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 …

Comparing Stress Levels And Experiences Between Mothers And Fathers Of Children With Angelman Syndrome, Katherine Helen Fix

Theses and Dissertations

Angelman syndrome (AS) is a neurogenetic disorder characterized by significant developmental and cognitive impairments, disruptive behaviors, and a hallmark happy demeanor. Past studies have shown that certain features of AS contribute to increased parental stress. Other studies report that in general the stress of parents of children with disabilities is influenced by stereotypical gender roles surrounding factors including daily care taking tasks, financial responsibility, and medical care involvement. This study aimed to compare perspectives among mothers and fathers of individuals with AS to identify discrepancies and themes relating to stress, specific hardships, and caregiving roles. Parents of children with AS …

Comparative Evolution Of Caenorhabditis Hermaphrodites, James Francis Kennedy

Theses and Dissertations

The Caenorhabditis genus produced three independently-evolved hermaphroditic species, C. elegans, C. briggsae, and C. tropicalis. This convergence happened by the independent co-option of male programs for use in a female body. This required two distinct steps: (1) mutations in the sex-determination pathway that activated spermatogenesis in XX animals, and (2) mutations that expressed one of the redundant sperm activation signals in XX animals. My project focused on characterizing how sex-determination genes work in C. briggsae and C. tropicalis. Loss-of-function alleles were used to compare the core sex-determination pathway to that of C. elegans. I found that the somatic sex-determination pathway …

The Yeast Checkpoint Kinase Mec1p Functions In Transcription Termination By Facilitating Recruitment Of Pcf11p And Regulating The Torpedo Exonuclease Rat1p, Riddhi Patel

Theses and Dissertations

My dissertation includes two projects, centered on transcription regulation by checkpoint kinases of the DNA damage response (DDR). The first project focused on the role of checkpoint kinase Mec1p in transcription termination and regulation of the torpedo exonuclease Rat1p. Termination, closely linked with pre-mRNA 3’ processing, dissociates RNA polymerase II (RNAPII) from DNA and releases the nascent RNA transcript. Efficient termination is required for maintaining a pool of RNAPII that is available for re-entry into new transcription cycle. Previous results showed that inactivation of Mec1p in the absence of exogenous genotoxic stress downregulates the efficiency of transcription termination. This study …

Characterization Of Microrna Expression In Neuron-Enriched Extracellular Vesicles During Early Life, Allison Molen

Theses and Dissertations

Extracellular vesicles (EVs) are membrane-bound sacs released by cells that carry molecular cargo reflective of their cell of origin. EVs enriched using L1 cell adhesion molecule (L1CAM) as a marker of putative neuronal origin can cross the blood–brain barrier and provide a minimally invasive window into brain-related processes. Exosomal microRNA (miRNA) regulate gene expression and have been implicated in psychiatric disorders, including major depressive disorder (MDD). However, measuring and analyzing miRNA from L1CAM-positive EVs presents substantial analytical challenges due to low abundance and sparse detection across samples.

Plasma samples from participants recruited through the Mid-Atlantic Twin Registry (MATR) were used …

From Gametes To Genes: Genetic Quality Assessment Of Anuran Cryopreserved Spermatozoa And Derived Embryos, Trinity Isabella Kassuhn

Theses and Dissertations

Sperm cryopreservation is an important tool within the suite of assisted reproductive technologies (ART) as it enables long-term storage of genetically valuable gametes. However, knowledge of the diagnostic criteria for assessing sperm quality and the genetic consequences of using cryopreserved sperm in amphibians is limited. This gap has raised concerns in captive breeding and reintroduction programs regarding the potential impact that cryopreserved sperm and the derived embryos may have on a population. The thesis aims to investigate how sperm cryopreservation affects the genetic material in both sperm and resulting embryos, with implications for in situ and ex situ amphibian populations. …

Foxo Factors’ Ability In Binding To And Inducing Tcf7 In Glioblastoma Cells, Stephanie Oyervides

Theses and Dissertations

Glioblastoma Multiforme (GBM) is an aggressive astrocytoma tumor type with a poor prognosis and limited immunotherapeutic options for those inflicted. Stem gene expression of this cancer indicates a direct relationship with the transcription factors, Forkhead box subfamily O (FOXO-1, -3 and - 4). These transcription factors are evolutionarily conserved, partially redundant. They are involved in diverse and fundamental biological processes such as cell survival, stem cell homeostasis, cell fate determination, cell cycle maintenance, metabolism, and apoptosis. Increasing evidence suggests interconnectivity between the WNT Pathway and FOXO transcription factors; however, the mechanism and full extent to which these interactions play a …

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 …

Increasing Diversity In The Genetic Counseling Profession: Determining Effective Career Education Strategies For Underrepresented Youth, Bryel Marie Frasch

Theses and Dissertations

Genetic counseling is a professional career path that is lacking in diversity, and diversity in healthcare has been shown to improve health outcomes. Studies suggest student engagement as a way to increase diversity, as early knowledge of genetic counseling increases the likelihood of considering it as a career and is especially true for racial or ethnic minoritized students. This study focused on educating high school students underrepresented in genetic counseling about the career and exploring the effectiveness of two different types of education methods (video vs in-person) to give valuable information for future outreach efforts. Upward Bound and Federal TRIO …

Newborn Screening For X-Linked Adrenoleukodystrophy: Experiences, Perspectives, And Future Directions For Genetic Counseling, Sophia Salvatore

Theses and Dissertations

There is a notable lack of research regarding genetic counseling practices for infants with screen-positive results for X-linked adrenoleukodystrophy (X-ALD) via newborn screening (NBS). The exploratory study aimed to understand the experiences of genetic counselors providing follow-up care for these infants, assess the complexities associated with NBS for X-ALD, identify potential gaps in genetic counseling practices, and describe the subsequent impact on patient care. A mixed-methods approach was utilized, incorporating an initial survey and optional semi-structured interviews with practicing genetic counselors who had seen a minimum of five cases of infants with screen-positive results for X-ALD in the last two …

Genetics Education Booklets Designed For Individuals With Intellectual Disability: Perspectives From Adults With Intellectual Disability And Genetic Counselors, Audrey Hyun Sook Parrott

Theses and Dissertations

Visual aid tools have been consistently suggested across literature aimed at identifying methods of improving health and genetics services for individuals with intellectual disability (ID). Aids written in plain language are suggested most often. The study intends to gain perspectives from adults with ID (AWID) and genetic counselors (GCs) on Easy Read genetics educational booklets designed for individuals with mild ID. We anticipate that GCs will find the booklets to be useful and accurate, and that AWID will find the booklets to be helpful to their understanding and comprehensible. The AWID were assessed via a self-reported survey, cognitively adapted for …

An Exploratory Study Of Disclosure Of X-Linked Conditions Between Mothers And Daughters, Madge Isabella Stuhlreyer

Theses and Dissertations

Carriers of X-linked conditions, both asymptomatic and symptomatic, face unique challenges regarding their experiences navigating the healthcare system and understanding implications of their carrier status. Studies show that mothers are known to be the main communicators of genetic information within their families, but in families affected with X-linked conditions, communication between mothers and daughters are hindered by factors such as lack of knowledge about the condition and reproductive implications, lack of emotional support, anxiety, and uncertainty about how to initiate these conversations. The purpose of this study was to explore the motivations behind mothers' decisions to initiate conversations with their …

Barriers In Receiving A Diagnosis Of Sanfilippo Syndrome: Perceptions From Healthcare Providers And Caregivers, Cassidy Lena

Theses and Dissertations

Sanfilippo syndrome (MPS III) is a rare, degenerative condition characterized by symptoms impacting neurological functioning, behavior, and quality of life. Diagnosis is often not made until three to six years of age, but comprehensive and effective symptom management have been reported to optimize patient longevity. The aim of this study was to identify barriers to diagnosis and the corresponding impact on patients. This study surveyed healthcare providers and caregivers of individuals with Sanfilippo syndrome. Both quantitative and qualitative methods were employed to assess provider knowledge and comfortability in managing Sanfilippo syndrome. Additionally, it explored caregiver perspectives on healthcare system navigation, …

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 …

Beyond Homogeneity: Exploring Causal Heterogeneity In Psychopathology, Philip B. Vinh

Theses and Dissertations

Traditional models in psychiatric research often impose assumptions of causal homogeneity, treating population-level associations as reflective of uniform underlying mechanisms. This dissertation challenges that assumption by introducing statistical and machine learning frameworks designed to detect and model causal heterogeneity in the development of psychopathology. Central to this approach is the advancement of finite mixture structural equation modeling (FM-SEM) to identify latent subgroups characterized by distinct, and sometimes opposing, causal pathways.

The dissertation comprises three integrated empirical studies. The first introduces mixDoC, a finite mixture extension of the classical Direction of Causation (DoC) model applied to twin data, enabling the detection …

Factors Influencing Adherence To Surveillance Guidelines In Individuals With Tuberous Sclerosis Complex, Kashish Khanna

Theses and Dissertations

Tuberous Sclerosis Complex (TSC) is a genetic condition that is caused by pathogenic changes in either the TSC1 or TSC2 gene and is characterized by multiple benign tumors, otherwise known as hamartomas, in various organs such as the brain, skin, lungs, and kidneys. Because of the many different clinical manifestations of TSC, extensive surveillance guidelines are recommended for individuals with TSC. Past studies have shown that there has been a gap in knowledge of these surveillance guidelines. These studies also suggest projects that measure adherence to surveillance guidelines and address specific challenges hindering surveillance guideline adherence. This study aims to …

The Relationship Between Cardiac Patient Beliefs And Experiences With Insurability And Their Decisions On Whether Or Not To Pursue Genetic Testing, Julia Schoeni

Theses and Dissertations

Since the enactment of the Genetic Information Non-Discrimination Act (GINA) in 2008, genetics providers have been incorporating conversations about GINA in pre-test counseling. There is currently limited evidence of the effects of personal or family histories of cardiomyopathy or aortopathy and associated genetic testing on patients seeking insurance policies not protected by GINA, including life, long term care, and disability insurance. This study aimed to determine whether individuals with a personal or family history of cardiomyopathy or aortopathy are having conversations about future insurability with their healthcare providers and how they perceive their ability to get these insurances when deciding …

Utilizing Evisits To Increase Access To Genetic Services For The Hearing Loss Population: A Tailored Service Delivery Model, Ansley Roberts

Theses and Dissertations

Purpose: Patients referred for genetics services have specific barriers decreasing accessibility, such as communication difficulties, long wait times, and misconceptions about the utility of genetic testing. We assessed a new tailored service delivery model used by the Greenwood Genetic Center to evaluate patients referred for hearing loss to determine if this model increases access to genetics services for individuals with hearing loss. Methods: Data points such as wait times, testing plan, and diagnostic yield were compiled from patient medical records. Comparison and analysis of data was completed by visit type, in-person, virtual, and electronic visits (eVisits), between October 2023 – …

Deciphering Evolutionary Co-Option By Studying The Origin Of Self-Fertility In Caenorhabditis Nematodes, Jonathan P. Harbin

Theses and Dissertations

In my research, I examined the characteristics of male and female sex-determination mutants in C. nigoni and investigated the regulatory pathway they define. This work tested whether flexibility in the sex-determination pathway was a preexisting condition that favored the origin of self-fertility in Caenorhabditis. Furthermore, I developed an approach for using interspecies hybrid mutants to assess the robustness of the C. nigoni pathway. My findings showed that the C. nigoni pathway is highly robust and canalized, suggesting that changes leading to self-fertility must have involved the impairment of this canalization in the germ line, to allow eventual alteration of germ …

Perspectives From Caregivers For Children With Retinoblastoma: Psychosocial Concerns And Genetic Counseling, Kayla Marie Lashinger

Theses and Dissertations

Caregivers play a vital role in the care of children affected with retinoblastoma as most cases are diagnosed before the age of five years old. While previous studies have explored the psychosocial needs of caregivers of children with pediatric cancer, these have not specifically focused on retinoblastoma in the United States (US). Prior research identified the profound emotional burden in terms of depression, anxiety, guilt, isolation, and loneliness experienced by caregivers. Given previous findings and the National Cancer Institute’s recommendation for genetic counseling and testing for all individuals affected with retinoblastoma, this study aimed to assess psychosocial concerns in relation …

The Autistic Adult's Perspective On Genetic Testing In The Prenatal And Cancer Settings, Robin Lisa Urban

Theses and Dissertations

Prenatal and cancer genetic tests are recommended by many professional medical organizations. Previous studies have shown that autistic adults have a negative opinion towards genetic testing for autism but have not explored if this sentiment is shared for other types of genetic testing. We used a descriptive, web-based survey of autistic adults to assess their attitudes towards prenatal and cancer genetic testing (n=36). Our data showed that overall attitudes towards prenatal and cancer genetic testing are positive. Notably, participants had slightly more positive attitudes towards prenatal genetic testing related to neurodevelopmental disorders when compared to testing for disorders primarily affecting …

Assessing Obgyn Residents’ Knowledge, Attitudes, And Current Practices For Carrier Screening, Aubrey Morgan Surian

Theses and Dissertations

Obstetricians and gynecologists (OBGYNs) are the main providers that order carrier screening on a regular basis, so it is important to understand their knowledge, attitudes, and current practices regarding this screening. There are two primary professional organizations that have established practice guidelines for carrier screening, the American College of Obstetrics and Gynecology (ACOG) and American College of Medical Genetics (ACMG). With the growth of pan-ethnic carrier screening, these guidelines have become remarkably different. This study aimed to assess resident OBGYN’s utilization of pan-ethnic carrier screening, discern any discrepancies between knowledge, attitudes, and current practices, identify possible practice resources that may …

Perception Of Alzheimer’S Actionability Among End Users Of Direct-To-Consumer Genetic Tests, Emily Mason

Theses and Dissertations

The APOE ε4 allele is the best-known genetic risk factor for developing late-onset Alzheimer’s disease. Although new evidence is emerging, the extent to which lifestyle improvements can reduce Alzheimer’s risk needs further investigation. Research suggests that individuals with a higher genetic risk may be more likely to engage in risk-reducing health behavior changes following results disclosure. This study aimed to better understand these findings by assessing the health behavior and perceptions of Alzheimer’s actionability among consumers of DTC genetic tests. Our study revealed that individuals with 2 copies of the APOE ε4 allele were less likely to make lifestyle modifications …

Patients’ Experience Of Care Following Perinatal Case Conference, Mary Elise Nolen

Theses and Dissertations

The Perinatal Case Conference (PCC) at Prisma Health-Midlands Maternal-Fetal Medicine (MFM) is a biweekly multidisciplinary meeting to discuss pregnancies with prenatally identified congenital anomalies. Patients are primarily cared for by MFM and may have appointments with various subspecialists during their pregnancy. The goals of the PCC are multidisciplinary collaboration in planning for the management of each pregnancy and familiarizing each practitioner with the pending cases, so if or when intervention is needed, the clinicians are familiar with the case.

Researchers performed a chart review and surveyed patients whose pregnancies were discussed in the PCC to learn the patient’s perspective of …

The Utility Of Referrals From A State Early Intervention System To A Pediatric Genetics Clinic To Increase Access To Genetic Services, Mikayla Jennings

Theses and Dissertations

Infants or toddlers enrolled in state early intervention programs have developmental delays or are diagnosed with conditions that may result in developmental delays. These infants receive a wide range of services from early intervention. In the state of South Carolina, children in the early intervention program are offered genetic evaluations at no cost to the family. Exploring the relationship between state early intervention systems and genetic clinics and the impact on this particular patient population can provide support for new and continued use of this service delivery model.

The purpose of this study was to evaluate the service delivery model …

Cancer Screening For Patients With Intellectual Disability: Exploring Parent And Caregiver Perspectives, Jennifer Ryan

Theses and Dissertations

Intellectual disability (ID) is defined as a combination of deficits in cognitive and adaptive function, both of which must be present early in life. Adults with ID frequently have unique healthcare needs; however, they also require care that is routine for all adults. This includes cancer screening. The goal of this study was to evaluate whether or not adults with ID are undergoing cancer screening, understand the barriers they have faced in obtaining screening, and collect recommendations from parents and caregivers on ways to improve access to and facilitate screening for this population. We surveyed parents and caregivers of adults …

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 …

The Genetic Architecture Of Cervical Change During Pregnancy: From Modeling To Mechanism — Does The Cervix Mediate Maternal Risk For Spontaneous Preterm Birth?, Hope M. Wolf

Theses and Dissertations

This project leverages clinical data and biospecimens from a prospective longitudinal cohort of pregnant women to study the genetic and phenotypic relationships between cervical shortening and the duration of pregnancy. Sonographic cervical length (CL) was measured throughout pregnancy in a cohort of 5,160 Black/African American women in Detroit, Michigan. Maternal DNA samples were sequenced with a next-generation low-pass whole genome platform. The heritability of cervical change during pregnancy and its genetic correlation with gestational age at delivery (GAD) were estimated using Genome-Wide Complex Trait Analysis. These estimates suggest that cervical change is heritable (h²CL = 51%) and highly polygenic trait. …