Molecular Genetics Commons^™

Characterizing Endogenous Dicer Products To Unravel Novel Rnai Biogenesis Pathways, Jacob Oche Peter

Dissertations

ABSTRACT

RNA interference (RNAi) is a pervasive gene regulatory mechanism in eukaryotes based on the action of multiple classes of small RNA (sRNA). Exploiting RNAi pathways in non-model systems have great potential for creating potent RNAi technologies. Here, we accessed RNAi-mediated control of gene expression in the two-spotted spider mite, Tetranychus urticae (T. urticae) using engineered dsRNA designed to modulate the host RNAi pathway and increase RNAi efficacy. Analysis of Dicer (Dcr) generated fragments revealed how exogenous RNAs access the host RNAi pathway in this animal, opening avenues for designing RNAi technology for their control. Further, some organisms …

Development Of The Ark Assay For Quantitating Dna- Protein Crosslink Accumulation And Fanconi Anemia Pathway Involvement In The Repair Process, Naeh Klages-Mundt

Dissertations and Theses (Open Access)

DNA-protein crosslinks (DPCs) are a common DNA lesion naturally arising in cells, wherein protein becomes covalently and irreversibly bound to the DNA. Given their excessive size, these adducts present a significant challenge to replication and transcription, thus requiring timely and efficient repair. However, the precise mechanisms involved with processing DPC removal remain unclear. Moreover, current methodologies to quantitate DPC accumulation and removal are restrained by a range of limitations. Here, we describe and discuss a new DPC detection assay – the ARK assay – capable of overcoming the limitations incurred by prior assays. The design, which uses dual chaotropic lysis …

Disrupting Monoallelic Expression Of Variant Surface Glycoprotein In Trypanosoma Brucei By A Non-Lethal Mutation In Class I Transcription Factor A, Sarah Platt

Honors Scholar Theses

Human African trypanosomiasis (HAT) is a lethal disease caused by protozoan hemoflagellates of the genus Trypanosoma. Humans are vulnerable to two subspecies, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. At the crux of HAT lethality lie two uncommon genetic expression phenomena: monoallelic expression and antigenic variation. Combined, these mechanisms effectively shield trypanosomes from host immune systems, prolonging infections. Variant Surface Glycoproteins (VSGs) are the key outer membrane proteins involved in antigenic variation. By continuously changing the composition of cell surface antigens, trypanosomes can survive bouts of immunological detection and eventually traverse the blood-brain barrier. There are over two …

Effects Of Trans-Acting Factors On The Translational Machinery In Yeast, Brandon M. Trainor

Graduate School of Biomedical Sciences Theses and Dissertations

Synthesis of proteins, or translation, is a complex biological process requiring the coordinated effort of numerous protein and RNA factors. Central to translation is the ribosome, a complex macromolecular complex consisting of both ribosomal RNA (rRNA) and ribosomal protein (r-protein). Ribosomes are essential and are one of the oldest and most abundant biomolecules across all forms of life. In addition to the ribosome, translation requires messenger RNA (mRNA), transfer-RNA conjugated to an amino acid (aa-tRNA), translation factors, and energy in the form of ATP and GTP. Translation universally occurs in four major stages, initiation, elongation, termination, and recycling, with initiation …

Overcoming Obstacles In Protein Expression In The Yeast Pichia Pastoris: Interviews Of Leaders In The Pichia Field, Zoe Ingram, Abha Patkar, Dahoon Oh, Kevin K. Zhang, Christina Chung, Joan Lin-Cereghino, Geoff P. Lin-Cereghino

Pacific Journal of Health

The yeast Pichia pastoris (also known as Komagataella pastoris) has been used for over 30 years to produce thousands of valuable, heterologous proteins, such as insulin to treat diabetes and antibodies to prevent migraine headaches. Despite its success, there are some common, stubborn problems encountered by research scientists when they try to use the yeast to produce their recombinant proteins. In order to provide those working in this field with strategies to overcome these common obstacles, nine experts in P. pastoris protein expression field were interviewed to create a written review and video (https://www.youtube.com/watch?v=FyC9xXVLyD0). This review describes …

Comparative Genomics Methods And Applications, Emily N. Alden

Biomedical Sciences ETDs

Virtually all fields of biology have benefited from the advancements in comparative genomics technologies, specifically in the study of evolution. In this dissertation I develop and use comparative genomic technologies to investigate the novel SARS-CoV-2 virus, assembly the first genome of the black lace domestic angelfish and identify germline genetic variants associated with altered breast cancer-specific survival. Our genome tiling array for the novel coronavirus presents a rapid and cost-effective method to sequence the entire viral genome and can be used to track the rapid evolution of viral variants in the population. The domestic angelfish is a member of the …

Implementing Crispr-Cas9 Gene Editing System In Microbotryum., Stevana Reese Schauer

College of Arts & Sciences Senior Theses

Microbotryum dianthorum is a species of smut fungus which causes infection in plants in the Dianthus genus. The infection process is aided by small-secreted proteins known as effectors. Effectors may aid in the infection process because they are secreted by the fungus and can enter plant tissue, possibly to facilitate infection and/or manipulate the host. Thus, it is of interest to investigate the genes for these effectors to determine their role in the infection process. One method to study genes is through gene disruption, via the CRISPR/Cas9 gene editing system, but this has not yet been implemented in Microbotryum dianthorum …

A High-Throughput Approach To Characterizing Arv1 On The Regulation Of Lipid Homeostasis Uncovers A Novel Interaction With Epidermal Growth Factor Receptor, Nicholas Anthony Wachowski

Graduate School of Biomedical Sciences Theses and Dissertations

Acyl-CoA cholesterol acyl transferase related enzyme-2 required for viability 1 (ARV1) was first recognized in Saccharomyces cerevisiae in a study done in 2000 by Tinkelenberg et al. In yeast, the deletion of ARV1 results in numerous defects including abnormal sterol trafficking [1], the reduction of sphingolipid metabolism [2], synthesis of glycosylphosphatidylinositol (GPI) anchor [3], ER stress [4], and hypersensitivity of fatty acids leading to lipoapoptosis [5]. Arv1 germline deletion in mice displayed a lean phenotype with increased energy [6]. In humans, ARV1 mutations lead to epileptic encephalopathy [7].

Non-alcoholic fatty liver disease (NAFLD) consists of simple steatosis to non-alcoholic steatohepatitis …

Slowing Down The Clock: Cellular Senescence And Aging, Saad Bhatti

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

No abstract provided.

Genetic Mouse Models Of Liver Disease: Potential Roles Of Zhx2 (Afr1) And Afr2 In Damage And Regeneration, Courtney P. Turpin

Theses and Dissertations--Pharmacology and Nutritional Sciences

The liver is the largest internal organ in mammals and responsible for carrying out various processes, including lipid and carbohydrate metabolism, detoxification of chemicals, and production of serum proteins. Liver damage, which can be caused by a variety of agents including viral infection, environmental toxins, alcohol and excessive dietary fats, can cause dysregulation of these critical functions, leading to worsening liver pathophysiology and impacting health. However, the liver has the remarkable ability to regenerate when damaged. Hepatocytes, which comprise a majority of liver cells, are relatively quiescent under healthy conditions. Upon injury, remaining hepatocytes can proliferate to recover from liver …

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 …

Single-Fluorophore Sensors For Mechanical Force In Living Cells, Sarah Kricheff

Honors Scholar Theses

Mechanotransduction is the process by which a mechanical stimulus is converted to a cellular signal. This process is heavily influential of cell morphology, differentiation, and behavior. However, altered levels of mechanical stimuli are also found in many pathological contexts. For example, cancerous cells have stiffer surrounding tissue than healthy cells, and research suggests that this alters cell behavior and promotes metastasis. Despite these findings, the cellular processes behind these signaling alterations remain widely unknown. Understanding these cascades is critical, as involved proteins can give us a deeper understanding of the role of mechanotransduction, and certain proteins can potentially be targeted …

A Context-Forward In Vivo Functional Genomics Platform For Target Discovery And Establishing Vulnerability Context In Pancreatic Cancer, Johnathon Rose, Johnathon Lynn Rose

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a very poor patient prognosis (5-year survival of ≤ 7%). While transcriptional profiling has aided in the classification of this disease into at least two broader subtypes, this alone has so far been insufficient to inform on more nuanced patterns of oncogenic dependency. We hypothesized that a more comprehensive and granular characterization of PDAC disease diversity is required to establish relevant context for targeted therapy. To this end, we sought to establish an integrated platform to: i) more comprehensively characterize differential oncogenic signaling across our tumor models, and ii) establish …

The Impact Of Sample Processing And Media Chemistry On The Culturable Diversity Of Bacteria Isolated From A Cave, Katey E. Bender, Katelyn Glover, Alexander Archey, Hazel A. Barton

International Journal of Speleology

Although molecular approaches can identify members of microbial communities in the environment, genomic information does not necessarily correlate with environmental phenotype. Understanding functional roles can be done by cultivating representative species, yet the culturablility of bacteria from caves remains low, at 0.02%, limiting our understanding of microbial community interactions and processes. We have investigated several factors influencing culturability of bacteria from a single sample location in Maxwelton Sink Cave, WV, USA. Extended incubation of inoculated plates showed a significant increase in colony counts from two to four weeks, indicating that extended incubations increase culturability. There were no significant differences in …

Role Of Nurd In Acute Leukemia Cell Survival, Javeria Aijaz

Theses and Dissertations

Depletion of the ATPase component of the Nucleosome Remodeling and Deacetylase (NuRD) complex, CHD4, reduces acute myeloid leukemia (AML) cell survival. This study identified other NuRD components, as potential therapeutic targets for disrupting protein-protein interactions within NuRD. In addition to AML, we established that T-cell Acute Lymphoblastic Leukemia (T-ALL) cell lines responded similarly to CHD4 depletion.

Greater than 90% depletion of either MBD2 or MBD3 (the mutually exclusive two DNA binding NuRD paralogues) – was unremarkable, but complete depletion of MBD3 increased apoptosis and genotoxic sensitivity. Combined depletion of MBD-NuRD proteins augmented apoptosis observed with complete MBD3 depletion - indicating …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

Mechanisms And Consequences Of Myb Gene Activation In Salivary Gland Tumors, Candace Frerich

Biomedical Sciences ETDs

Salivary gland adenoid cystic carcinoma (ACC) is an aggressive tumor with a tendency to infiltrate surrounding nerves and metastasize to distant sites. The standard treatment often fails to control local tumor recurrence and distant metastases and no approved targeted therapeutic options exist for these tumors. The goal of our studies was to reveal the molecular mechanisms driving ACC tumor development and novel drug targets to improve patient morbidity and mortality.

We first analyzed clinical and RNA-sequencing (RNA-seq) data for 68 formalin-fixed paraffin-embedded (FFPE) ACC tumor samples and described previously unappreciated molecular heterogeneity that predicts patient outcome. The poor outcome subgroup …

Elucidating Immune Signaling Of Influenza A Virus And Aspergillus Fumigatus Co-Infections Through Pioneered Model Development, Meagan Danyelle Rippee-Brooks

Graduate Theses/Dissertations

Bacterial co-infections with influenza A virus (IAV) are extremely serious and life-threatening. However, there exists limited understanding about the importance of fungal infections with IAV. Clinical case reports indicate that fungal co-infections do occur and suggest the IAV pandemic of 2009 had a propensity to predispose patients to secondary fungal infections more than previous IAV strains. IAV-fungal co-infections are marked by high mortality rates of 47 to 61% in previously healthy individuals between the ages of 20 and 60. Yet, the variables involved in this co-infection remain undetermined. I achieved effective recapitulation of this co-infection using a C57Bl/6 murine (mouse) …

Characterization Of Human Dutpase, Shawna Marie Rotoli

Graduate School of Biomedical Sciences Theses and Dissertations

Deoxyuridine nucleotidyl transferase (dUTPase) is an enzyme found in all organisms that have thymine as a component of DNA. It catalyzes the hydrolysis of dUTP to dUMP and pyrophosphate thus precluding the buildup of dUTP pools as well as providing the substrate, dUMP, for the de novo synthesis of thymidylate. In Homo sapiens, there are four isoforms: mitochondrial (mDut), nuclear (nDut), variant 3 and variant 4. This work is largely focused on nDut. Using structural and MS analyses of recombinant dUTPase constructs, an intermolecular disulfide bridge between cysteine-3 of each nDut monomer was discovered. It was found that these two …

A Discrepancy Between The Human Reference Genome (Grch37) And Transcriptome (Refseq) Results In The Incorrect Annotation Of A Clinically-Relevant Sequence Variant In Recql4, Lisa A. Lansdon

Research Days

No abstract provided.

Acute Promyelocytic Leukemia: A Case Study Correlating Cytogenetic Abnormality With Prognosis, Alyssa Lamond, Theresa Tellier-Castellone

Senior Honors Projects

Advancements in medical technology today have positively impacted the diagnosis, treatment, and prognosis of cancers. Particularly acute promyelocytic leukemia (APL) has completely improved from having the poorest prognosis to one of the best. Acute promyelocytic leukemia is a malignant disease of hematopoietic tissue classified by WHO as leukemia with >20% blasts from the myeloid lineage, specifically promyelocytes. Determined in 1976, FAB classified AML subtypes M1-M7, with APL being M3. Specific characteristics classify the subtype of AML, with each resulting from a different genetic abnormality. The focus of APL diagnosis, treatment, and prognosis occurs around the known PML-RARα fusion gene. Flow …

A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. While remarkable progress has recently been made towards understanding the structure of mitoribosomes, the unique pathways and factors that facilitate their biogenesis remain largely unknown. This dissertation defines the physiological role of an evolutionarily conserved yeast protein called Mam33 in mitochondrial ribosome assembly. The biomedical relevance of this finding stems from the fact that mutations or changes in its expression of the human ortholog p32 result in mitochondrial dysfunction. In human patients, bi-allelic mutations cause severe multisystemic defects in mitochondrial energy metabolism, …

Thiol-Based Misfolding: Linking Redox Balance To Cytosolic Proteostasis, Ford Amy

Dissertations and Theses (Open Access)

The eukaryotic cytosolic proteome is vulnerable to changes in proteostatic and redox balance caused by temperature, pH, oxidants and xenobiotics. Cysteine-containing proteins are especially at risk as the thiol side chain is subject to oxidation, adduction and chelation by thiol-reactive compounds. All of these thiol-modifiers have been demonstrated to induce the heat shock response and recruit protein chaperones to sites of presumed protein aggregation in the budding yeast Saccharomyces cerevisiae. However, endogenous targets of thiol stress toxicity responsible for these outcomes are largely unknown. Furthermore, I hypothesize proteins identified as redox-active are prone to misfolding and aggregation by thiol-specific …

Mechanisms Of Trinucleotide Repeat Instability During Dna Synthesis, Kara Y. Chan

Theses and Dissertations--Toxicology and Cancer Biology

Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a …

The Role Of Tumor Suppressor Dear1 In The Acquisition Of Mammary Stem/Progenitor Cell Properties, Uyen Le

Dissertations and Theses (Open Access)

Breast cancer is the most commonly diagnosed cancer in women in America. Ductal carcinoma in situ (DCIS), one of the earliest pre-invasive forms of invasive ductal carcinoma (IDC), has a 30-50% risk of progressing to IDC. Understanding the mechanisms regulating progression from DCIS to IDC would help identify biomarkers to stratify patients at higher risk of progression or metastasis. Cumulative literature suggests the earliest phase of dissemination from the primary tumor is driven by the epithelial-mesenchymal transition (EMT) program. DEAR1 is a tumor suppressor gene which is mutated, undergoes loss of heterozygosity in breast cancer, and is downregulated in DCIS …

Inhibition Of Ribosome Biogenesis Through Genetic And Chemical Approaches, Leonid Anikin

Graduate School of Biomedical Sciences Theses and Dissertations

In order to maintain the ability to generate proteins, proliferating cells must continuously generate ribosomes, designating up to 80% of their energy to ribosome biogenesis (RBG). RBG involves transcription of rDNA by RNA polymerases I (Pol I) and III (Pol III), expression of approximately 80 ribosomal proteins, and assembly of these components in a process referred to as ribosome maturation. During maturation, the Pol I transcribed 47S pre-rRNA undergoes a number of processing events, while simultaneously interacting with processing factors and ribosomal proteins that drive pre-ribosome assembly. Inhibition of RBG has become one of the pursued targets for cancer therapy …

Insight Into Translational Activation In Yeast Mitochondria, Julia Lynn Jones

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial function depends on over a thousand proteins, of which the majority are nuclear DNA-encoded and approximately one percent are mitochondrial DNA-encoded. The mitochondrial DNA of Saccharomyces cerevisiae contains eight protein-encoding genes, seven of which are required for proper function of the respiratory complexes and one encodes a ribosomal protein. The bigenomic nature of the oxidative phosphorylation complexes requires coordinated expression and regulation from both the nuclear and the mitochondrial genomes. It is currently unclear how this regulatory network operates. However, it is thought that nuclear genome-encoded messengers localized to the mitochondria aid in this coordination.

A family of proteins …

The Zinc Transporter Zipt-7.1 Regulates Sperm Activation In Nematodes, Yanmei Zhao, Chieh-Hsiang Tan, Amber Krauchunas, Andrea Scharf, Nicholas Dietrich, Kurt Warnhoff, Zhiheng Yuan, Marina Druzhinina, Sam Guoping Gu, Long Miao, Andrew Singson, Ronald E Ellis, Kerry Kornfeld

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Sperm activation is a fascinating example of cell differentiation, in which immotile spermatids undergo a rapid and dramatic transition to become mature, motile sperm. Because the sperm nucleus is transcriptionally silent, this transition does not involve transcriptional changes. Although Caenorhabditis elegans is a leading model for studies of sperm activation, the mechanisms by which signaling pathways induce this transformation remain poorly characterized. Here we show that a conserved transmembrane zinc transporter, ZIPT-7.1, regulates the induction of sperm activation in Caenorhabditis nematodes. The zipt-7.1 mutant hermaphrodites cannot self-fertilize, and males reproduce poorly, because mutant spermatids are defective in responding to activating …

Identification And Utility Of Dna In Exosomes, Paul Kurywchak

Dissertations and Theses (Open Access)

Cancer-associated mortality has been declining for two decades but remains a significant public health problem, especially when patients initially present with advanced disease. Early detection methods have improved survival rates but remain unavailable for a majority of cancers due to a lack of sensitive biomarkers or numerous limitations associated with current diagnosis strategies. Approaches to develop “liquid biopsies” by detecting tumor cells or DNA in the blood have led to several breakthroughs and create the potential for non-invasive, routine assessment of diseases status. However, these biomarkers are rare and currently difficult to isolate, especially in the early stages of disease. …

Mechanistic Insights Into The Regulation Of Mitochondrial Fission By Cyclin C, Vidyaramanan Ganesan, Katrina F Cooper, Randy Strich

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Cyclin C is a component of the mediator complex of RNA polymerase II that localizes to the nucleus under normal conditions. In response to stress, cyclin C translocates to the cytosol and mitochondria and mediates stress‐induced mitochondrial fission and apoptosis. The molecular mechanisms by which cyclin C induces mitochondrial fission are unknown. Using in vitro experimental approaches, we sought to investigate the mechanistic basis of cyclin C mediated mitochondrial fission.