Genetics and Genomics Commons^™

Genotype Error Due To Low-Coverage Sequencing Induces Uncertainty In Polygenic Scoring, Ella Petter, Yi Ding, Kangcheng Hou, Arjun Bhattacharya, Alexander Gusev, Noah Zaitlen, Bogdan Pasaniuc

Faculty, Staff and Student Publications

Polygenic scores (PGSs) have emerged as a standard approach to predict phenotypes from genotype data in a wide array of applications from socio-genomics to personalized medicine. Traditional PGSs assume genotype data to be error-free, ignoring possible errors and uncertainties introduced from genotyping, sequencing, and/or imputation. In this work, we investigate the effects of genotyping error due to low coverage sequencing on PGS estimation. We leverage SNP array and low-coverage whole-genome sequencing data (lcWGS, median coverage 0.04×) of 802 individuals from the Dana-Farber PROFILE cohort to show that PGS error correlates with sequencing depth (p = 1.2 × 10

Beyond The Exome: What’S Next In Diagnostic Testing For Mendelian Conditions, Monica H Wojcik, Chloe M Reuter, Shruti Marwaha, Medhat Mahmoud, Michael H Duyzend, Hayk Barseghyan, Bo Yuan, Philip M Boone, Emily E Groopman, Emmanuèle C Délot, Deepti Jain, Alba Sanchis-Juan, Genomics Research To Elucidate The Genetics Of Rare Diseases (Gregor) Consortium, Lea M Starita, Michael Talkowski, Stephen B Montgomery, Michael J Bamshad, Jessica X Chong, Matthew T Wheeler, Seth I Berger, Anne O'Donnell-Luria, Fritz J Sedlazeck, Danny E Miller

Faculty, Staff and Student Publications

Despite advances in clinical genetic testing, including the introduction of exome sequencing (ES), more than 50% of individuals with a suspected Mendelian condition lack a precise molecular diagnosis. Clinical evaluation is increasingly undertaken by specialists outside of clinical genetics, often occurring in a tiered fashion and typically ending after ES. The current diagnostic rate reflects multiple factors, including technical limitations, incomplete understanding of variant pathogenicity, missing genotype-phenotype associations, complex gene-environment interactions, and reporting differences between clinical labs. Maintaining a clear understanding of the rapidly evolving landscape of diagnostic tests beyond ES, and their limitations, presents a challenge for non-genetics professionals. …

Sensing The Rhizosphere: Microbial Transcriptome Responses To Root Exudates And Redox-Active Metabolites, Ankita Bhattacharyya

Dissertations

The term “rhizosphere” describes the dynamic interface between plant roots and soil influenced by root exudates. It is a hotspot of microbial activity, plant-microbe, and microbe-microbe interactions. Distinct variations in bacterial diversity are thought to be driven by plant root exudates. However, the molecular details of these processes still remain unclear.

I addressed this gap by focusing on two strains, Pseudomonas synxantha 2-79 and Burkholderia lata 383, representing diverse groups of Gammaproteobacteria comprised of species with environmental, agricultural, and medical significance. In the first part of this project, we used a combination of metabolomics and RNA-seq to characterize transcriptome responses …

The Impact Of Soil Disturbance On Soil Bacterial Community Composition, Marie A. Rodriguez, Mark Peach, Timothy D. Trott

Research in Biology

Soil bacterial communities are an important part of terrestrial ecosystems due to their roles in biogeochemical cycling processes. Consequently, understanding how soil disturbance affects the soil bacterial diversity is vital to understanding the entire ecosystem. In this study we examined the effects of soil disturbance (by mining) on the soil bacterial community composition from three sites on Bauxite Ridge in Southeast Tennessee compared to three undisturbed sites in a nearby location. The soil bacterial community was analyzed by 16S rDNA amplicon sequencing of total DNA extracted from the soil samples collected from each of the six sites. Characterization of the …

Examining The Different Soil Horizons Of White Oak Mountain, Tn And Their Effect On The Soil Microbial Community, Ji Won Moon, Timothy D. Trott

Research in Biology

Soil microorganisms participate in the diverse interaction within virtually all ecosystems, consequently affecting the associated human and animal population. Identifying how edaphic variables alter the functional and taxonomic diversity of the soil microbial community requires an examination of total microbial soil diversity and abundance. This research study examined the effect of soil depth and horizon on the soil microbial community composition of White Oak Mountain. The soil microbial community was characterized by 16S/18S/ITS rDNA amplicon sequencing of the DNA extract of six samples from the three major soil types identified: HcE, MoE, and uMvC. OTU clustering analysis and both alpha …

A Phylogenetic Analysis Of The Leuctra Ferruginea (Walker 1852) Species Group (Plecoptera: Leuctridae), Madison Layer

Masters Theses & Specialist Projects

Leuctra Stephens, 1836 is a genus of Plecoptera (Leuctridae) distributed widely across the Northern Hemisphere, with approximately 210 species reported from eastern North America, Europe, northern Africa, and sporadically across Asia. Eastern North America harbors a small proportion of the global Leuctra fauna (ca. 15% = 31 species), most of which occur in the ancient Appalachian Mountains and unglaciated landscapes in the southeastern USA. Nearctic Leuctra species, except for L. moha and L. crossi, have been divided into five species groups based on external male morphological characteristics. Current phylogenies of Nearctic Leuctra are partial and preliminary, and no comprehensive …

Assessing The Effect Of Reservoirs On Gene Flow In The Southern Two-Lined Salamander (Eurycea Cirrigera), Anna Favalon

Masters Theses & Specialist Projects

Biodiversity is an essential component of natural environmental dynamics. Unfortunately, diversity is threatened by human activities and relies on conservation efforts. An important aspect of biodiversity conservation lies in protecting population connectivity and gene flow. In the mid-1900s, many Kentucky rivers were dammed, creating deep, lentic reservoirs in the valleys once occupied by dynamic, lotic rivers. For species inhabiting the rivers and associated tributaries, the central reservoirs may reduce connectivity among populations and impose a barrier to gene flow. The connectivity of populations on landscapes altered by the creation of reservoirs can be assessed by merging the principles of landscape …

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

All Dissertations

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 …

Perspectives On The Application Of Pharmacogenomics In Patient Care, Erika Meaddough

All Dissertations

Pharmacogenomics, the study of the genetic contribution to inter-individual differences in drug response, has great potential for realizing the goals of precision medicine: the right drug, for the right patient, at the right time. However, application in the clinical setting, through the use of pharmacogenetic testing, still has not gained widespread acceptance. This work describes multiple aspects of pharmacogenomics, which drive current research in this field.

Chapter I is an introduction to pharmacogenomics. Regulatory agencies and professional organizations across the globe provide information about gene-drug interactions that could lead to adverse drug reactions, and/or therapeutic failure. Risks for poor health …

Elucidating Mechanisms Of Rad51 Regulation During The Replication Stress Response, Alexandra Hawks

All Dissertations

The genome must be accurately and efficiently replicated each cell cycle to ensure there is not accumulation of mutations or structural rearrangements. When an active replication fork stalls, there are multiple DNA damage tolerance (DTT) pathways that can act to both protect integrity of DNA at the fork and restart replication. RAD51, a vital recombinase, works with HLTF, ZRANB3, and SMARCAL1 or FBH1 to regress stalled replication forks. RAD51 is loaded and stabilized onto the replication fork to protect the newly synthesized DNA from degradation. RAD51 is also active during the template switching DDT pathway. This pathway can be utilized …

Investigation Of Orthohantavirus Genetics In Rodent Reservoirs And Clinical Samples, Samuel Melvin Goodfellow

Biomedical Sciences ETDs

Orthohantaviruses are negative-sense, single stranded RNA viruses with trisegmented genomes that can cause severe disease in humans and are carried by several host reservoirs throughout the world. In the United States, Sin Nombre orthohantavirus (SNV) is the primary cause of hantavirus cardiopulmonary syndrome (HCPS) with a fatality rate of ~36% and the highest cases occuring in the southwest region. The primary SNV host reservoir is thought to be the western deer mouse, Peromyscus maniculatus, however it has been shown that other rodents can carry different orthohantaviruses. We designed a pan-orthohantavirus detection tool to survey several small mammal populations throughout New …

Anything But Bland: Uncovering The Hidden Diversity And Genomic Origin Of The Threatened Vanilla Spice, Paige Ellestad

Boise State University Theses and Dissertations

Conserving the genetic diversity of crop species and their wild relatives has become a mounting concern as the detrimental effects of climate change, habitat destruction, and genetic erosion are being realized. In this epoch of unprecedented biodiversity loss, the genetic resources needed to improve crops may be at risk of extinction. Even one of the most iconic spices, vanilla, is threatened. Wild populations of the main vanilla producing species, Vanilla planifolia Andrews (Orchidaceae), are being rapidly extirpated due to deforestation and illegal harvesting in their native range. On top of that, clonal propagation methods within cultivated plants are hypothesized to …

Sequestered Sequences: A Bioinformatic Approach To The Forgotten Genome, Dylan Barth

UNLV Theses, Dissertations, Professional Papers, and Capstones

As high throughput sequencing generates ever increasing amounts of genetic and epigenetic data new lines of inquiry open up in the field of genomic research. In this thesis, we discuss three ways in which we can utilize public databases of next generation genomic data in order to study areas of the genome previously ignored by traditional approaches. These include the study of linker regions between domains of proteins, indirect enhancers that do not strongly contact promoters of genes they regulate, and transposon-derived enhancer elements. The work uncovers many exceptions to known biological principles, and adds nuance to our understanding of …

The Genetic Relationship Between Peripheral Inflammation And Alzheimer’S Disease, Davis Cammann

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s disease (AD) is the leading cause of dementia worldwide, and has become an ever-present problem in aging populations. An increasing body of evidence suggests that neuroinflammation is one of the key drivers of AD pathology. One overlooked contributor to this burden is peripheral inflammation throughout the body. Due to increased permeability of the blood-brain-barrier (BBB) in older age, inflammatory plasma proteins and immune cells infiltrate the CNS and drive neuroinflammation through interactions with neurons and glia. In addition, age-related changes in the composition of gut microbiome taxa lead to increased gut permeability and inflammatory burden. Because inflammatory factors are …

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

All Dissertations

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 …

Characterization Of The Immunoglobulin Lambda Chain Across Diverse Human Populations., William Gibson

Electronic Theses and Dissertations

The adaptive immune system relies on a diverse set of over one hundred immunoglobulin (IG) genes across three genomic loci that are variably combined to form antibodies (Ab). The IG Lambda locus is one of two loci which encodes the IG light chain. The complexity of the IGL locus severely limits the effective use of standard short-read sequencing, limiting our knowledge of population diversity in these loci. We leveraged single molecule real-time (SMRT) long-read sequencing in conjunction with IGL-targeted DNA capture to develop the method IG-Cap for accurate and high-throughput sequencing of the IGL locus. We benchmarked this method using …

Identifying Functional Enhancers For Fibrotic Gene Regulation In Liver Fibrosis, Parnaz Merikhian

Dissertations and Theses (Open Access)

Liver fibrosis is characterized by progressive activation of proliferating and migrating myofibroblasts that lead to accumulation of extracellular matrix (ECM). These myofibroblasts most arise from activated liver-resident hepatic stellate cells (HSCs). There is an increasing number of patients suffering from liver fibrosis in developed countries including the United States, which is anticipated to continue to grow during 2023-2033 period. TGF-β1 is a key cytokine with a significant role in regulating cell differentiation and adhesion in liver fibrosis. TGF-β signaling triggers gene expression changes in HSCs, including that of fibrotic and EMT-related genes, which then functionally promote HSCs activation and fibrogenesis. …

Co-Targeting Nucleus Accumbens Associate 1 And Nf-Κb Signaling Synergistically Inhibits Melanoma Growth, Lixiang Gu, Xingcong Ren, Chrispus Ngule, Xiaofang Xiong, Jianxun Song, Zhiguo Li, Jin-Ming Yang

Markey Cancer Center Faculty Publications

Nucleus-accumbens-associated protein-1 (NAC1) is a cancer-related transcriptional factor encoded by the NACC1 gene, which is amplified and overexpressed in various human cancers and has been appreciated as one of the top potential cancer driver genes. NAC1 has therefore been explored as a potential therapeutic target for managing malignant tumors. Here, we show that NAC1 is a negative regulator of NF-κB signaling, and NAC1 depletion enhances the level of the nuclear NF-κB in human melanoma. Furthermore, the inhibition of NF-κB signaling significantly potentiates the antineoplastic activity of the NAC1 inhibition in both the cultured melanoma cells and xenograft tumors. This study …

Metabolic Disruption Induced By Mtor Signaling Pathway Inhibition In Regulatory T-Cell Expansion For Clinical Application, Roberto Gedaly, Gabriel Orozco, Alexandre P. Ancheta, Mackenzie Donoho, Siddharth Desai, Fanny Chapelin, Aman Khurana, Lillie J. Lewis, Cuiping Zhang, Francesc Marti

Markey Cancer Center Faculty Publications

Background: Regulatory T cell (Treg) therapy is considered an alternative approach to induce tolerance in transplantation. If successful, this therapy may have implications on immunosuppression minimization/withdrawal to reduce drug-induced toxicity in patients. The aim of this study was to assess the efficacy of the mTORC1/C2 inhibitor, AZD8055, in the manufacturing of clinically competent Treg cells and compare the effects with those induced by rapamycin (RAPA), another mTOR inhibitor commonly used in Treg expansion protocols.

Methods: Primary human Treg cells were isolated from leukapheresis product. Cell viability, expansion rates, suppressive function, autophagy, mitochondrial unfolded protein response (mitoUPR), and cell metabolic profile …

The S1p Receptor 1 Antagonist Ponesimod Reduces Tlr4-Induced Neuroinflammation And Increases Aβ Clearance In 5xfad Mice, Zhihui Zhu, Liping Zhang, Ahmed Elsherbini, Simone M. Crivelli, Priyanka Tripathi, Carmen Harper, Zainuddin Quadri, Stefka D. Spassieva, Erhard Bieberich

Markey Cancer Center Faculty Publications

Background Previously, we showed that the sphingosine-1-phosphate (S1P) transporter spinster 2 (Spns2) mediates activation of microglia in response to amyloid β peptide (Aβ). Here, we investigated if Ponesimod, a functional S1P receptor 1 (S1PR1) antagonist, prevents Aβ-induced activation of glial cells and Alzheimer’s disease (AD) pathology.

Methods We used primary cultures of glial cells and the 5XFAD mouse model to determine the effect of Aβ and Ponesimod on glial activation, Aβ phagocytosis, cytokine levels and pro-inflammatory signaling pathways, AD pathology, and cognitive performance.

Findings Aβ42 increased the levels of TLR4 and S1PR1, leading to their complex formation. Ponesimod prevented the …

Utilizing Crispr Cas9 To Visualize Dopamine Receptors In Caenorhabditis Elegans, Lauren Michelle Velasquez

Electronic Theses, Projects, and Dissertations

Dopamine (DA) is a neurotransmitter with imperative implications in many functions including movement, reward, and cognition. Studying the pathways of dopaminergic neurons at multiple levels allows us to understand the ways in which these systems can go wrong. We study dopamine in a model system such as the worm Caenorhabditis elegans because of its relatively simple and well-characterized nervous system. DA is involved in regulating chemosensory behaviors in worms. The purpose of this research project is to definitively answer the following question: Are the dopamine receptors DOP-1 and DOP-4 expressed in chemosensory neurons? Previous reporter assays show that neither of …

Genetic Parameters For Heat And Salinity Stress Tolerance In Northern Gulf Of Mexico Eastern Oyster, Crassostrea Virginica, Paul Mcdonald

Master's Theses

Summer mortalities in Gulf of Mexico eastern oysters have been linked to excessively high temperatures, and chronic exposure to low salinity. In this study, the feasibility of improving tolerance to these two stresses by selection was evaluated in common garden experiments employing a pool of 160 families. Heat stress tolerance was evaluated in seed (3.5 months) and adults (14 months) by applying a sustained temperature of 38-39 °C until all oysters expired. Low salinity challenges on juveniles (9 months) and adults (15 months) applied a salinity of 2.5 psu. Survival duration of individual oysters during challenges was recorded and tissue …

Assessing The General Public's View Of Direct-To-Consumer (Dtc) Genetic Testing And Their Interpretation Of Dtc Website Disclaimer Messages., Madison Ruehl, Shelly Hovick, Alisdair Philp, Kevin Sweet

Medical Education Articles

The general public continues to show increased interest and uptake of Direct-to-Consumer (DTC) genetic testing. We conducted an online survey (N = 405) to assess genetics knowledge, interest, and outcome expectancy of DTC genetic testing before and after exposure to a sample DTC disclaimer message. Descriptive statistics were used to analyze the relationship between previous genetic knowledge, attitudes and self-reported systematic processing of a sample DTC disclaimer message, outcome expectancies, and interest to pursue DTC genetic testing. Increased genetic knowledge and more positive attitudes towards DTC genetic testing were associated with increased self-reported systematic processing of the DTC disclaimer message. …

T-Cell Receptor Beta Variable Gene Polymorphism Predicts Immune-Related Adverse Events During Checkpoint Blockade Immunotherapy, Bettzy Stephen, Joud Hajjar, Shrutii Sarda, Dzifa Yawa Duose, Jeffrey M Conroy, Carl Morrison, Anas Alshawa, Mingxuan Xu, Abdulrazzak Zarifa, Sapna P Patel, Ying Yuan, Evan Kwiatkowski, Linghua Wang, Jordi Rodon Ahnert, Siqing Fu, Funda Meric-Bernstam, Geoffrey M Lowman, Timothy Looney, Aung Naing

Faculty, Staff and Student Publications

BACKGROUND: Immune checkpoint inhibitors have revolutionized cancer treatment. However, they are associated with a unique spectrum of side effects, called immune-related adverse events (irAEs), which can cause significant morbidity and quickly progress to severe or life-threatening events if not treated promptly. Identifying predictive biomarkers for irAEs before immunotherapy initiation is therefore a critical area of research. Polymorphisms within the T-cell receptor beta (TCRB) variable (TRBV) gene have been implicated in autoimmune disease and may be mechanistically linked to irAEs. However, the repetitive nature of the TCRB locus and incomplete genome assembly has hampered the evaluation of TRBV polymorphisms in the …

Genetic Analysis Of Crossover Defective Mouse Spermatocytes Reveals Discrete Crossover Precursor Intermediates, Tolkappiyan Prem Kumar

Dissertations and Theses (Open Access)

In healthy, non-replicating somatic cells of diploid organisms, like humans and mice, there are two copies of each chromosome, one from each parent. However, the germ cells of these organisms, the oocytes, and the sperm, have only one copy of each chromosome, thus ensuring that when haploid oocytes and sperm fuse to form a zygote, a diploid number of chromosomes is restored. The reduction of a diploid number of chromosomes to a haploid number of chromosomes takes place during meiosis. The meiotic cell cycle consists of two rounds of cell division, Meiosis I and Meiosis II. Meiosis I create haploid …

Landscape Of Ecdna-Borne Non-Coding Rnas In Glioblastoma, Dexin Yang

Dissertations and Theses (Open Access)

Recent advances in cancer genetics found that strong oncogene transcription can occur on a form of non-chromosome DNAs that is often amplified to tens or hundreds of copies, and that can exist in more than half of cancer types. This type of genetic material was termed extrachromosomal DNA (ecDNA). ecDNA appears to be epigenetically highly accessible and transcriptionally active compared with chromosomal DNA, which may partially underlie their critical roles in driving oncogene overexpression and cancer evolution. However, the full molecular mechanisms and regulators that confer the exceptional transcriptional activity of ecDNA-associated genes are incompletely understood.

Enhancers are key genetic …

Molecular Mechanisms Behind Sars-Cov-2 Induced Host Genome Restructuring, Erin Simpson

Dissertations and Theses (Open Access)

Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2) has caused unprecedented morbidity and mortality worldwide. There are two pathophysiological hallmarks associated with severe patient outcomes after SARS-CoV-2 acute infection, namely delayed/weakened interferon production and overactive inflammatory responses. Our previous work has shown that these altered immune responses are due, at least in part, to significant alterations in 3D genome organization and epigenetic landscape following SARS-CoV-2 infection that are distinct from and more severe than changes caused by other viral infections or immune stimulants. While these changes at the chromatin level are important for understanding the immune dysregulation seen in some cases …

An Interdisciplinary Approach To Online Genetics Education, Pinar Ozmizrak

All Dissertations

This dissertation presents an interdisciplinary approach to online genetics education.

Chapter I provides an overview of remote education and a brief history of genetics. While the COVID-19 pandemic prompted a turn to emergency online education, exposure to this form of delivery has led to increased intentional online education.

Chapter II focuses on computer and technology use in healthcare by nursing students. This study investigated nursing students’ perspectives using a modified version of the Pretest for Attitudes Toward Computers in Healthcare (PATCH) assessment scale to explore students’ ideas about computers and technology in healthcare delivery. According to the PATCH scale, the …

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

All Dissertations

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 …

Met Alterations In Glioblastoma: Characterization Of Patient-Derived Xenografts And Therapeutic Strategies, Anna Musket

Electronic Theses and Dissertations

Glioblastoma is the most commonly diagnosed central nervous system primary malignancy and it is considered a terminal diagnosis with few treatment options available. Glioblastoma tumors frequently develop treatment resistance due in part to their highly heterogenic nature. The heterogeneity of glioblastoma is partially attributed to the presence of glioma stem-like cells (GSC), which are highly invasive and resistant to chemotherapy and irradiation treatments. Signaling of the receptor tyrosine kinase MET is a known regulator of GSC. Glioblastoma patients have an increasingly poor prognosis that corresponds with increasing MET expression. Both GSC and MET are known to contribute to treatment resistance …