Genetic Processes Commons^™

Using Genetically Diverse Mice To Examine The Effects Of Environmental Enrichment Of The Transcriptome, Michael Richard Leonardo

Theses, Dissertations and Capstones

Environmental impoverishment is a model of early life stress with direct consequences across a wide range of neurological and physiological conditions. Neuron morphology and density as well as anxiety disorders and addiction have shown to have significant relationships with environmental impoverishment models. Conversely, environmental enrichment confers therapeutic benefits that are protective across these conditions. There is an observed spectrum of resistance or vulnerability to the effects of housing conditions across populations, indicating genetics as an influential factor. Understanding this interaction is critical for deepening our knowledge of how genes and environment interact in ways that confer resistance or vulnerability, and …

Advancing Novel Contrast Agents For Applications In Fluorescence-Guided Neurosurgery Using Fluorescence Cryotomography, Augustino Vittorio Scorzo

Dartmouth College Ph.D Dissertations

Fluorescence guided surgery (FGS) is an emerging surgical technique that aims to help surgeons identify tissue types to assist in surgical decision making - ideally providing “cut-by-color” guidance. A primary application for this approach is the identification of tumor tissue to achieve more accurate and complete tumor removal while simultaneously minimizing damage to surrounding normal tissue. The cornerstone of tumor visualization for FGS is the administration of fluorescent contrast agents, or in some cases metabolic precursors, designed to accumulate specifically in tumor tissue, and a wide range of agents that use different targeting mechanisms are currently under investigation. Although these …

Role Of Evolutionarily Conserved G4 Structures In Enhancer-Promotor Interactions, Shahem Alqudah

Honors Theses

Gene regulation is governed by complex networks of interactions between enhancers and promoters, regions of the genome that are typically distant from one another yet functionally linked through chromatin looping. Recent research has revealed the significant role of Gquadruplexes (G4s) in facilitating these interactions. This thesis explores the role of long Gquadruplex regions (LG4s) in enhancer–promoter communication, proposing that these regions mediate physical interactions between enhancers and their target promoters through direct G4:G4 interactions. Using a chromatin conformation capture (EQuIP-seq), electrophoretic mobility shift assays (EMSA), and luciferase reporter assays, the study demonstrates that LG4s may drive gene expression by promoting …

A Comparative Analysis Of Nf-Κb1 Gene Regulatory Sequence Methylation In Normotensive And Hypertensive Kenyans, Aaryan Barlas Piracha

Honors Theses

Accounting for the majority of deaths worldwide, non-communicable diseases (NCDs) present the greatest health challenge of the twenty-first century. Specifically, cardiovascular diseases (CVDs) exceed all other NCDs in annual deaths and especially affect low- and middle-income countries (LMICs). Hypertension, being the primary risk factor for CVD, affects over 75% of adults in LMICs due to inadequate health care and preventative measures. Additionally, epigenetic modifications of DNA are important mechanisms that regulate gene expression; DNA methylation, in particular, affects cytosine residues in cytosine-phosphate-guanine (CpG) islands on regulatory sequences. Previous research in our laboratory analyzed percent methylation at 8 different CpG islands …

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 …

Elucidating The Multi-Omics Of Early-Onset Colorectal Cancer, Jumanah Alshenaifi

Dissertations and Theses (Open Access)

The incidence and mortality rates of sporadic early-onset colorectal cancer have increased in recent decades, but there is no clear etiological basis for this trend. EOCRC is commonly defined as colon and rectal cancers diagnosed before the age of 50 years. The rising incidence of EOCRC has made it the second most common cancer and the third leading cause of cancer death in this age group. The rising incidence of EOCRC is also documented internationally in more than 20 countries across different continents. Clinically, EOCRC has a distinct, more aggressive clinical profile than LOCRC. While approximately 15% of EOCRC cases …

A Long Non-Coding Erna Forms R-Loops To Shape Emotional Experience-Induced Behavioral Adaptations, Rose Marie Akiki

MUSC Theses and Dissertations

Emotional experiences often evoke neural plasticity that supports adaptive changes in behavior, including maladaptive plasticity associated with mood and substance use disorders. These adaptations are supported in part by experience-dependent activation of immediate-early response genes, such as Npas4. We discovered that a conserved, long non-coding enhancer RNA (lnc-eRNA) transcribed from an activity-sensitive enhancer produces DNA-RNA hybrid R-loop structures that support 3D chromatin-looping of the enhancer and proximal promoter and stimulus-induced, rapid Npas4 gene induction. We also show that this Npas4 lnceRNA and its R-loops are required for the development of behavioral adaptations produced by chronic psychosocial stress or cocaine exposure, …

Deciphering Genotype-Phenotype Connections: Leveraging Pangenomes And Comprehensive Genome Variation, Flavia Villani

Alternative Theses and Dissertations (AETDs)

My thesis explores the application of advanced techniques for discovery of genetic variation and pangenomic approaches to enhance our understanding of genetic variation and genotype-phenotype relationships in two key model organisms: the HXB/BXH recombinant inbred rat family and the BXD mouse family. Through deep sequencing and innovative computational methods, I constructed com- prehensive pangenome graphs that captured genetic diversity beyond what is accessible through conventional single-reference approaches. In the HXB rat family, I identified approximately 200 million base pairs of sequence absent from the reference genome and discovered novel variants associated with glucose metabolism and chromogranin expression through phenome-wide association …

Targeting Prmt5 In Inflammation And Cancer: A Nexus Of Endotoxin Signaling, Antigen Presentation And Immune Evasion., Jimmy James Msemo

Theses and Dissertations--Medical Sciences

Protein Arginine Methyltransferase 5 (PRMT5) is a member of PRMT family that controls both intrinsic and extrinsic oncogenic processes [1]. Protein arginine methyltransferase 5 (PRMT5) is a type II methyltransferase that exerts widespread influence over gene expression, splicing, DNA repair, and immune regulation through symmetric dimethylation of arginine residues on histone and non-histone proteins [2]. The addition of methyl groups induces gene silencing through producing dictatorial histone marks like H2AR3ne2s, H3R8me2s and H4R3mes [3], which act as epigenetic repressive marks on gene promoters. In non-histone proteins, PRMT5 can methylate and regulate transcription factor proteins such as p53, E2F1, and p65, …

Characterizing A Rad23 Dependent Ultraviolet Radiation Resistance In Tetrahymena Thermophila, Emma June Liimatta

Graduate Theses/Dissertations

In 2020, 10 million deaths were attributed to cancer, with multidrug resistance being responsible for over 90% of deaths in cancer patients receiving treatment. This study utilized the model organism Tetrahymena thermophila to study how cells become resistant to Ultraviolet Radiation (UV) radiation, a process similar to multidrug resistance, specifically focusing on the nucleotide excision repair and ubiquitin shuttle protein Rad23. The National Cancer Institute documented 30-60% of cancers tested had a mutation in RAD23. Knockdown of RAD23 in Tetrahymena thermophila demonstrated a UV resistance phenotype with decreased nucleotide excision repair and differential expression of proteins active within caspase-independent …

Characterization Of The Overexpression Of Reca Homologs Rad51 And Dmc1 In Tetrahymena Thermophila, Jianna M. Cox

Graduate Theses/Dissertations

RecA homologs, Dmc1 and Rad51, work to repair DNA double-strand breaks (DSBs) within the cell through the recombination of homologous sections of DNA. Dmc1 works to repair programmed DSBs through meiotic recombination, while Rad51 functions to repair both meiotic and non-meiotic DSBs, the latter repaired through the process of homologous recombination repair (HHR). Chemotherapeutics, exogenous agents, work to form DSBs in cancer cells, attempting to inhibit the cell’s growth. A hyper recombinant phenotype is often seen in cancer cells due to the overexpression of RAD51, leading to drug resistance, the persistence of cancers, and an overall poor patient outcome. …

The Role Of Epigenetic Aberrations In The Cold Tumor Phenotype And Inflammatory Signaling In High-Risk Neuroblastoma, Pamela Morgan Watson

Alternative Theses and Dissertations (AETDs)

Neuroblastoma (NB) is a highly aggressive, heterogeneous disease that arises from the sympathetic nervous system (SNS) and originates from neural crest cells (NCCs) (1). NB is the most common extracranial cancer in pediatric accounts for 15% of pediatric cancer deaths (2). This high mortality rate is the result of the metastatic, immune evasive, and treatment resistant characteristics of the disease (3). It has been proposed that NB arises from blocks in differentiation during development, resulting in a mixture of two distinct cell types within the tumor: mesenchymal and adrenergic (Figure 1.1) (4,5). The adrenergic cell type is more differentiated, and …

Long G4-Rich Enhancers Physically Interacts With Promoters Via A G4:G4 Dna-Based Mechanism, Jeffrey David Demeis

Graduate Theses and Dissertations (2019 - present)

Enhancers are genomic sequences that function as regulatory elements capable of increasing the transcription of a given gene often located at a considerable distance. The broadly accepted model of enhancer activation involves bringing an enhancer-bound activator protein complex into close spatial proximity to its target promoter through chromatin looping. Equally relevant to the work described herein, roles for guanine (G) rich sequences in transcriptional regulation are now widely accepted. Non-coding G-rich sequences are commonly found in gene promoters and enhancers, and various studies have described specific instances where G-rich sequences regulate gene expression via their capacity to form G-quadruplex (G4) …

Can Mirna Be The Missing Link Between Parkinson’S Disease And Pesticides?, Fatma Gobba

Theses and Dissertations

Parkinson’s disease (PD) is a common neurodegenerative condition that leads to significant morbidity and a decline in the quality of life. It develops as a consequence of the loss of dopaminergic neurons in the substantia nigra pars compacta. Nevertheless, the development of PD is influenced by environmental factors, and the intricate nature of these relationships is further complicated by a multitude of factors, including the genetic backgrounds that are specific to populations and variations in environmental exposures, such as pesticides. Pesticides, consisting of a diverse family of chemicals commonly used in both agricultural and household settings to protect crops against …

The Role Of Liver-Specific Transcription Factor Hnf4 In Reprogramming Of Fibroblasts, Mary Odubote

Masters Theses

The mammalian liver, a vital organ with complex functions, relies on a network of transcription factors to regulate gene expression. Fusion of hepatoma cells with fibroblasts often leads to gene extinction, silencing approximately 400 liver-enriched genes, including critical transcription factors such as HNF4. Previous studies revealed that ectopic expression of HNF4 in fibroblasts failed to prevent the extinction of SERPINA1, a liver-specific gene, upon subsequent fusion with hepatoma cells. Here, we sought to investigate the extent to which ectopic expression of HNF4 can reprogram fibroblast cells and prevent gene extinction in hybrid cells.

Using whole-genome expression analysis, we compared RAT1 …

Evaluation Of The Cellular And Physiologic Impact Of Mitomycin C On Colon Cancer, Hannah Mcdonald

Theses and Dissertations--Clinical and Translational Science

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) with Mitomycin C (MMC) has more than doubled the overall and disease-free survival in patients with peritoneal metastases (PM) due to colorectal cancer (CRC) over the past two decades. Although MMC is the most used HIPEC drug for PM due to CRC, dosing protocols vary dramatically between and within institutions across the world. Additionally, little is known about the impact of hyperthermia and MMC on intracellular pathways for CRC. The aim of this work is to determine the optimal dosing strategy in the clinical application of MMC and hyperthermia for treatment of …

Regulation Of Diabetic Cardiomyopathy Through Mitochondrial Import Of Long Non-Coding Rnas, Andrew Dodge Taylor

Graduate Theses, Dissertations, and Problem Reports (ETD)

Introduction: The leading cause of mortality in patients with diabetes mellitus is heart failure. When mitochondrial health and function is disrupted, cardiac contractile function is compromised. Therefore, understanding mitochondrial regulation may benefit predicting and countering diabetic cardiomyopathy. MicroRNAs (miRNAs) play a crucial role in diabetic cardiac mitochondrial protein expression. Long noncoding RNAs (lncRNAs) have been shown to regulate miRNAs, but not in the mitochondrion. Additionally, it has yet to be confirmed if lncRNAs utilize the same mechanisms for mitochondrial import that miRNAs use, or if lncRNA presence in the mitochondrion fluctuates in diabetic mitochondria like miRNA presence does. The …

Pan-Cancer Genomic Characterization Of Human Papillomavirus Associated Tumors, Jeremiah Ray Holt

Theses and Dissertations (ETD)

Infection with high-risk human papillomavirus (HPV) accounts for nearly all cervical cancers (CESC), a subset of other anogenital squamous cancers, and increasing rates of head and neck squamous cell carcinomas (HNSC), with each cancer type having heterogenous outcomes due to a general lack of personalized care. Large scale genomic analyses have catalogued the somatic alterations occurring frequently among squamous tumor types including HNSC and CESC, but few studies have incorporated a thorough analysis of HPV genomics. High-risk HPVs are double-stranded DNA (dsDNA) viruses capable of integrating their genomes into host chromosomes, a phenomenon known to promote HPV-associated cancer formation. HPV …

Pdgfra And B Copositive Fibroblasts Drive Fibrosis In Mouse Salivary Glands Through Tgfβ Signaling, Renae Williams Atkinson

Electronic Theses & Dissertations (2024 - present)

Fibrosis is of significant concern to the medical community as numerous disease processes are characterized by progressive fibrosis leading to organ damage. We begin the process of examining the mechanism of fibrosis to salivary gland hypofunction and briefly consider Sjögren’s Disease (SjD). Method: We employed single-cell RNA sequencing data from a reversible mouse salivary gland injury model and from NOD/ShiLtJ mice, a model of secondary SjD. We performed treatment comparisons with the help of Seurat dotplots and UMAPS. Using differential gene expression analysis and the publicly available R packages: clusterProfiler, WikiPathways and Cytoscape, we identified the processes and pathways …

Employing A Machine Learning Approach In Precision Oncology To Predict Pik3ca Functional Status And Identify Phenocopying Variants Of Deleterious Pik3ca Mutations, Javier Castillo

CMC Senior Theses

The following proposal describes a modular machine learning approach that detects malfunctioning genes and pathways in cancer using the transcriptome of cancer patients. The transcriptome is underused in precision oncology and, combined with machine learning, can aid in the identification of hidden responders. Applied to the PI3K/AKT/mTOR pathway, this method can be used to predict PIK3CA functional status and identify phenocopying variants of deleterious PIK3CA mutations. The classifier will do this by integrating RNA-seq, copy number, and mutation data from tumors to determine the functional status of PIK3CA using a set of learned gene-specific weights. The classifier will then be …

Role Of Phosphorylated Dicer1 In Tumor Progression, Raisa Reyes-Castro

Dissertations and Theses (Open Access)

DICER1 is a multidomain enzyme discovered and widely recognized for its function in small non-coding microRNA (miRNA) synthesis. In cancer development, DICER1 functions as a haploinsufficient tumor suppressor which regulates miRNAs and Epithelial-to-Mesenchymal Transition (EMT). The Arur laboratory discovered that DICER1 is phosphorylated by active ERK and that ERK-mediated phosphorylation triggers DICER1 to translocate from the cytoplasm to the nucleus of cells in worms, mice and humans. Further, a heterozygous allele of a genetically engineered mouse model of phosphomimetic Dicer1 when combined with heterozygous Kras oncogenic background contributes to lung tumor progression in vivo. Mechanisms through which phosphomimetic Dicer1 …

Sperm Dna Integrity In Absolute Teratozoospermia Patients And Its Impact On Assisted Reproductive Technology Outcome, Dina Faris

Theses and Dissertations

Sperm DNA Fragmentation (SDF) is a common cause of male infertility, although it is underdiagnosed due to lack of routine testing. High levels of SDF are reported in men with abnormal sperm morphology. However, the implications of such findings on live birth following Intracytoplasmic Sperm Injection (ICSI) have not been studied in absolute teratozoospermia men (100% abnormal sperm morphology). In this prospective study, the severity of DNA damage was evaluated in absolute teratozoospermia patients and its impact on ICSI outcomes, particularly live birth rate. My study included 36 men with absolute teratozoospermia and 30 men with normal sperm. Real-time assessment …

Effects That The Methylenetetrahydrofolate Gene Mutation (Both The C677t And A1298c Polymorphisms) Have On Both Men And Women’S Fertility Abilities And Subsequent Fetal Development, As Well As What Nutritional Changes Can Possibly Do To Aid In Reversing These Supposed Negative Effects., Elizabeth Simkanin

Williams Honors College, Honors Research Projects

This study discusses the perceived negative effects of variants (C677T and A1298C) of the methylenetetrahydrofolate (MTHFR) gene on male and female fertility and fetal development, as well as the potential for nutrition changes to aid in reversing these negative effects. This research project was completed in order to discuss the possible association with and connection between nutrition and fertility in both male and female individuals who have either of the two most common MTHFR gene polymorphisms, 677C>T and 1298A>C. These two polymorphisms are of particular interest because they are associated with the most decreased activity of the MTHFR …

Dual Mechanisms Implemented By Lin-28 For Positive Regulation Of Hbl-1 Are Necessary For Proper Development Of Distinct Tissues In Caenorhabditis Elegans, Madeleine Minutillo

Graduate School of Biomedical Sciences Theses and Dissertations

In Caenorhabditis elegans, the heterochronic pathway is comprised of a hierarchy of genes that control the proper timing of developmental events. hbl-1 (Hunchback Like-1) encodes an Ikaros family zinc-finger transcription factor that promotes the L2 stage cell fate events of the hypodermis. The downregulation ofhbl-1 is a crucial step for the transition from the L2 to the L3 stage. There are two known processes through which negative regulation of hbl-1 occurs: suppression of hbl-1 expression by 3 let-7 miRNAs through the hbl-1 3’UTR and inhibition of HBL-1 activity by LIN-46. The mechanisms by which hbl-1 is positively regulated have not …

Infection And Transmission Determinants Of Flea-Borne Rickettsioses, Hanna J. Laukaitis

Graduate Theses and Dissertations (2019 - present)

The genus Rickettsia is comprised of Gram-negative, obligate intracellular bacteria that are spread by hematophagous arthropods. Elucidating the factors conferring rickettsial virulence has perplexed investigators for decades, complicated by the lack of efficient genetic tools necessary to uncover rickettsial- and vector-specific factors contributing to persistence. The advent of transposon mutagenesis has enabled the field to make vast developments in uncovering novel rickettsial mechanisms utilized in various host backgrounds. Thus, the aim of this study was to generate Rickettsia felis transposon mutants and characterize novel phenotypes associated with genetic disruption in an arthropod background. Distribution of rickettsiae is reliant on the …

Leveraging Single Cell Technologies For The Characterization And Treatment Of Refractory Pancreatic Cancer, Maria Monberg

Dissertations and Theses (Open Access)

Heterogeneity is a hallmark of cancer, and the advent of multimodal single-cell technologies has helped uncover heterogeneity in a high-throughput manner in different cancers across varied contexts at an unprecedented resolution. In an effort to improve precision medicine approaches in pancreatic ductal adenocarcinoma (PDAC), a highly lethal malignancy with a mere 11% 5-year survival rate, this dissertation focuses on first questioning the assumptions of the most basic models used to study PDAC via multimodal single-cell characterization methods at multiple levels of biological organization (scCNVseq and snATACseq for DNA assays, scRNAseq for transcriptomics, and paired protein assays such as multiplexed immunofluorescence …

How Environmental Change Will Impact Mosquito-Borne Diseases, Arsal Khan

Master's Projects and Capstones

Mosquitos, the most lethal species throughout human history, are the most prevalent source of vector-borne diseases and therefore a major global health burden. Mosquito-borne disease incidence is expected to shift with environmental change. These changes can be predicted using species distribution models. With the wide variety of methods used for models, consensus for improving accuracy and comparability is needed. A comparative analysis of three recent modeling approaches revealed that integrating modeling techniques compensates for trade-offs associated with a singular approach. An area that represents a critical gap in our ability to predict mosquito behavior in response to changing climate factors, …

Genetic Origins Of Polycystic Ovarian Syndrome (Pcos): An Analysis Of The Genetic Correlation Between Pcos And Insulin Receptor Mutations, Lauren Henry

Undergraduate Theses

Polycystic Ovarian Syndrome (PCOS) remains an extremely common, yet understudied syndrome experienced by 6-12% of females of reproductive age. Not only does it cause painful side effects manifesting both physically and mentally, but it also poses a threat to the fertility of those affected. For this reason, a more in-depth analysis to better understand how to detect this condition early and prevent fertility complications later is certainly warranted. PCOS is suspected to be primarily genetic due to correlations among immediate female family members. Based on previous research, a good starting point for analysis is the INSR gene. Various mutations within …

The Use Of Embark In Teaching About Genetic Relatedness, Anna Bonvillain, Tori Trammel

Honors Theses

Because of the increasing importance of precision medicine, it is vital that future healthcare providers master concepts related to genetic variation taught during their undergraduate classes. However, studies have shown that physicians often lack an adequate understanding of genetics, which serves as a hindrance to effectively caring for their patients. To address this issue, we created a collaborative active-learning protocol to improve pre-health students' comprehension of key concepts such as genetic relatedness and the source of genetic variation between siblings. Our worksheet guides students to compare the genetic profiles of two canine siblings using the Embark DNA genotyping platform. Embark …

Erα As A Modulator Of The Sle1b Lupus Susceptibility Locus And B Cell Receptor Signaling, Jared H. Graham

Theses & Dissertations

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by loss of immune tolerance and the production of anti-nuclear autoantibodies. 90% of lupus patients are women, and this sex bias is due to the actions of estrogens, which promote lupus pathogenesis. Our lab has shown that estrogen receptor alpha (ERα) mediates the effect of estrogens in lupus and that ERa acts in a B cell intrinsic manner to promote the development of autoantibodies and SLE. Genetic factors also contribute to lupus. One major lupus susceptibility locus, Sle1, controls loss of tolerance and autoantibody development as well as immune cell …