Molecular Genetics Commons^™

Genetic Screen For Regulators Of Pol4, A Dna Repair Polymerase In Saccharomyces Cerevisiae, Pasang Dolma Sherpa

Theses and Dissertations

In Saccharomyces cerevisiae, DNA polymerase 4 (POL4) is the beta repair polymerase, the product of the POL4 gene, and is involved in base excision repair (BER) and microhomology-mediated end joining (MMEJ). Despite its involvement in these repair pathways and its conservation across eukaryotes, deletion of POL4 shows no detectable phenotype under standard laboratory conditions. I hypothesized that unknown genes act as backup systems, providing redundant activities that allow pol4Δ cells to survive. To test this, a genetic screen for mutants showing synthetic lethality with pol4Δ was implemented. I constructed a strain lacking the POL4 gene and carrying …

Metagenomic Profiling Of Gut Microbiome Signatures Across Liver Disease Stages And Hcv-Related Hepatocellular Carcinoma In Egyptian Patients, Marwa A. Zahra

Theses and Dissertations

Dysbiosis in the gut microbiome, particularly concerning the synchronous crosstalk between the gut and the liver, has been associated with various diseases. This study profiles the gut microbiome in liver diseases among Egyptian patients, with a focus on the hepatitis C virus (HCV) and hepatocellular carcinoma (HCC), both of which are highly prevalent in Egypt. Utilizing shotgun metagenomic sequencing, we analyzed microbial gene catalogs and taxonomic profiles from 46 Egyptian patients categorized into five groups: healthy individuals, liver disease patients of different etiologies, post-HCV, treated HCV, and HCV-HCC patients. Healthy and treated HCV patients exhibited distinct microbial profiles characterized by …

Building A Cell Specific System For In Vivo Rna Imaging Of The Endogenous Actin Gene In C. Elegans, Jasmine A. Huerta Canete

Theses and Dissertations

Messenger RNA (mRNA) plays a crucial role in protein synthesis and cellular processes, important for the development of cells such as neurons. When dysregulation occurs, it can lead to outcomes such as aberrant translation, causing neurodegenerative conditions to arise. Unfortunately, the localization of mRNA in an in vivo cell specific manner is still not understood. To address this, we decided to develop a cell-specific system to image RNA in vivo, within the organism known as C. elegans with a focus on the actin gene. The Actin gene encodes for an important cytoskeleton protein expressed ubiquitously, vital for the cell …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …

A Study To Identify The Causal Rare Genetic Variants In Primary Open And Closed Angle Glaucoma, Pseudoexfoliation Syndrome, And Associated Glaucoma, Suganya K

Theses and Dissertations

BACKGROUND: Glaucoma is the second most common cause of blindness globally typically diagnosed with a triad of clinical symptoms of increased intraocular pressure (IOP) with associated optic disc, optic nerve head (ONH) changes, and visual field defects. Genetic and environmental factors are some of the strong aetiology factors for glaucoma and identification of these factors has a potential implication in the management of the disease and its outcome. There is a paradigm shift towards understanding the genetics of glaucoma, wherein the variants in the nuclear, mitochondrial genome and other regulatory regions are being identified as contributing risk factors.

METHODOLOGY AND …

Identification Of Novel Argonaute Proteins Using A Metagenomic Mining Approach, Lobna Abdallah Ghonaim

Theses and Dissertations

Gene editing is one of the most promising tools in science. It enables precise modifications of an organism's genetic material. Metagenomics is considered a powerful tool that unlocks the broad genetic potential found in uncultured microbial communities. Exploring the genetic diversity of uncultured microbial communities helps identify novel functional proteins with unique properties and make the best use of these diverse microbial ecosystems.

We developed and employed a metagenomic-based approach to mine more than 1000 metagenomes for prokaryotic argonaute proteins (pAgos), a potential gene editing machinery encoded in bacterial and archaeal genomes. Our workflow involved strict quality control, sequence assembly, …

Investigating The Thermodynamic Properties Of Fat10 And Fat10ylated Proteins, Aravind R

Theses and Dissertations

Degradation of proteins by the proteasome is crucial in regulating protein levels in the cell. Post-translational modifications, such as ubiquitylation and Fat10ylation, trigger proteasomal degradation of the substrate proteins. While ubiquitylation orchestrates multiple cellular processes, Fat10ylation is primarily involved in the inflammatory response. Unlike ubiquitin, recycled upon substrate degradation, Fat10 is degraded along with its substrate. Although the thermodynamic properties of the substrate are critical for effective proteasomal degradation, they remain poorly understood for the Fat10-proteasome pathway.

Here, we demonstrate that Fat10 exhibits markedly lower thermodynamic stability and faster unfolding kinetics compared to ubiquitin. This is due to the absence …

Exploring The Role Of Transcription Factor Nrf1 In Autophagy And Inhibiting The Nrf1 Bounce-Back Response, Madison A. Ward

Theses and Dissertations

Cells exposed to proteotoxic stress invoke adaptive responses aimed at restoring proteostasis. Our previous studies have established a firm role for the transcription factor Nuclear factor-erythroid derived-2-related factor-1 (Nrf1) in responding to proteotoxic stress elicited by inhibition of cellular proteasome. Following proteasome inhibition, Nrf1 mediates the synthesis of new proteasomes, thus enabling cells to mitigate proteotoxic stress. Here, we report that under similar circumstances, multiple components of the autophagy-lysosomal pathway (ALP) were transcriptionally upregulated in an Nrf1-dependent fashion, thus providing the cells with an additional route to cope with proteasome insufficiency. In response to proteasome inhibitors, Nrf1-deficient cells exhibited profound …

Investigating Mitochondrial Stress Response Mechanisms In Aging, Aileigh E. Daniel

Theses and Dissertations

Mitochondrial dysfunction is widely recognized as a key contributor to aging and age-related diseases. The concept of mitohormesis suggests that low levels of ROS can activate stress-responsive transcription factors, promoting adaptive mechanisms that enhance longevity. We hypothesized that changes in protein abundance under conditions of mild mitochondrial stress reflect an adaptive response, and that commonly altered proteins across diverse genetic backgrounds of mitochondrial stress can help identify key regulators of stress resilience and aging. Our study identified conserved mitochondrial stress response pathways and highlighted candidate regulators for further investigation. These regulators appear to impair mitochondrial energy production by downregulating ATP …

Next Generation Sequencing Based Profiling Of Genes In Patients With Syndromic Forms Of Retinitis Pigmentosa, Harshavardhini G

Theses and Dissertations

India is one of the largest populations in the world and is estimated to have a high prevalence of Retinitis Pigmentosa (RP). RP is clinically and genetically heterogenous, characterized initially as night blindness, leading to complete vision loss due to retinal degeneration. RP can occur in non-syndromic or syndromic forms, affecting other organs as observed in Bardet Biedl Syndrome (BBS) and Usher syndrome (USH).

BBS is characterized by RP, polydactyly, obesity, renal anomalies and learning difficulties. USH is characterized by RP and sensorineural hearing loss (SNHL), with variable presence of vestibular dysfunction. Nextgeneration sequencing (NGS) has become a cost-effective technology …

Developing Coexpression Systems To Introduce Hydroxyproline Into Protein Engineered Collagen Peptides Utilizing Hydroxylase From Acanthamoeba Polyphaga Mimivirus, Jennifer Soldatich

Theses and Dissertations

A major challenge of developing collagen mimetic peptides (CMPs) by bacterial expression is to include hydroxyproline for biomedical applications. Coexpression of Prolyl-4-hydroxylase from A.mimivirus with CMPs was investigated. Additionally, four expression designs were created for potential applications in mammalian cells to utilize their natural ability of proline-hydroxylation by post-translational modification.

Interleukin 24 Induces Apoptosis Through Glycogen Synthase Kinase-3 Beta Inactivation In Prostate Cancer Cells, Sual J. Lopez, Moira Sauane

Theses and Dissertations

Interleukin 24 (IL-24) is a tumor-suppressing protein currently in clinical trials. IL-24 induces cancer-specific apoptosis by activating endoplasmic reticulum (ER) stress and mitochondria dysfunction. We have previously demonstrated that IL-24 leads to apoptosis in cancer cells by protein kinase A (PKA) activation in human breast cancer cells. To further understand the mechanism by which IL-24 induces apoptosis, I analyzed the role of glycogen synthase kinase-3 (GSK3), a highly conserved and normally active serine/threonine kinase in cancer cells and downstream target of PKA. The work reported here provides direct evidence that GSK3 was inhibited following IL-24 treatment in human prostate cancer …

Plk1 Overexpression Drives Tumorigenesis In A Prostate Cancer Mouse Model, Emile Kachouh

Theses and Dissertations

Prostate cancer is the leading cause of cancer-related deaths among men worldwide, and the development of resistance to existing treatments necessitates the exploration of new therapeutic strategies, including combination therapies. This study investigates the role of Polo-like kinase 1 (PLK1), located on chromosome 16p12.2, as an oncogene in prostate cancer. We generated a transgenic mouse model with prostate-specific overexpression of PLK1 to closely mimic human prostate cancer progression. Quantitative PCR (qPCR) analysis was employed to characterize the molecular profile of PLK1, revealing its implication in multiple pathways. To further elucidate the functional consequences of PLK1 overexpression, we confirmed phenotypic progression …

The Splice Index As A Prognostic Biomarker Of Strength And Function In Myotonic Dystrophy Type 1, Marina Provenzano

Theses and Dissertations

Myotonic dystrophy type 1 (DM1) is a slowly progressive, multisystem disorder caused by a CTG repeat expansion in the DMPK 3’UTR that leads to global dysregulation of alternative splicing. The resulting decline in physical function is slow, and no reliable biomarkers exist for predicting disease progression; however, an RNA mis-splicing biomarker associated with weakness may have utility in predicting functional outcomes. Here we validate the Splice Index (SI) as a potential biomarker of DM1-associated strength and function. Muscle biopsies of the tibialis anterior were collected from DM1-affected individuals at baseline (n = 46) and 3-months (n = 34), along with …

Re-Programming Transcription Factor Function For Neuroscience Research Of Addiction: Investigating The Role Of Zinc Finger Proteins In Driving Cocaine Reinforcement In Mice, Joseph A. Picone

Theses and Dissertations

Administration of addictive drugs like cocaine or morphine initiates aberrant gene transcription within brain reward circuitry neurons, which contributes to the lasting behavioral maladaptations that define addiction. The drug-induced expression and function of key brain transcription factors (TFs) is one major mechanism through which these drugs are able to regulate transcription, and as a consequence, lasting damaging drug-related behaviors including compulsive drug use. The goal of this dissertation is to more fully understand the molecular mechanistic drug-specific actions of TFs within the rodent nucleus accumbens (NAc). The findings from these studies could serve as the basis to identify novel candidate …

Role Of Human Intermediate Form Prl Receptor I-Tail In The Pathogenesis Of Breast Cancer, Shanwei Shen

Theses and Dissertations

Breast cancer continues to be the second most common cancer in women in the United States. The neuroendocrine hormone human prolactin (hPRL) plays an important role in normal mammary gland development and growth, stimulating normal breast tissue proliferation and differentiation. Considerable evidence has shown that hPRL is involved in the malignant transformation of human breast tissue. hPRL enhances viability, invasiveness, and proliferation of breast cancer cells in vitro. Evidence from epidemiologic and genetic studies also implicates role of hPRL in the pathogenesis of breast cancer. Its cognate receptor the human prolactin receptor (hPRLr) is required for the action of hPRL. …

Investigating The Impact Of Transcription On Mutation Rates, Sarah Patterson

Theses and Dissertations

tRNA genes are highly transcribed and perform one of the most fundamental cellular functions. Although a universal pattern observed across all three domains of life is that highly transcribed genes tend to evolve slowly, tRNA genes have been shown previously to evolve rapidly. This rapid sequence evolution could result from relaxed selection, increased mutation rate, or a combination of both. Here, we use mutation-accumulation line sequencing data to show that tRNA genes accumulate more mutations than other gene types. Our results indicate that this elevated mutation rate is a consequence of both elevated transcription-associated mutagenesis and a lack of transcription-coupled …

Increased Coding Potential Of Bovine Herpesvirus 1, Victoria Jefferson

Theses and Dissertations

Bovine respiratory disease (BRD) costs the cattle industry millions of dollars in costs in treatment and loss every year in the United States. A significant pathogen often contributes to BRD is Bovine Herpesvirus 1 (BoHV-1), a double stranded DNA virus with the ability to establish latency in the trigeminal ganglia and neurons. Primary infection with BoHV-1 results in immunosuppression that increases the risk of secondary bacterial infection and pneumonia. Because herpesviruses infect their hosts for life and can be reactivated in times of stress, BoHV-1 can present a recurring risk of BRD. The following research aims to expand the knowledge …

Gene Expression Effects On Productivity And Stress Tolerance In Polyclonal Plantings Of Populus Deltoides, Macy Gosselaar

Theses and Dissertations

Polyclonal plantings of Populus deltoides are expected to display increased site resource use, productivity, and tolerance to stress through plasticity changes leading to niche differentiation (i.e changes to crown/canopy structures). In the present study, P. deltoides Clones S7C8, 110412, and polyclonal plots were tested for differentially expressed genes and enriched biological pathways between planting schemes. Transcriptomic analysis of leaves revealed upregulation of an active growth gene and gene family members that play important roles in plant stress and stress tolerance in polyclonal plantings. A gene associated with oxidative stress was upregulated in polyclonal plantings across all treatments. Secondary metabolic pathways …

Molecular Diagnosis Of Non X-Linked Ectodermal Dysplasias Using Next Generation Sequencing, Eman Abdelalim Rabie

Theses and Dissertations

Ectodermal Dysplasias (EDs) are rare heterogenous monogenic developmental disorders sharing the impairment of at least two surface ectoderm-derived organs. Symptoms characteristically manifest developmental abnormalities of the teeth, and three skin derivatives: hair follicles, nails, and sweat glands. The disease-causing gene was identified for only fewer than half of 160 characterized ED phenotypes. Expectedly, ED-causing genes regulate or function in ectodermal-developmental processes. The most common phenotype is hypohidrotic ED featuring teeth agenesis, and diminished or complete absence of hair and sweat production. Disease-causing variants of EDA, EDAR, EDARADD and WNT10A genes were identified in 60-90% of ED patients in …

Novel Strategies In Head And Neck Tumor Therapy; Contribution Of Senescence In Therapy Response, And Resistance Development After Cisplatin Treatment, Fereshteh Ahmadinejad

Theses and Dissertations

Therapeutic outcomes achieved in head and neck squamous cell carcinoma (HNSCC) patients by concurrent cisplatin-based chemoradiotherapy initially reflect both tumor regression and tumor stasis. However, local, and distant metastasis and disease relapse as well as cisplatin-induced resistance are common in HNSCC patients. In the current work, we demonstrate that cisplatin treatment induces senescence in both p53 wild- type HN30 and p53 mutant HN12 head and neck cancer models. We also show that tumor cells can escape from senescence both in vitro and in vivo. We further established a cisplatin-resistant cell line from HN30 parental cell line that underwent brief senescence …

Examining Genetically-Informed Etiologic Models Of Co-Occurring Posttraumatic Stress Disorder And Recreational Cannabis Use Among College Students, Terrell A. Hicks

Theses and Dissertations

The college years encompass a period of increased risk recreational cannabis use (RCU), as well as a time of increased risk for trauma exposure and developing posttraumatic stress disorder (PTSD). Given the high co-occurrence between RCU and PTSD, and the potentially negative consequences of the two (e.g., worse academic outcomes), there is a need to understand the etiologic mechanisms of these commonly co-occurring conditions. Two primary phenotypic models exist: self-medication model (i.e., PTSD to RCU) and the high-risk model (i.e., RCU to PTSD). To date, there are two existing studies longitudinally examining the etiologic models proposed to explain co-occurring RCU …

Identification Of Pneumococcal Membrane Proteins Involved In Colonization/Biofilm Formation And Cognate Host Cellular Receptors, Yoonsung Hu

Theses and Dissertations

Colonization is prerequisite for infection and transmission of Streptococcus pneumoniae, or pneumococcus. Currently available pneumococcal conjugate and pneumococcal polysaccharide vaccines can provide protection against a limited number of capsular serotypes. Implementation of vaccines has decreased the frequency of invasive pneumococcal disease and their colonization rates, but only in a serotype-dependent manner. This has led to serotype replacement in pneumococcal ecology and increased invasive disease caused by non-vaccine serotypes. Development of conserved protein-based vaccine that can provide protection against all pneumococcal serotypes is needed. Numerous surface proteins are conserved in all serotypes, and some are known to be involved in …

Knockdown Of Mdm2 In Hepg2 Cell Line: A Step Towards Understanding The Relation Between Mirna590-3p And Its Downstream Target Gene, Mdm2, In Hepatocellular Carcinoma, Jihad Mahmoud

Theses and Dissertations

Background: miRNA 590-3p is a small non-coding RNA that has previously been associated with the occurrence and progression of several cancer types. Its expression pattern and biological role in Hepatocellular carcinoma (HCC), however, remain controversial. Interestingly, a previous study in our lab revealed a tumor suppressing activity of miR-590-3p in HCC and identified the MDM2 gene as the miR-590-3p target gene.

Aim: The current study aimed to knock down the expression of MDM2 in HepG2 cells to understand how the inhibition of MDM2, as a validated downstream target of miR-590-3p, would affect different functional pathways in HCC. In …

Alternatively Spliced Csf3r In Human Health And Disease, Borwyn A. Wang

Theses and Dissertations

Elevated alternative colony stimulating factor 3 receptor (CSF3R) isoforms are observed in myelodysplastic syndromes (MDS) and other myeloid neoplasms, but their role in driving disease progression has not been fully explained. In this study we report on the role of an MDS-associated splicing factor SRSF2 and its effects on the production of Class III and Class IV CSF3R isoforms and granulopoiesis. Class IV add-back in Csf3r-null mice showed impaired neutrophil differentiation with increased number of CFU-G, which largely consisted of metamyelocytes, while Class III showed greater dysgranulopoiesis accompanied by dysmorphic neutrophils. Alternative CSF3R isoforms were elevated in …

Development Of Novel, Miniaturized Sperm Cell Isolation Techniques For Sexual Assault Samples, Brittany Celeste Hudson

Theses and Dissertations

The ever-increasing sexual assault evidence collection kit backlog within the United States has prompted the search (and desperate need) for a more efficient, cost-effective, and rapid processing technique that can separate male and female contributions from evidentiary samples. Although backlogs have largely been tackled across the United States and many technological advancements have made the forensic DNA analysis workflow quicker, techniques for handling sexual assault samples remain time-consuming, tedious, and inefficient at separating cellular fractions from the victim and perpetrator. Thus, this research sought to identify a reproducible sperm isolation method using antibodies and/or alternative differential cell lysis techniques as …

Identifying The Human Homologs Of Yeast Rab Proteins Ypt10 & Ypt11 And A Global-Scale Louse Endosymbiont Genome Variation, Nathaniel P. Smith

Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease that causes loss of upper and/or lower motor neurons, and currently has no treatment or cure available. Over 90% of cases occur spontaneously with unknown causes, highlighting the complexity of the disease, and only 10% of cases are linked to heritable genetic mutations. Numerous ALS-linked genes are conserved through evolution, and model organisms may therefore provide opportunities to understand disease pathology at a molecular or cellular level, proving instrumental in identifying therapeutic targets. ALS subtype 8 (ALS8) is caused by an autosomal dominant P56S mutation in the VAPB gene that …

Insights Into Halophilic Microbial Adaptation: Analysis Of Integrons And Associated Genomic Structures And Characterization Of A Nitrilase In Hypersaline Environments, Sarah Sonbol

Theses and Dissertations

Hypersaline environments are extreme habitats that can be exploited as biotechnological resources. Here, we characterized a nitrilase (NitraS-ATII) isolated from Atlantis II Deep brine pool. It showed higher thermal stability and heavy metal tolerance compared to a closely related nitrilase.

We also studied integrons in halophiles and hypersaline environments. Integrons are genetic platforms in which an integron integrase (IntI) mediates the excision and integration of gene cassettes at specific recombination sites. In order to search for integrons in halophiles and hypersaline metagenomes, we used a PCR-based approach, in addition to different bioinformatics tools, mainly IntegronFinder.

We found that integrons and …

Identifying Genes Downstream Of Mef2 That Influence Ethanol Sedation In Drosophila Melanogaster, Ananya Talikoti

Theses and Dissertations

Alcohol use disorder is a global public health issue that affects millions across the world. It can result in negative physical and mental health outcomes, and currently treatment options are limited and rates of relapse are high. Identifying genes that affect aspects of ethanol behaviors in model organisms, such as Drosophila melanogaster, can serve to eventually develop more robust therapeutic interventions for those experiencing alcohol dependence. Previous studies have identified a relationship between a person's initial sensitivity to alcohol and their abuse potential for the drug in later life. Therefore, we can study sedation behaviors in Drosophila melanogaster to …

A Spatiotemporal Assessment Of Fish Assemblage Response To Land-Use Change And The Evaluation Of Edna Metabarcoding For Describing Diverse Fish Communities, Timothy M. Owen

Theses and Dissertations

Fish assemblages are often assessed as a biological proxy for environmental health. While humans value healthy environments for the ecosystem services and recreational opportunities they provide, it is increasingly evident that such resources can be paradoxically degraded by anthropogenic activities. In this investigation, we studied the relationship between different intensities of anthropogenic land-use change and habitat-driven fish assemblage response across multiple spatiotemporal scales. Secondarily, we explored the efficacy of eDNA metabarcoding against conventional electrofishing techniques for the purpose of describing complete fish communities. This study was conducted in the Tuckahoe Creek basin near Richmond, Virginia. This James River tributary serves …