Biology Commons^™

Association Of Structural Variation (Sv) With Cardiometabolic Traits In Finns, Lei Chen

Arts & Sciences Graduate Student Theses and Dissertations

Cardiovascular diseases (CVDs) are known to be associated with a variety of quantitative risk factors such as cholesterol, metabolites, and insulin. Understanding the genetic basis of these quantitative traits can shed light on the etiology, prevention, diagnosis, and treatment of disease. However most prior trait-mapping studies have focused on single nucleotide variants (SNVs) and Indels, with the contribution of structural variation (SV) remaining unknown. In this thesis, we present the results of a study examining genetic association between SVs and cardiometabolic traits in the Finnish population. In the first chapter, we used sensitive methods to identify and genotype 129,166 high-confidence …

Role Of 4r Tau In Astrocyte-Mediated Neuronal Toxicity And The Progression Of Neurodegenerative Disease, Lubov Alexandra Ezerskiy

Arts & Sciences Graduate Student Theses and Dissertations

The microtubule-binding protein tau is associated with neurodegenerative diseases, including Alzheimer’s disease, progressive supranuclear palsy, and a subset of frontotemporal dementias. In these tauopathies, tau becomes hyperphosphorylated and forms intracellular neurofibrillary tau tangles, contributing to synaptic dysfunction, neuronal death, and severe astrogliosis. Tau can be classified as having a 3-repeat (3R) or 4-repeat (4R) structure, resulting from alternative splicing of exon 10 within the MAPT gene. While the higher deposition of 4R tau characterizes many primary tauopathies, the role of 4R tau in neurodegenerative disease pathogenesis remains unclear. To investigate the role of tau isoforms in disease, we created tau …

Investigation Of Ifnγ-Induced Control Of Intracellular Pathogens, Michael Mcallaster

Arts & Sciences Graduate Student Theses and Dissertations

Genes required for the lysosomal degradation pathway of autophagy play key roles in topologically distinct cellular processes with significant physiologic importance. One of the first-described of these ATG gene-dependent processes is the requirement for a subset of ATG genes in interferon-γ (IFNγ)-induced inhibition of norovirus and Toxoplasma gondii replication. In this dissertation we identified novel components that are required for or that negatively regulate this immune mechanism. Enzymes involved in the conjugation of UFM1 to target proteins including UFC1 and UBA5, negatively regulated IFNγ-induced inhibition of norovirus replication via effects of Ern1. We identified and confirmed that IFNγ-induced inhibition of …

Vestibulospinal Circuit In The Larval Zebrafish, Zhikai Liu

Arts & Sciences Graduate Student Theses and Dissertations

The vestibular system sense gravity and self-motion to help animals maintain body balance. Although vestibular signals inform the brain of the directions and speed of our body movements, it still remains unclear how these sensory information are processed and organized in the central nervous system. My thesis aims to illustrate neural computation underlying central vestibular tuning and the topographic organization of the vestibular circuits. First I established a novel approach to perform whole-cell recording of synaptic inputs in vivo during multi-axis movements in the central vestibular neurons. This technical advance allowed me to simultaneously measure presynaptic and postsynaptic tuning, along …

Exploring Β-Cell Function And Heterogeneity In Obese Sm/J Mice, Mario Alejandro Miranda

Arts & Sciences Graduate Student Theses and Dissertations

Pancreatic β-cells perform glucose-stimulated insulin secretion, a process required to maintain systemic glucose homeostasis. Obesity promotes glycemic and inflammatory stress, causing β-cell death and dysfunction, resulting in diabetes. Efforts to improve β-cell function in obesity have been hampered by observations that β-cells are highly heterogeneous, varying in morphology, function, and gene expression. There is great need to understand the breadth of β-cell heterogeneity in health and obesity to improve diabetic therapies.High fat-fed SM/J mice spontaneously transition from hyperglycemic-obese to normoglycemic-obese with age, providing a unique opportunity to study β-cell adaptation. Here, we show that as they resolve hyperglycemia, obese SM/J …

Metabolic Control And Immune Barriers Of Hematopoietic Stem Cells, Hannah Pizzato

Arts & Sciences Graduate Student Theses and Dissertations

Hematopoietic stem cells (HSCs) have the unique ability to self-renew for life, to differentiate into mature blood lineages, and to readily engraft upon intravenous transplantation. As such, they are the only types of stem cells in routine clinical use. Understanding HSCs and hematopoietic development can provide many lessons for other types of stem cells as they near clinical utility. Through bone marrow transplantation, it was discovered that cells exist with regenerative potential. This led to the search to purify these cells and to determine the function of other hematopoietic cells. By isolating and transplanting cells expressing different combinations of surface …

The Evolving Mammalian 3d Epigenome, Mayank Choudhary Nishikant Choudhary

Arts & Sciences Graduate Student Theses and Dissertations

One of life’s greatest mysteries is how a 6ft long-strand of DNA (our genome) fits inside the nucleus of a cell that’s less than a tenth of the width of a strand of hair. Adding to that, this genome has functioned faithfully with high fidelity over hundreds of millions of years of evolution is simply mind boggling. Moreover, within our genomes, we find millions of copies of strange genetic hitchhikers that were once thought to be purely self-seeking and parasitic. Critical advances in technology, assay development, sequencing, and computation have brought us today at an opportune moment in space and …

Investigating The Role Of Bladder Epithelial Stem Cells In Bladder Mucosal Remodeling And Defense Against Infection, Seongmi Kim Russell

Arts & Sciences Graduate Student Theses and Dissertations

Urinary tract infections (UTIs) can be highly recurrent, and the mechanism(s) governing recurrence susceptibility are mostly unknown. Here I demonstrate bladder epithelial (urothelial)-intrinsic trained immunity as part of a differential mucosal remodeling response to an initial UTI. I established urothelial stem cell (USC) lines from isogenic mice with different UTI histories (naïve, chronic, or self-resolving) and discovered 2880 differential genome-accessible regions, indicating differential epigenetic reprogramming dependent on infection history. Differentiation of USC lines in vitro resulted in polarized urothelial cultures that recapitulated distinct remodeling morphologies seen in vivo and exhibited altered gene expression, including genes involved in cell death pathways. …

Regulation Of Host-Microbe Interactions In Autoimmunity And Antiviral Immunity By Cytosolic Nucleic Acid Sensing And Interferon Signaling, Derek Jerome Platt

Arts & Sciences Graduate Student Theses and Dissertations

Cytosolic nucleic acid sensing and interferon (IFN) signaling are central to the host immune response to microbial pathogens. However, dysregulation of immunological pathways such as these can result in devastating autoimmune disease. In order to provide a robust immune response to pathogen without causing harm to self, the host immune system must engage in a delicate balancing act, interacting with microbes and determining whether they are commensal or pathogenic. The cGAS-STING pathway is a key regulator of host-microbe interactions by cytosolic nucleic sensing and IFN signaling. Loss of function in the cGAS-STING pathway leads to increased susceptibility to pathogenic threats, …

Discovery Of Sex Differences In Response To P53 Loss And Gain-Of-Function In Glioblastoma, Nathan Cuyle Rockwell

Arts & Sciences Graduate Student Theses and Dissertations

The tumor suppressor TP53 (p53) is the most frequently mutated gene in cancer and among the most mutated genes in brain cancer. Functionally, p53 is a transcription factor that, when activated by an array of stress stimuli, regulates a complex transcriptional program that contributes to a variety of antiproliferative pathways. The loss of p53 function (LOF), either through mutation, deletion, or inhibition by alterations in the proteins that regulate p53, removes an essential barrier to the unfettered proliferation and genomic instability that drive transformation. Unlike most tumor suppressors, many p53 mutations are missense mutations that lead to stable expression of …

The Origins & Functional Effects Of Postzygotic Mutations Throughout The Human Lifespan, Nicole Briana Rockweiler

Arts & Sciences Graduate Student Theses and Dissertations

Mosaicism is pervasive in humans and yet we understand little of its causes and functional consequences across the lifespan. To help solve these mysteries, we developed a suite of tools, called Lachesis, to analyze postzygotic mutations (PZMs). LachesisDetect is a novel and accurate method to detect PZMs with VAFs as low as 0.04% from bulk RNA-seq samples. LachesisMap is an innovative supervised method to reconstruct postzygotic mutation phylogenies from putative prenatal PZMs. We applied Lachesis to 17,382 samples derived from 948 donors across 54 diverse tissues and cell types from the NIH’s Genotype-Tissue Expression (GTEx) project to produce the most …

Uncovering A Myc-Driven Tumor-Suppressive Program In Proliferating Lymphocytes, Elena Tonc

Arts & Sciences Graduate Student Theses and Dissertations

Rapid cell proliferation is a hallmark feature of adaptive immune cells lymphocytes. It is essential for the establishment of diverse antigen receptor repertoires and amplification of antigen-specific immune responses. While such proliferation is beneficial for host protection from infections and cancers, it inevitably elevates the risk of oncogenic transformation. In developing and germinal center B lymphocytes, the risk is further increased by endogenous, genomic insults due to antigen receptor rearrangements and somatic mutations, with which expression of the proto-oncogene c-MYC is closely associated. Nonetheless, frequencies of cancers originated from B lymphocytes are relatively low, suggesting that they are protected from …

Investigating The Differentiation And Functional Maturation Of Stem Cell-Derived Β Cells, Leonardo Velazco-Cruz

Arts & Sciences Graduate Student Theses and Dissertations

Diabetes mellitus is a chronic and global disease rapidly growing in prevalence. Diabetes can be characterized by the dysfunction or death of the glucose sensing insulin secreting  cell.  cells are located within the islet of Langerhans (islet), a tissue within the pancreas. Human islets are critical for the study and treatment of diabetes. However, they can only be obtained from cadaveric organ donors. These cadaveric islets do not proliferate and can only be maintained in vitro for short periods of time, making their availability rare and fleeting. Stem cell-derived -like cells can be generated in indefinite amounts and …

Peripheral Nerve Macrophages And Their Implications In Neuroimmunity, Peter Leon Wang

Arts & Sciences Graduate Student Theses and Dissertations

Macrophages are innate immune cells that protect against pathogens and maintain tissue integrity. In vertebrates, macrophages reside in every tissue where they perform specific functions from early development through adulthood. While macrophages provide important functions across all tissues, a major focus in recent years has been the role of resident brain macrophages, known as microglia, in neurodegeneration. As microglia have been shown to affect brain development, homeostasis, and disease, they demonstrate how immune cells critically mediate neurological health and point to the broader significance of neuroimmune interactions, or the coordinated actions of the nervous and immune systems for maintaining tissue …

Disentangling Glial Diversity In Peripheral Nerves At Single Nuclei Resolution, Aldrin Kay Yuen Yim

Arts & Sciences Graduate Student Theses and Dissertations

The ability to discern gene expression at single cell level is revolutionizing our understanding of both basic biology and human health. Peripheral nerves are essential communicators between the outside world and the CNS, as evidenced by the devastating effects of diseases that disrupt them, such as ALS, Charcot-Marie-Tooth Syndrome and diabetic neuropathy. Understanding peripheral nerve dysfunction at a mechanistic level is of considerable interest due to the increasing prevalence and associated patient care costs of these disorders. Although most research of the peripheral nerve has focused on glial-axonal interactions, the important contributions of other cell types besides Schwann cells, such …

Type I Interferon Regulation Of Chikungunya Virus Pathogenesis, Marissa Christine Locke

Arts & Sciences Graduate Student Theses and Dissertations

Chikungunya virus (CHIKV) is an arthritogenic alphavirus that acutely causes fever as well as severe joint and muscle pain. Chronic musculoskeletal pain persists in a substantial fraction of patients for months to years after the initial infection, yet we still have a poor understanding of the mechanisms responsible for chronic disease. While replicating virus has not been detected in joint-associated tissues of patients with persistent arthritis nor in various animal models at convalescent time points, viral RNA is detected months after acute infection. However, there has been a lack of tools to study the mechanisms of chronic CHIKV disease. To …

Linking Neuronal Protein Phosphatase 2a To The Dlk Stress Kinase Signaling Cascade, Margaret Hayne

Arts & Sciences Graduate Student Theses and Dissertations

Neurons are constantly responding to internal and external cues as they adapt through signaling cascades and transcriptional programs. I have identified a role for the dual leucine zipper kinase (DLK) and the transcriptional program it controls in neuronal inhibition of the protein phosphatase PP2A. PP2A is an essential phosphatase, expressed in all cell types and required for survival. There is a reduction in PP2A activity in Alzheimer’s disease patient brains which is linked to increased phosphorylation of the microtubule associated protein Tau and ultimately cell death. Here, I have demonstrated that PP2A acts to restrain the DLK stress response and …

Dendritic Processing And Efficient Coding In The Retina, Jen-Chun Hsiang

Arts & Sciences Graduate Student Theses and Dissertations

In early sensory systems, a copious amount of information needs to be simultaneously processed to extract salient stimulus features and compress representations for efficient transmission. My thesis addresses how the retina processes visual information to detect specific motion patterns and efficiently encode our environment for perception. Around 40 retinal ganglion cell (RGC) types in mammals send specific feature representations through their axons from the retina to the brain. RGCs are the sole source of visual information to the brain. Recent studies suggest that amacrine cells (ACs) generate feature-selective responses of RGCs, but little is known about their neuronal computations. We …

Computational Approaches For Screening Drugs For Bioactivation, Reactive Metabolite Formation, And Toxicity, Noah Flynn

Arts & Sciences Graduate Student Theses and Dissertations

Cytochrome P450 enzymes aid in the elimination of a preponderance of small molecule drugs, but can generate reactive metabolites that may adversely conjugate to protein and DNA, in a process known as bioactivation, and prompt adverse reaction, drug candidate attrition, or market withdrawal. Experimental assays are low-throughput and expensive to perform, so they are often reserved until later stages of the drug development pipeline when the drug candidate pools are already significantly narrowed. Reactive metabolites also elude in vivo detection, as they are transitory and generally do not circulate. In contrast, computational methods are high-throughput and cheap to screen millions …

Method Development For Enhancing Sensitivity Of Dynamic Nuclear Polarization Nuclear Magnetic Resonance Spectroscopy For Structural Studies Of Pkc-Drug Interactions, Patrick Terrence Judge

Arts & Sciences Graduate Student Theses and Dissertations

To perform the most relevant structural studies on biological systems, experiments need to be carried out when the target proteins are in their endogenous cellular environment. Nuclear magnetic resonance (NMR) is well-suited to probe the structure and dynamics of a wide variety of systems, including biologically relevant proteins. However, NMR suffers from an inherent lack of sensitivity. Dynamic nuclear polarization (DNP) NMR is a powerful technique that is used to enhance NMR sensitivity by transferring the greater polarization of exogenously doped electron spins to nuclear spins of interest though the use of a high-power microwave source. Solid effect radicals offer …

C. Elegans Response To Cadmium Toxicity, Brian James Earley

Arts & Sciences Graduate Student Theses and Dissertations

Cadmium is an environmental pollutant and significant health hazard that is similar to the physiological metal zinc. Residing in the same group of the periodic table, cadmium and zinc share chemical characteristics that are important for their industrial uses in electroplating, batteries, pigments, and metal alloys. The similarities of ionic cadmium and zinc have significant repercussions on biological systems. While it has long been clear that cadmium is toxic to biological systems, the mechanisms of cadmium toxicity remain poorly understood. In contrast, mechanisms of zinc homeostasis have been elucidated in growing detail. In C. elegans high zinc homeostasis is regulated …

Regulation Of Transcription Factor Binding Specificity: From Binding Motifs To Local Dna Context, Jiayue Liu

Arts & Sciences Graduate Student Theses and Dissertations

Regulation of transcription factor (TF) binding specificity lies at the heart of transcriptional control which governs how cells divide, differentiate, and respond to their environments. TFs are known to bind to DNA in a sequence specific manner, and such short sequence is known as transcription factor binding site (TFBS). However, the in vivo TF bound regions do not always contain a TFBS, and additionally, there are often excessive non-functional TFBSs with binding potential in the regulatory regions that are unbound for a given TF. This dissertation focuses on understanding the principles of TF binding specificity and is divided into two …

The Role Of Excited States In Determining Β-Lactamase Function And Bacterial Fitness, Catherine Rae Knoverek

Arts & Sciences Graduate Student Theses and Dissertations

Proteins are macromolecular machines that play a role in nearly every biological process. They are dynamic molecules which adopt many different conformations as they fold into their 3D structures, interact with their binding partners, and perform their functions. The most probable (lowest energy) protein conformation is referred to as the ground state, and this is often assumed to be the state determined by experimental methods such as x-ray crystallography. However, proteins also adopt higher energy excited states which can have significant probabilities. As these excited states are notoriously difficult to find and study, it is unclear if excited states contribute …

Comparative Analysis Of Longevity And Stress Resiliency Benefits Of Supplementation With High-Antioxidative Capacity Juices In Organisms That Are Representative Of Humans, Meghan Long

Honors Scholar Theses

Neurodegenerative disease presents itself in a complex array of illnesses that is increasingly affecting the geriatric population. There has not been research on a common cause since there are a culmination of reasons that are probable ranging from genetic to environmental factors. Antioxidants have been known to prevent and protect against the damage that is otherwise caused by reactive oxygen species (ROS). Thus, high-capacity antioxidant juices supplemented into the diet of animal models such as Caenorhabditis elegans, Drosophila melanogaster, rats, and humans will allow for the study of the possible benefits.

Although a conclusion and common causation on the usage …

Neutrophil Myeloperoxidase Derived Chlorolipid Production During Bacteria Exposure, Kaushalya Amunugama, Grant R. Kolar, David A. Ford

Biological Sciences Faculty Research & Creative Works

Neutrophils are the most abundant white blood cells recruited to the sites of infection and inflammation. During neutrophil activation, myeloperoxidase (MPO) is released and converts hydrogen peroxide to hypochlorous acid (HOCl). HOCl reacts with plasmalogen phospholipids to liberate 2-chlorofatty aldehyde (2-ClFALD), which is metabolized to 2-chlorofatty acid (2-ClFA). 2-ClFA and 2-ClFALD are linked with inflammatory diseases and induce endothelial dysfunction, neutrophil extracellular trap formation (NETosis) and neutrophil chemotaxis. Here we examine the neutrophil-derived chlorolipid production in the presence of pathogenic E. coli strain CFT073 and non-pathogenic E. coli strain JM109. Neutrophils cocultured with CFT073 E. coli strain and JM109 E. …

Neutrophil Myeloperoxidase Derived Chlorolipid Production During Bacteria Exposure, Kaushalya Amunugama, Grant R. Kolar, David A. Ford

Biological Sciences Faculty Research & Creative Works

Neutrophils are the most abundant white blood cells recruited to the sites of infection and inflammation. During neutrophil activation, myeloperoxidase (MPO) is released and converts hydrogen peroxide to hypochlorous acid (HOCl). HOCl reacts with plasmalogen phospholipids to liberate 2-chlorofatty aldehyde (2-ClFALD), which is metabolized to 2-chlorofatty acid (2-ClFA). 2-ClFA and 2-ClFALD are linked with inflammatory diseases and induce endothelial dysfunction, neutrophil extracellular trap formation (NETosis) and neutrophil chemotaxis. Here we examine the neutrophil-derived chlorolipid production in the presence of pathogenic E. coli strain CFT073 and non-pathogenic E. coli strain JM109. Neutrophils cocultured with CFT073 E. coli strain and JM109 E. …

Pancreatic Cancer: Novel Therapy, Research Tools, And Educational Outreach, Ayrianne J. Crawford

Theses & Dissertations

Since the 1980’s, legislatures have invested immense effort into strategies to capitalize on the United States’ global lead in basic and translational research. This is largely motivated by the discrepancy the US faces in converting its world leading research discoveries and innovations into commercial products, relative to other countries. This truncated productivity leaves the US out of substantial GDP growth and reduces public access to new innovations. Proponents of government and university owned patents reason that enhanced public private partnerships narrow the gap between the technology transfer of basic research discoveries and accessible commercial products.

With these concepts of technology …

Examination Of Methylation Status And Occupancy Of Dna Methylation Modifying Proteins On Regulatory Regions Of The Dax-1 Gene, Caroline P. Riedstra

Master's Theses

Epigenetic modifications influence gene expression and thereby play a pivotal role in development and disease. Misregulation and mutations in the DAX-1 gene, or Dosage-Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, Critical Region on the X chromosome, gene 1, have been implicated in Adrenal Hypoplasia Congenita (AHC) and Dosage Sensitive Sex Reversal (DSS). The orphan nuclear hormone receptor DAX-1 is expressed predominantly in tissues such as the testes, ovaries, breast, adrenal cortex, and lung. Critically, DAX-1 may serve as an indicator of aberrant growth in these tissues. Here we hypothesize that DAX-1 is epigenetically regulated, specifically in cancer cells, thereby reducing its …

Increasing Public Health Mosquito Surveillance In Hidalgo County, Texas To Monitor Vector And Arboviral Presence, Clarissa D. Guerrero, Steven Hinojosa, Diana Vanegas, Niko Tapangan, Matthew Guajardo, Sara Alaniz, Narda Cano, Christopher Vitek, John M. Thomas, Valerie Hernandez, Juan Garcia Jr.

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

From 2016 to 2018, Hidalgo County observed the emergence of Zika virus (ZIKV) infections along with sporadic cases of Dengue virus (DENV) and West Nile virus (WNV). Due to the emergence of ZIKV and the historical presence of other mosquito-borne illnesses, Hidalgo County obtained funding to enhance mosquito surveillance and educate residents on arboviruses and travel risks. During this time period, Hidalgo County mosquito surveillance efforts increased by 1.275%. This increase resulted in >8000 mosquitoes collected, and 28 mosquito species identified. Aedes aegypti, Ae albopictus and Culex quinquefasciatus made up approximately two-thirds of the mosquitoes collected in 2018 (4122/6171). Spatiotemporal …

Characterization Of Metabolic Gene Expression In The Raw 264.7 Monocyte Cell Line, Lauren Macaisa

PANDION: The Osprey Journal of Research and Ideas

Immune cells undergo changes in gene expression and metabolism when activated by a foreign molecule. Although the changes are short-lived in response to an acute infection, they persist in disorders with underlying chronic inflammation. To understand how changes in gene expression relate to changes in metabolism, the expression of metabolic transporter proteins, was analyzed in response to chronic inflammation in a mouse monocyte cell line. Specifically, Glucose Transporter-1 (GLUT1), Monocarboxylate Transporter-1 (MCT1), Monocarboxylate Transporter-4 (MCT4), and Glutamate Aspartate Transporter (GLAST) were analyzed, and it was hypothesized that all the transporters would increase in expression in response to a prolonged inflammatory …