla.92-2c population, 20 QTLs with additive effects were identified for three traits including one major QTL for CR and two major QTLs for BD. Particularly, one genomic region of 2cM pleiotropic for the …