Life Sciences Commons^™

A Multispecies Perspective Into Dietary Genetic Adaptations And Ancient Migration In The Peruvian Andes, Kelsey Jorgensen

Wayne State University Dissertations

Successful adaptation to the high-elevation Andes would have required both cultural and biological adaptations by early human populations. These past adaptations continue to shape the evolutionary outcomes of both humans and non-human species today. A multispecies perspective was used to examine how humans and non-human creatures, specifically insects, were shaped by past human adaptations. This dissertation asked two primary questions: 1) Given the importance and evolutionary history of potato consumption in the Peruvian Andes, is a genetic adaptation to better digest potato starch detectable in present-day Peruvians? and 2) Using the Andean Potato Weevil (APW) phylogeny as a proxy, what …

Mnrr1: Understanding The Role Of A Novel Mitochondrial-Nuclear Regulator, Stephanie L. Gladyck

Wayne State University Dissertations

Mitochondria are complex organelles that generate most of the energy required to sustain life and function in metabolic and signaling pathways required to maintain cellular homeostasis. MNRR1 (mitochondrial nuclear retrograde regulator 1 or CHCHD2) is a small, bi-organellar twin CX9C protein that is emerging as an important regulator of mitochondrial function, apoptosis, and cellular stress by participating in mitochondrial-nuclear crosstalk. Our lab has previously shown that in the mitochondria, MNRR1 regulates complex IV (Cytochrome c oxidase or COX) and is able to finetune the oxidase function through phosphorylation status. We have also shown that during stress, mitochondrial MNRR1 levels deplete, …

Modulation Of Pharyngeal Health In Bacterial Diet-Dependent Survival, Deniz Sifoglu

Wayne State University Dissertations

ABSTRACT

MODULATION OF PHARYNGEAL HEALTH IN BACTERIAL DIET-DEPENDENT SURVIVAL

by

DENIZ SIFOGLU

August 2021

Advisor: Dr. Joy Alcedo Major: Biological Sciences Degree: Doctor of Philosophy Both diet and bacterial microbiome modulate insulin signaling, which regulates key physiological processes that are important for survival. However, the mechanisms through which diet and the microbiome modulate insulin signaling remain unclear. To understand these mechanisms, I turned to the nematode worm C. elegans, whose diet consists of different types of bacteria. Like humans and other animals, C. elegans has to modulate its responses to its diet and to bacteria to optimize its survival. Because …

Addressing The Issue Of Missing Heritability: The Importance Of Apoptosis In Hereditary Breast And Ovarian Cancer And Functional Assessment Of Tp53i3-S252*, Sophia Chaudhry

Wayne State University Dissertations

A quarter of all cases of ovarian cancer (OVCA) cases are due to inherited factors. However, much of the genetic risk remains unknown. We have previously established the importance of whole exome sequencing to answer the question for missing heritability. We identified clinically actionable and novel risk loci in the DNA repair and cell cycle regulation pathways by assessing a cohort of women diagnosed with OVCA, wildtype for BRCA1/BRCA2 and suspected to be hereditary due to family history of breast cancer/OVCA. Equally as important was the exploration and discovery of novel risk loci in the apoptosis pathway. A total of …

A Mechanism For Sex Determination In Dioecious Cultivated Spinach, Nicholas West

Wayne State University Dissertations

While unisexual flowers have evolved repeatedly throughout angiosperm families, the actual identity of sex determining genes has been elusive, and their regulation within populations remains largely undefined. Additionally, sex liability is often observed in unisexual plants and has been correlated to external and internal cues, suggesting that the genes responsible for unisexual morphology are not necessarily segregating but rather differentially regulated. Understanding these processes will be of significant theoretical and agronomical importance.

Cultivated spinach is a dioecious species in which an individual will bear alternative sexual organs. Previous work has identified spinach B class floral organ identity genes, SpAP3 and …

Validating Functional Mechanisms For Non-Coding Genetic Variants Associated With Complex Traits, Cynthia Ann Kalita

Wayne State University Dissertations

Genome-wide association studies (GWAS) have identified a large number of genetic variants associated with disease as well as normal phenotypic variation for complex traits. However challenges remain in determining the functional relevance of human DNA sequence variants. Even after fine mapping, most variants are located in non-coding regions making it difficult to infer mechanisms linking individual genetic variants with the disease trait. In addition, we do not know under which environmental conditions the sequence variants have a functional impact, and whether they become one of many factors involved in complex phenotypes at the organismal level.

Chapter 1 describes computational methods …

Missing Heritability And Novel Germline Risk Loci In Hereditary Ovarian Cancer: Insights From Whole Exome Sequencing And Functional Analyses, Jaime Lyn Stafford

Wayne State University Dissertations

While 25% of ovarian cancer (OVCA) cases are due to inherited factors, most of the genetic risk remains unexplained. This study addressed this gap by identifying previously undescribed OVCA risk loci through the whole exome sequencing (WES) of 48 BRCA1/BRCA2 wild type women diagnosed with OVCA, selected for high risk of genetic inheritance. Five clearly pathogenic variants were identified in this sample, four of which are in two genes featured on current multi-gene panels; (RAD51D, ATM). In addition, a high impact variant in FANCM (R1931*) was identified. FANCM has been recently implicated in familial breast cancer risk but is not …

Role Of Sirna Pathway In Epigenetic Modifications Of The Drosophila Melanogaster X Chromosome, Nikita Deshpande

Wayne State University Dissertations

Eukaryotic genomes are organized into large domains of coordinated regulation. The role of small RNAs in formation of these domains is largely unexplored. An extraordinary example of domain-wide regulation is X chromosome compensation in Drosophila melanogaster males. This process occurs by hypertranscription of genes on the single male X chromosome. Extensive research in this field has shown that the Male Specific Lethal (MSL) complex binds X-linked genes and modifies chromatin to increase expression. The components of this complex, and their actions on chromatin, are well studied. In contrast, the mechanism that results in exclusive recruitment to the X chromosome is …

Analysis Of The Secondary Neurodegenerative Consequences Of Primary Oligodendrocyte Stress Through The Use Of The Novel Obiden Mouse Model, Daniel Zdzislaw Radecki

Wayne State University Dissertations

The work of this project was to develop, test and characterize a potential novel mouse model of the neurodegenerative disease Multiple Sclerosis (MS). Historically, MS has been identified as a primary autoimmune disease of the central nervous system (CNS). However, treatments based on this view have met with limited success, and in most cases, fail to prevent progression of MS from mild to moderate and severe forms. Original observations regarding axonal and neuronal pathology in the white and gray matter of the CNS were rediscovered in the 1990s. These observations indicated that even in the absence of the immune system, …

Functions Of Atr/Mec1 In Meiosis And The Cell Cycle, Layne Weatherford

Wayne State University Dissertations

Mec1 is a protein kinase in S. cerevisiae that is critical for the DNA damage checkpoint response, and is the yeast orthologue of the human ATR protein. Cancer cells rely on ATR to arrest the cell cycle and allow sufficient time to repair DNA damage before proceeding through the cell cycle, and ATR inhibitors have been developed as possible anti-cancer agents. DBF4 is the regulatory subunit of DBF4-dependent kinase (DDK) that regulates initiation of DNA replication and is overexpressed in a number of different cancer types. To better understand ATR and DBF4 function, we took advantage of yeast genetics to …

Effective Drug Treatment Induces Drug Resistance Through Rapid Genome Alteration-Mediated Cancer Evolution, Steven Horne

Wayne State University Dissertations

The central paradox associated with current cancer therapeutic strategies is initially effective treatment, which eliminates a high tumor cell count, consistently results in successful drug resistance. Mathematical and evolutionary modeling have previously suggested that therapeutic intervention could provide selective pressure for the expansion of resistant variants. Drug-related stress has been associated with genome chaos, a common phenomenon in cancer characterized as rapid, stochastic genomic fragmentation and reorganization. Since cancer represents an evolutionary process, analysis within the context of genome-mediated cancer evolution can shed light on this key problem of therapeutics. We propose that genomic change is a general response to …

An Analysis Of The Interaction Between Sin3 And Methionine Metabolism In Drosophila, Mengying Liu

Wayne State University Dissertations

Chromatin modification and cellular metabolism are tightly connected. The mechanism for this cross-talk, however, remains incompletely understood. SIN3 controls histone acetylation through association with the histone deacetylase RPD3. In this study, my major goal is to explore the mechanism of how SIN3 regulates cellular metabolism.

Methionine metabolism generates the major methyl donor S-adenosylmethionine (SAM) for histone methylation. In collaboration with others, I report that reduced levels of some enzymes involved in methionine metabolism and histone demethylases lead to lethality, as well as wing development and cell proliferation defects in Drosophila melanogaster. Additionally, disruption of methionine metabolism can directly affect histone …

Fuzzy Unheritance: A Novel Form Of Somatic Cell Inheritance That Regulates Cell Population Heterogeneity, Batoul Abdallah

Wayne State University Dissertations

Multi-level heterogeneity is a characteristic feature of cancer cell populations. However, how a cell population regulates and maintains its cell population heterogeneity is not well understood. Based on conventional theories of genetic inheritance, cell division is precise, where a daughter cell inherits an identical karyotype from its mother cell. Therefore, errors that are generated during cell division occur at low frequencies that take prolonged time periods to accumulate. However, the overwhelming heterogeneity found in unstable cancers is largely inconsistent with current models of genetic inheritance. In order to determine the mechanism of how heterogeneity is regulated, the pattern of inherited …

A Novel Role For Repetitive Sequences In Recognition Of The Drosophila Melanogaster X Chromosome, Sonal Suresh Joshi

Wayne State University Dissertations

In humans and fruit flies, males have one X chromosome while females have two. This imbalance in gene dosage is potentially lethal, and the process of dosage compensation corrects it. The MSL (Male Specific Lethal) complex, which is composed of five proteins and one of two functionally redundant long non-coding roX (RNA on the X) RNAs, brings about dosage compensation in Drosophila melanogaster. In fruit fly dosage compensation, all the genes on the single male X chromosome are upregulated approximately twofold, via chromatin modifications, to equalize gene dosage with the two X chromosomes of females. This process calls for highly …

Novel Regulatory Mechanisms Of Inositol Biosynthesis In Saccharomyces Cerevisiae And Mammalian Cells, And Implications For The Mechanism Underlying Vpa-Induced Glucose 6-Phosphate Depletion, Wenxi Yu

Wayne State University Dissertations

Myo-inositol is the precursor of all inositol containing molecules, including inositol phosphates, phosphoinositides and glycosylphosphatidylinositols, which are signaling molecules involved in many critical cellular functions. Perturbation of inositol metabolism has been linked to neurological disorders. Although several widely-used anticonvulsants and mood-stabilizing drugs have been shown to exert inositol depletion effects, the mechanisms of action of the drugs and the role of inositol in these diseases are not understood. Elucidation of the molecular control of inositol synthesis will shed light on the pathologies of inositol related illnesses.

In Saccharomyces cerevisiae, deletion of the four glycogen synthase kinase-3 genes, MCK1, MRK1, MDS1, …

Identification Of Lead-Sensitive Expression And Splicing Quantitative Trait Loci In Drosophila Melanogaster By Analysis Of Rna-Seq Data, Wen Qu

Wayne State University Dissertations

Lead exposure has long been one of the most important topics in global public health since it is a potent developmental neurotoxin. Here, we conducted an expression QTL (eQTLs) analysis, which is genome-wide association analysis of genetic variants with differential gene expression, in the male heads of 79 Drosophila melanogaster recombinant inbred lines originally from eight parental strains in the presence or absence of developmental exposure to 250 µM lead acetate. The aim was to study the effects of lead exposure on gene expression and identify the lead-responsive genes. After detecting 1,536 cis-eQTLs and 952 trans-eQTLs (1000 permutation threshold at …

Neuronal Insult Either By Exposure To Lead Or By Direct Neuronal Damage Cause Genome-Wide Changes In Dna Methylation And Histone 3 Lysine 36 Trimethylation, Arko Sen

Wayne State University Dissertations

Prenatal and postnatal exposure to pervasive neuro-toxicants such as Lead (Pb) has been reported to causes extensive and diverse changes in the epigenetic profile. Among epigenetic modification, DNA methylation (5mC) is perhaps the most widely studied and has been proposed to be potential early biomarkers for Pb toxicity. Several studies have demonstrated the association between Pb-exposure and 5mC. However most of these studies are restricted to looking at a specific set of target genes or repetitive elements. Therefore, one of the main objectives of our study was to use an unbiased genome-wide approach to look at Pb-exposure associated changes in …

Modeling The Mechanism Underlying Environmental And Genetic Determinants Of Gene Expression And Complex Traits, Gregory Alan Moyerbrailean

Wayne State University Dissertations

Advances in next-generation sequencing technologies and functional genomics strategies have allowed researchers to identify both common and rare genetic variation, to deeply profile gene expression, and even to determine regions of active gene transcription.

While these technologies and strategies have contributed greatly to our understanding of complex traits and diseases, there are many biological questions and analytical issues to be addressed.

Genome-wide association studies (GWAS) have successfully identified large numbers of genetic variants associated with complex traits and diseases. However, in many cases the mechanistic link between the phenotype and associated variant remains unclear. This may be because most variants …

Functional Analysis Of A Highly Conserved Cyclin, Cyclin Y, In Drosophila Melanogaster, Nermin Gerges

Wayne State University Dissertations

Cyclin Y is a highly conserved member of the Cyclin superfamily of proteins. In Drosophila the Cyclin Y gene (CycY) is required for progression through several stages of development but the specific pathways that Cyclin Y belongs to and that account for its requirement are not known. Studies in human and Drosophila cell lines have shown that membrane-localized Cyclin Y is required for phosphorylation of the wingless/Wnt co-receptor, arrow/LRP6, and for full activation of the canonical wingless/Wnt pathway. CycY null Drosophila, however, do not phenocopy loss-of-function mutations in canonical wingless pathway genes, suggesting that Cyclin Y may have additional roles …

Drosophila Cyclin J And The Somatic Pirna Pathway Cooperate To Regulate Germline Stem Cells, Paul Michael Albosta

Wayne State University Dissertations

Cyclin J (CycJ) is a highly conserved cyclin that is uniquely expressed specifically in ovaries in Drosophila. Deletion of the genomic region containing CycJ and adjacent genes resulted in a genetic interaction with neighboring piRNA pathway gene, armitage (armi). Here I assessed oogenesis in CycJ null in the presence or absence of mutations in armi or other piRNA pathway genes. Although CycJ null flies had decreased egg laying and hatching rates, ovaries appeared normal indicating that CycJ is dispensable for oogenesis under normal conditions. Further double mutant analysis of CycJ and neighbor armi, as well as two other piRNA pathway …

The Role Of Crebh In Hepatic Energy Regulation Under Metabolic Stress, Roberto Mendez

Wayne State University Dissertations

Lipid metabolism is tightly regulated by nuclear receptors, transcription factors, and cellular enzymes in response to nutritional, hormonal, and stress signals. Hepatocyte specific, cyclic AMP responsive element-binding protein (CREBH) is a transcription factor that is preferentially expressed in the liver and localized in the endoplasmic reticulum (ER) membrane. CREBH is known to be activated by ER stress, inflammatory stimuli, and metabolic signals to regulate hepatic acute-phase response, lipid metabolism, and glucose metabolism. In my thesis research, I have characterized the roles and mechanisms of CREBH in these functions, as well as the overall phenotype of CrebH-null mice. I demonstrated that …

Crebh, A Novel Liver Clock Keeper For Energy Metabolism, Ze Zheng

Wayne State University Dissertations

Circadian rhythms play crucial roles in orchestrating diverse physiological processes that are critical for health and disease. Cyclic AMP responsive element binding protein 3-like 3 (CREB3L3, also known as CREBH) is a liver-enriched, endoplasmic reticulum (ER)-tethered transcription factor known to regulate hepatic acute-phase response and energy homeostasis under stress conditions. Here, we demonstrate that CREBH is regulated by the circadian clock and functions as a diurnal regulator of hepatic lipid and glucose metabolism. CREBH is required to maintain circadian profiles of blood triglycerides, fatty acids, and glucose as well as hepatic glycogen storage. CREBH rhythmically regulates expression levels and amplitudes …

A Protective Role Of Autophagy In A Drosophila Model Of Friedreich's Ataxia (Frda), Luan Wang

Wayne State University Dissertations

Friedreich’s ataxia (FRDA) is an inherited autosomal recessive neurodegenerative disease. It affects 1 in every 50,000 people in central Europe and North America. FRDA is caused by deficiency of Frataxin, an essential mitochondrial iron chaperone protein, and the associated oxidative stress damages. Autophagy, a housekeeping process responsible for the bulk degradation and turnover of long half-life proteins and organelles, is featured by the formation of double-membrane vacuoles and lysosomal degradation. Previous researches indicate that Danon’s disease, the inherited neural disorder disease that shares similar symptoms with FRDA, is due to the malfunction of autophagy. Based on this, we raise the …

The Mechanism Of Regulation Of Autosomal Heterochromatic Genes In Drosophila Melanogaster Males By Rox Rna And Msl Proteins, Satya Kiran Koya

Wayne State University Dissertations

In humans and flies, males and females have different set of sex chromosomes contributing to different levels of X-linked gene expression. To equalize X-linked gene dosage between sexes, both humans and flies developed independent strategies which are called dosage compensation. Human females randomly inactivate one of their X chromosome into barr body and Drosophila males up regulate their single X chromosome two fold. Both strategies equalize of X linked gene dose between sexes.

In Drosophila, dosage compensation is brought about by the ribonucleoprotein Male Specific Lethal (MSL) complex that binds hundreds of sites along the X chromosome and modifies …

Characterization And Identification Of Novel Regulators Of The Synthesis Of Phospholipids, Cunqi Ye

Wayne State University Dissertations

Phospholipids are the most abundant lipids in cell membranes. The synthesis of phospholipids is crucial for cellular membrane biogenesis and nearly all aspects of cellular processes. Understanding the regulation of synthesis of phospholipids is beneficial to our fundamental knowledge of cell biology as well as human health.

Regulation of the synthesis of phospholipids is intensively studied in the yeast S. cerevisiae. Most notably, the synthesis of phospholipids is coordinated with the synthesis of inositol, a precursor of inositol-containing lipids, by controlling expression of the genes encoding phospholipid biosynthetic enzymes. In addition to this well-characterized regulatory circuit controlled by the …

Linking Molecular, Electrical And Anatomical Properties Of Human Epileptic Brain, Shruti Bagla

Wayne State University Dissertations

Epilepsy is a common neurological disorder of recurrent unprovoked seizures. It affects almost 1% of the world population. Although there is a wide range of anti-epileptic drugs (AEDs) available, they only treat the seizure symptoms and do not cure the disease itself. The poor role of AEDs can be attributed to the lack of knowledge of exact mechanisms and networks that produce epileptic activities in the neocortex. At present, the best cure for epilepsy is surgical removal of electrically localized epileptic brain tissue. Surgically removed brain tissue presents an excellent opportunity to discover the molecular and cellular basis of human …

Sex And Heterochromatin: An Investigation Of Sexual Dimorphism In Drosophila Melanogaster, Manasi S. Apte

Wayne State University Dissertations

Over 30% of Drosophila genome is assembled into heterochromatin. Heterochromatin is relatively gene poor, transcriptionally less active and remains condensed during interphase. Previous studies established that roX RNA and some of the Male Specific Lethal (MSL) proteins, all components of the dosage compensation complex, are required for full expression of autosomal heterochromatic genes in male flies but not in females. This was surprising since heterochromatin is generally not thought to be sexually dimorphic. The genetic basis for the regulation of sex-specific heterochromatin was completely unknown.

To determine if roX RNAs localize directly at the heterochromatic regions that they regulate, I …

The Drosophila Interactions Database: Integrating The Interactome And Transcriptome, Thilakam Murali

Wayne State University Dissertations

In this thesis I describe the integration of heterogeneous interaction data for Drosophila into DroID, the Drosophilainteractions database, making it a one-stop public resource for interaction data. I have also made it possible to filter the interaction data using gene expression data to generate context-relevant networks making DroID a one-of-a kind resource for biologists. In the two years since the upgraded DroID has been available, several studies have used the heterogeneous interaction data in DroID to advance our understanding of Drosophila biology thus validating the need for such a resource for biologists. In addition to this, I have identified …

Investigation Of X Chromosome Recognition: The Role Of Small Rna In Drosophila Dosage Compensation, Debashish Unnikrishnan Menon

Wayne State University Dissertations

In humans and flies, females have two X chromosomes but males have one X chromosome and one Y chromosome. This leads to a fatal imbalance in X-linked gene expression in one sex. In mammals and in the fruit fly Drosophila, modulation of X chromosome expression is critical for survival. This process is termed dosage compensation. Flies increase expression from the male X chromosome two-fold. This is achieved by the Male Specific Lethal (MSL) complex, which consists of two large, non-coding RNA on the X transcripts (roX1 and roX2) and five proteins. The roX RNAs have a critical …

The Role Of Cardiolipin In Iron Homeostasis And Glutathione Metabolism, Vinay A. Patil

Wayne State University Dissertations

Cardiolipin (CL) is the signature phospholipid of mitochondrial membranes, where it is synthesized locally and plays a critical role in mitochondrial bioenergetic functions. Inside the mitochondria, CL is a critical target of mitochondrial generated reactive oxygen species (ROS) and regulates signaling events related to apoptosis and aging. CL deficiency causes perturbation of signaling pathways outside the mitochondria, including the PKC-Slt2 cell integrity pathway and the high osmolarity glycerol (HOG) pathway, and is a key player in the cross-talk between the mitochondria and the vacuole. The importance of CL in human health is underscored by the observation that perturbation of CL …