Genetics Commons^™

The Influence Of Genetic And Environmental Factors On Quit Attempt In Adolescent And Young Adult Twins, Gladys Langi

Theses and Dissertations

The purpose of this study was to examine the genetic and environmental influences on lifetime quit attempt in three US adolescent and young adult twin samples (N total = 6,322). The study utilized a common-contingent-causal (CCC) model to estimate these factors for lifetime quit attempts, after accounting for the factors for lifetime cigarette use and cigarettes per day. The study also examined age and sex differences, as well as the degree of relationship between these smoking phenotypes. The results demonstrated significant genetic influences for lifetime quit attempts in adolescents and young adults. No sex differences were observed for the contributions …

Comparisons Of Isogenic Trisomic And Disomic Cells From People With Mosaicism For Down Syndrome Unmask Cellular Differences Related To Trisomy 21, Kelly A. Rafferty

Theses and Dissertations

It is known that age-related changes impacting multiple organ systems occur earlier in people with Down syndrome (Ds), but the biological basis underlying this trisomy 21-associated propensity for premature aging is poorly understood. Given that the trisomic/normal cells from people with mosaic Ds (mDs) are identical with regards to environmental exposures and genes (except for chromosome 21 copy number), comparisons of these isogenic trisomic/disomic cells allow one to “unmask” the cellular consequences of trisomy 21 by removing extraneous factors. The primary aim of this study was to determine if trisomy 21 results in an increase in the acquisition of age-related …

Sh3 And Multiple Ankyrin Repeat Domain 3 (Shank3) Affects The Expression Of Hyperpolarization-Activated Cyclic Nucleotide-Gated (Hcn) Channels In Mouse Models Of Autism, Nikhil N. Shah

Theses and Dissertations

SH3 and multiple ankyrin repeat domains 3 (SHANK3) is a multidomain scaffold protein that is highly augmented in the postsynaptic density (PSD) of excitatory glutamatergic synapses within the central and peripheral nervous systems. SHANK3 links neurotransmitter receptors, ion channels, and other critical membrane proteins to intracellular cytoskeleton and signal transduction pathways. Mutations in SHANK3 are linked with a number neuropsychiatric disorders including autism spectrum disorders (ASDs). Intellectual disability, impaired memory and learning, and epilepsy are some of the deficits commonly associated with ASDs that result from mutations in SHANK3. Interestingly, these symptoms show some clinical overlap with presentations of human …

Evolution Of Antagonistic Relationships In Proteins: A Case Study Of Radialis- And Diviricata-Like Genes, Ao Gao

Theses and Dissertations

The antagonistic relationship of proteins describes the opponent interactions that result in one protein suppressing the function of another. Developmental genetic studies of Antirrhinum majus demonstrated that two transcription factors from the MYB gene family, RAD and DIV, interact through antagonism to regulate floral dorsoventral asymmetry. Interestingly, similar antagonistic interactions were found among proteins of FSM1 (RAD-like), MYBI (DIV-like), and DRIF in Solanum lycopersicum, which is involved in fruit development. Here, we report on the homology of these antagonistic MYB proteins based on reconstruction of the phylogeny of I-box-like and R-R-type clades, where RAD- and DIV-like belong, …

The Role Of Klf1 In Regulating Γ-Globin Gene Repressors, Anna P. Kovilakath

Theses and Dissertations

Sickle cell disease and β-thalassemia affect millions of people worldwide. γ-globin is the fetal counterpart to the adult β-globin. Research has shown that affected patients with higher than normal γ-globin show less severe symptoms. Therefore, reversing or preventing the hemoglobin switch from γ- to β- globin is a promising avenue of research for treating these diseases. KLF1 is an erythroid transcription factor involved in hemoglobin switching. Herein, we show that KLF1 directly regulates the γ-globin repressor gene LRF in both the mouse and human systems. KLF1 may also directly activate γ-globin expression by binding the promoter. In human HUDEP-2 cells, …

Investigation On Genetic Modifiers Of Age At Onset Of Major Depressive Disorder, Huseyin Gedik

Theses and Dissertations

Major Depressive Disorder (MDD) is a complex multifactorial disorder, which would lead to disability. Environmental and genetic factors are involved in MDD etiology. The aim of this project was to identify loci modifying age at onset (AAO) of MDD using survival models after adjusting for Childhood Sexual Abuse (CSA). To achieve this aim, a dataset was made available by the China Oxford and VCU Experimental Research on Genetic Epidemiology (CONVERGE) consortium. The study population had 5,220 controls and 5,282 cases with MDD. We performed two univariate association analyses using Cox Proportional Hazard (Cox PH) models. These two are Full Sample …

Epigenetic Editing To Validate Findings From Methylome-Wide Association Studies Of Neuropsychiatric Disorders, Robin F. Chan

Theses and Dissertations

DNA methylation is necessary for learning, memory consolidation and has been implicated in a number of neuropsychiatric disorders. Obtaining high quality and comprehensive data for the three common forms of methylation in brain is challenging for methylome-wide association studies (MWAS). To address this we optimized a panel of enrichment methods for screening the brain methylome. Results show that these enrichment techniques approach the coverage and fidelity of the current gold standard bisulfite based techniques. Our MBD-based method can also be used with low amounts of genomic material from limited human biomaterials. Psychiatric disorders have high prevalence and are often chronic …

Pnpase In C. Elegans: Mutagenic Analysis To Complement Knockdown Studies, Danielle K. Seibert

Theses and Dissertations

PNPase is a gene implicated as a potential target for cancer therapy; human mutations also present with deafness, myopathies, and neuropathies. In this study, C. elegans was used to investigate the effect of knocking out PNPase in a whole animal. C. elegans knockdown studies have reported an extended lifespan via an increase in ROS production. Further noted are larger mitochondria and an increase in fzo-1 expression. Knockout animals previously constructed using CRISPR/Cas9 were used for this study. We aimed to confirm these findings validating previous studies. It was discovered that PNPase knockout animals demonstrated a similar lifespan extension that was …

Drinking Motives Underlying Internalizing And Externalizing Pathways To Alcohol Misuse In College Students, Jeanne Savage

Theses and Dissertations

Alcohol misuse, including heavy episodic use and negative consequences, is a major public health concern and a particular problem among college students. The etiology of alcohol misuse is not well resolved, with multiple and often contradictory factors implicated in its development. Genetic factors influence alcohol misuse but few specific genes have been identified. A potential reason for these challenges is that alcohol misuse is phenotypically and genetically heterogeneous; that is, there are multiple causal pathways underlying its development. Previous typologies have suggested that distinct internalizing and externalizing pathways are involved, with corresponding differences in profiles of personality, temperament, and comorbid …

Integrating Genetics And Neuroimaging To Study Subtypes Of Binge Drinkers, Megan E. Cooke

Theses and Dissertations

Risky alcohol use is a major health concern among college students, with 40.1% reporting binge drinking (5 or more drinks in one occasion) and 14.4% reporting heavy drinking (binge drinking on 5 or more occasions) in the past month. Risky alcohol use is thought to be the result of a complex interplay between genes, biological processes, and other phenotypic characteristics. Understanding this complex relationship is further complicated by known phenotypic heterogeneity in the development of alcohol use. Developmental studies have suggested two pathways to risky alcohol use, characterized by externalizing and internalizing characteristics, respectively. However, the underlying biological processes that …

System Genetic Analysis Of Mechanisms Underlying Excessive Alcohol Consumption, Maren L. Smith

Theses and Dissertations

Increased alcohol consumption over time is one of the characteristic symptoms of Alcohol Use Disorder (AUD). The molecular mechanisms underlying this escalation in intake is still the subject of study. However, the mesocortical and mesolimbic dopamine pathways, and the extended amygdala, because of their involvement in reward and reinforcement are believed to play key roles in these behavioral changes. Multiple gene expression studies have shown that alcohol affects the expression of thousands of genes in the brain. The studies discussed in this document use the systems biology technique of co-expression network analysis to attempt to find

patterns within genome-wide expression …

Genome Wide Epigenetic Analyses Of Araptus Attenuatus, A Bark Beetle, Chitra Seshadri

Theses and Dissertations

Phylogeographic studies have relied on surveying neutral genetic variation in natural populations as a way of gaining better insights into the evolutionary processes shaping present day population demography. Recent emphasis on understanding putative adaptive variation have brought to light the role of epigenetic variation in influencing phenotypes and the mechanisms underlying local adaptation. While much is known about how methylation acts at specific loci to influence known phenotypes, there is little information on the spatial genetic structure of genome-wide patterns of methylation and the extent to which it can extend our understanding of both neutral and putatively adaptive processes. This …

Adducins Are Negative Regulators Of Migration And Invasion Of Normal Lung Epithelial Cells And Lung Cancer Cells, Parth Hitenbhai Amin, Parth Amin

Theses and Dissertations

Cell migration is an important component of many physiological and pathological processes such as tissue and organ morphogenesis during development, wound healing, inflammatory immune response, and tumor metastasis. The actin cytoskeleton is the basic engine driving cell migration. In the present study, we elucidate the role of an important actin interacting proteins, Adducins, in motility of normal lung epithelium and lung cancer cells. Adducins are the family of cytoskeleton protein capping the fast growing end and facilitating the bundling of actin filaments. Adducins are encoded by the three closely related genes namely alpha (ADD1), beta (ADD2) and gamma (ADD3) Adducin. …

A Mechanistic Study Of An Ipsc Model For Leigh’S Disease Caused By Mtdna Mutataion (8993 T>G), John P. Galdun

Theses and Dissertations

Mitochondrial diseases encompass a broad range of devastating disorders that typically affect tissues with high-energy requirements. These disorders have been difficult to diagnose and research because of the complexity of mitochondrial genetics, and the large variability seen among patient populations. We have devised and carried out a mechanistic study to generate a cell based model for Leigh’s disease caused by mitochondrial DNA mutation 8993 T>G. Leigh’s disease is a multi-organ system disorder that depends heavily on the mutation burden seen within various tissues. Using new reprogramming and sequencing technologies, we were able to show that Leigh’s disease patient fibroblasts …

Functional Significance Of Mtdna Cytosine Modification Tested By Genome Editing, Jason M. Robinson

Theses and Dissertations

The field of epigenetics is gaining popularity and speed, due in part to its capability to answer lingering questions about the root cause of certain diseases. Epigenetics plays a crucial role in regulation of the cell and cell survival, particularly by cytosine methylation. It remains controversial if DNMT’s which facilitate methylation are present in mammalian mitochondria and what the functional significance they may have on modification of mitochondrial DNA. CRISPR-Cas9 technology enabled genome editing to remove the MTS (mitochondrial targeting sequence) from DNMT1 of HCT116 cells, purposefully minimizing effects on nuclear cytosine methylation, while exclusively impacting mitochondrial modification. Removal of …

Investigating The Molecular Etiologies Of Sporadic Als (Sals) Using Rna-Sequencing, David G. Brohawn

Theses and Dissertations

ALS is an often lethal disease involving degeneration of motor neurons in the brain and spinal cord. Current treatments only extend life by several months, and novel therapies are needed. We combined RNA-Sequencing, systems biology analyses, and molecular biology assays to elucidate sporadic ALS group-specific differences in postmortem cervical spinal sections (7 sALS and 8 control samples) that may be relevant to disease pathology. >55 million 2X150 RNA-sequencing reads per sample were generated and processed.

In Chapter 2, we used bioinformatics tools to identify nuclear differentially expressed genes (DEGs) between our two groups. Further, we used Weighted Gene Co-Expression Network …

Examining Genetic And Environmental Influences On Alcohol Use And Externalizing Behaviors In African American Adolescents, Neeru Goyal

Theses and Dissertations

The aim of this thesis is to expand our understanding of the etiology of alcohol misuse and related disorders in African Americans using genetically informative study designs. Specifically, we take advantage of the candidate-gene approach and polygenic score analysis to extend the literature specific to African American populations. Chapter 2 explores gene x environment (GxE) interactions through the candidate gene approach to explore the relationship between two genes chosen on their potential relevance to stress response and adolescent alcohol use and misuse, among African American youth living in highly impoverished neighborhoods, as moderated by stressful life events. Chapter 3 implements …

Analysis Of Standard Dna Procedures On Feathers Of Late 19th To Late 20th Century Osprey (Pandion Haliaetus), Alia A. Hamdan, Catherine B. Viverette, Rodney J. Dyer

Rice Rivers Center Research Symposium

Species with well-documented demographic histories and well known perturbations to gene flow provide good models for understanding how historic events impact contemporary population genetic structure1,2. Osprey (Pandion haliaetus), a marine bird-of-prey, experienced steep declines after widespread organochloride pesticide (e.g. DDT) use in the mid-twentieth century 3, however, population genetic consequences remain unknown. Use of historic specimens can aid population genetic studies4,5, however, these samples can degrade over time impacting quantity and quality of extracted DNA5. We compared the concentrations of extracted DNA of Osprey feathers from museum and research collections to those of contemporary samples collected according to standard field …

The Role Of Tfec In Zebrafish Neural Crest Cell And Rpe Development., Samantha A. Spencer

Theses and Dissertations

Zebrafish (Danio rerio) show a unique pigmentation pattern comprised of three pigment cell types: melanophores, iridophores and xanthophores. Other pigmented cells include the retinal pigmented epithelium (rpe) which absorbs excess light in the eye and maintain the extracellular environment around the photoreceptors. While previous mutations in mitfa showed a role in regulating trunk melanophores, the rpe was not affected. TALENs and CRISPR-Cas9 systems were used to generate mutant zebrafish for tfec, a transcription factor expressed in both neural crest and rpe. Embryos with tfec mutations showed a loss of iridophore pigmentation, and delays in the pigmentation of …

Proof-Of-Concept Of Environmental Dna Tools For Atlantic Sturgeon Management, Jameson Hinkle

Theses and Dissertations

Abstract

The Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus, Mitchell) is an anadromous species that spawns in tidal freshwater rivers from Canada to Florida. Overfishing, river sedimentation and alteration of the river bottom have decreased Atlantic Sturgeon populations, and NOAA lists the species as endangered. Ecologists sometimes find it difficult to locate individuals of a species that is rare, endangered or invasive. The need for methods less invasive that can create more resolution of cryptic species presence is necessary. Environmental DNA (eDNA) is a non-invasive means of detecting rare, endangered, or invasive species by isolating nuclear or mitochondrial DNA (mtDNA) from the …

Phenotypic Characterization Of Pnpase Knockdown In C. Elegans, Laura A. Lambert

Theses and Dissertations

The multifunctional exoribonuclease protein PNPase is implicated as a potential target for cancer therapy as well as causing mitochondrial disorders in humans, but there has yet to be a whole animal knockdown model created. In this study, C. elegans was used to investigate the effect of knocking down pnpt-1, the gene that encodes PNPase. It was discovered that pnpt-1 knockdown significantly extends lifespan via an increase in superoxide production similar to other known mitochondrial lifespan extension pathways. Additionally, mitochondrial networks, size and respiration are affected indication of other mitochondrial dysfunction..

PNPase is also known to transport small RNAs into the …

Investigation Into The Specification Of Nurf Recruitment To The Genome, Marissa Mack

Theses and Dissertations

The nucleosome remodeling factor (NURF) is a mutli-protein complex that plays a role in the regulation of gene expression through its ability to remodel nucleosomes. The largest subunit of this complex, Bptf (Bromodomain PHD Finger Transcription Factor) is important for many cellular processes as a transcriptional regulator and improper function results in disease or malignancy. To further understand the genome-wide recruitment of the NURF complex, the interaction partner for the N-terminal PHD finger domain of Bptf was investigated through pull down assays followed by mass spectrometry. It was determined that this domain does not recognize histones; instead it recognizes a …

Functional Characterization Of Rai1 In Zebrafish, Joshua S. Beach

Theses and Dissertations

Smith-Magenis Syndrome (SMS; OMIM #182290) is a multiple congenital abnormality and intellectual disability (ID) disorder caused by either an interstitial deletion of the 17p11.2 region containing the retinoic acid induced-1 (RAI1) gene or a mutation of the RAI1 gene. Individuals diagnosed with SMS typically present characteristics such as ID, self-injurious behavior, sleep disturbance, ocular and otolaryngological abnormalities, craniofacial and skeletal abnormalities, neurological and behavioral abnormalities, as well as other systemic defects and manifestations. Previous work by Vyas in 2009 showed temporal expression of rai1 in zebrafish embryos as early as 9 hpf. We hypothesize that there is maternal …

A Systems Biology Approach To Detect Eqtls Associated With Mirna And Mrna Co-Expression Networks In The Nucleus Accumbens Of Chronic Alcoholic Patients, Mohammed Mamdani

Theses and Dissertations

Alcohol Dependence (AD) is a chronic substance use disorder with moderate heritability (60%). Linkage and genome-wide association studies (GWAS) have implicated a number of loci; however, the molecular mechanisms underlying AD are unclear. Advances in systems biology allow genome-wide expression data to be integrated with genetic data to detect expression quantitative trait loci (eQTL), polymorphisms that regulate gene expression levels, influence phenotypes and are significantly enriched among validated genetic signals for many commonly studied traits including AD.

We integrated genome-wide mRNA and miRNA expression data with genotypic data from the nucleus accumbens (NAc), a major addiction-related brain region, of 36 …

Snd1 Mediated Downregulation Of Ptpn23 In Hcc, Nidhi Jariwala

Theses and Dissertations

SND1 MEDIATED DOWNREGULATION OF PTPN23 IN HEPATOCELLULAR CARCINOMA

By Nidhi Jariwala, MS

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University, 2014.

ADVISOR: Dr. Devanand Sarkar

Associate Professor, Department of Human and Molecular Genetics Blick Scholar Associate Scientific Director, Cancer Therapeutics VCU Institute of Molecular Medicine Massey Cancer Center

ABSTRACT

Staphyloccocal nuclease domain containing protein 1 (SND1) is identified as an oncogene in multiple cancers, including hepatocellular carcinoma (HCC). SND1 regulates gene expression at transcriptional as well as post-transcriptional level and mediates molecular pathways that culminate into carcinogenesis. SND1 …

Acquired Epigenetic And Chromosomal Changes In Women Treated For Breast Cancer, Noran Aboalela

Theses and Dissertations

Improved survival for women receiving chemotherapy for breast cancer (BC) has been accompanied by the development/persistence of psychoneurological symptoms (PNS) that compromise their quality of life. The biological basis for these PNS is unknown, but could reflect the acquisition of soma-wide chromosomal/epigenetic alterations. An important first step in testing this hypothesis is to determine if somatic genetic/epigenetic changes arise and persist following treatment. To answer this question we longitudinally studied 71 women (ages 23-71) with early-stage BC and collected measures before chemotherapy (baseline), and 4 weeks (mid-chemo); six months (during radiation therapy for a subset of women); and one year …

Structural And Functional Characterization Of The Mbd2-Nurd Co-Repressor Complex, Megha Desai

Theses and Dissertations

The MBD2-NuRD co-repressor complex is an epigenetic regulator of the developmental silencing of embryonic and fetal β-type globin genes in adult erythroid cells as well as aberrant methylation-dependent silencing of tumor suppressor genes in neoplastic diseases. Biochemical characterization of the MBD2-NuRD complex in chicken erythroid cells identified RbAp46/48, HDAC1/2, MTA1/2/3, p66α/β, Mi2α/β and MBD2 to comprise this multi-protein complex.

In the work presented in Chapter 2, we have pursued biophysical and molecular studies to describe a previously uncharacterized domain of human MBD2 (MBD2_IDR). Biophysical analyses show that MBD2_IDR is an intrinsically disordered region (IDR). Despite this inherent …

Genetic Interaction Influenced By Fluvastatin And Tgfb, Rebekah Rifareal

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

I was looking for an opportunity to network with researchers at VCU and found this program that would provide the perfect atmosphere to do so. The added benefit of HERO was that I also got the opportunity to network with other undergraduates interested in research from VCU as well as other institutions.

Sjögren-Larsson Syndrome: Genetic Studies And Biochemical Characterization Of Human Fatty Aldehyde Dehydrogenase, Todd L. Kelson

Theses and Dissertations

Sjögren-Larsson syndrome (SLS) is an autosomal recessive disorder due to deficiency of the fatty aldehyde dehydrogenase (FALDH) component of fatty alcohol:NAD⁺ oxidoreductase (FAO). We investigated the enzymatic defect in SLS in order to elucidate the role of FALDH in fatty aldehyde and fatty alcohol metabolism.

Genetic studies were performed to investigate carrier detection for SLS. Cultured skin fibroblasts from normal controls, SLS obligate heterozygotes, and SLS homozygotes were assayed for FAO and FALDH activities using 18-carbon substrates. In SLS homozygotes, mean FAO and FALDH activities were 8% of normal, and there was no overlap between the homozygote and heterozygote …

Molecular And Cytogenetic Characterization Of De Novo Acrocentric Rearrangements In Humans, Lisa Gail Shaffer

Theses and Dissertations

I have studied 26 children who have a de novo rearrangement of the acrocentric chromosomes in order to understand the formation of these aberrations. The families include '25 probands ascertained for Robertsonian-type translocations, 13 between nonhomologous chromosomes and 12 between homologs, and one rea(21;21)(q22;q22). The parental origins of the de novo rearrangements were determined in 26/26 families using QFQ and NOR variants and/or RFLP analyses. While there was no overall difference in the sex distribution of the parents of origin, there were more maternally derived nonhomologous ("true" Robertsonian) translocations (8 mat: 5 pat) and more paternally derived homologous rearrangements (4 …