Genetics and Genomics Commons^™

Examining The Roles Of The Conserved Mrna Deadenylase Complex On Drosophila Neuronal Structures, Megan Mccaughey, Scott Barbee

DU Undergraduate Research Journal Archive

The most common cause of inherited mental deficiency and monogenetic cause of autism is Fragile X Syndrome (FXS). There is little known about the origins of this disease which will be investigated in the present study. The series of experiments conducted examined the potential role of mRNA deadenylation proteins as contributing factors to the pathogenesis of FXS using Drosophila melanogaster as a model organism. One of the main complexes involved in deadenylation is the CNOT complex, which is comprised of many proteins, including POP2, TWIN, and NOT3. Each protein plays a unique role within the CNOT complex. This goal of …

The Roles Of Polar Cell Extensions In Drosophila Micropyle Formation, Bradford Hull

Theses and Dissertations--Biology

The Drosophila micropyle is a conserved formation utilized to allow sperm passage past the robust eggshell structure for fertilization. Micropyle formation follows a unique acellular tubulogenesis method where it is secreted and shaped by specialized follicle cells including the border cells and polar cells. In late oogenesis, the polar cells form extensions that are necessary to create the micropyle pore through which sperm enters. Previous work established that polar cell extension presence is required for micropyle pore formation. We investigated temporal requirements of extensions throughout chorion deposition and found extensions are required during the beginning and middle of choriogenesis, but …

Mef2-Bound Genes May Influence Ethanol Sedation In Drosophila Melanogaster, Katlyn M. Myers

Theses and Dissertations

Alcohol Use Disorder (AUD) is a global health issue that affects millions of people every year. This disorder has serious negative mental and physical consequences. Currently, treatment options for this disorder are largely limited to psychological therapy, with very few medications available to treat it. Being able to identify the environmental and genetic components that influence AUD can help improve diagnosis and treatment options. Previous studies in humans have shown a link between initial sensitivity and risk for alcohol abuse. Our laboratory uses Drosophila melanogaster as a model to study the genetic and environmental components of alcohol-related behaviors. Previous lab …

Functional Importance Of Lipin Phosphorylation, Stephanie Elizabeth Hood

Graduate Theses and Dissertations

Highly conserved throughout evolution, lipins are dual functioning proteins found from yeast to humans. Functioning in the cytoplasm as phosphatidate phosphatase enzymes (PAP), lipins produce diacylglycerol that serves as a precursor for neutral fats and membrane phospholipids. Alternatively, nuclear lipins are responsible for the regulation of metabolic genes. Interestingly, both the mammalian lipin 1 paralog and the single Drosophila Lipin ortholog are highly phosphorylated proteins. Target of rapamycin (TOR) has previously been identified as one of the kinases that controls the subcellular localization of both lipin 1 and Drosophila Lipin. However, other serine and threonine kinases are predicted to be …

Dietary Restriction Enhances Circadian Amplitude And Delays Visual Decline By A Clock-Driven Increase In Phototransduction, Geoff Meyerhof

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Aging is accompanied by a progressive loss of circadian rhythms. Lifespan-extending dietary paradigms such as dietary restriction (DR) enhance circadian amplitude and appear to extend lifespan in a clock-dependent fashion. However, the mechanisms by which DR amplifies circadian rhythms and why circadian rhythms decline with age have yet to be fully elucidated. Here we find that DR amplifies circadian amplitude by enhancing light sensitivity in the eye. We performed a circadian mRNA microarray in flies (Drosophila melanogaster) reared on DR or a high nutrient diet and found that DR increases the number of circadian transcripts and selectively amplifies the …

Glial Cell Mechanisms Regulate Alcohol Sedation In Drosophila Melanogaster, Kristen M. Lee

Theses and Dissertations

Approximately 16 million people in America are diagnosed with Alcohol Use Disorder (AUD) but no efficacious medical treatments exist. Alcohol-related behaviors can be studied in model organisms, and changes in these behaviors can be correlated with either (i) a risk for alcohol dependence or (ii) a symptom/feature of AUD itself. Although AUD is a disease of the central nervous system, a majority of research has focused on the neuronal underpinnings, leaving glial contributions largely undescribed. We used Drosophila melanogaster (fruit fly) to identify genes whose expression in glia regulates alcohol sedation. Mammals and Drosophila have conserved behavioral responses to alcohol …

Genetic And Environmental Factors Influence Drosophila Ethanol Sedation, Rebecca E. Schmitt

Theses and Dissertations

Alcohol use disorder is a global health issue that affects a significant portion of the population, with affects including both negative mental and physical consequences. Currently, there are few treatment options available to those who suffer from alcohol use disorder, alcohol abuse, or alcohol dependence. Identifying candidate genes or environmental influences would therefore improve the means for possible treatments or identification of those people at risk for alcohol use disorder. Previous studies in humans have demonstrated an inverse association between initial sensitivity and risk for alcohol abuse. This connection allows investigators, and our laboratory, to investigate genetic and environmental factors …

An Expanded Toolkit For Gene Tagging Based On Mimic And Scarless Crispr Tagging In, David Li-Kroeger, Oguz Kanca, Pei-Tseng Lee, Sierra Cowan, Michael T Lee, Manish Jaiswal, Jose Luis Salazar, Yuchun He, Zhongyuan Zuo, Hugo J Bellen

Faculty, Staff and Students Publications

We generated two new genetic tools to efficiently tag genes in Drosophila. The first, Double Header (DH) utilizes intronic MiMIC/CRIMIC insertions to generate artificial exons for GFP mediated protein trapping or T2A-GAL4 gene trapping in vivo based on Cre recombinase to avoid embryo injections. DH significantly increases integration efficiency compared to previous strategies and faithfully reports the expression pattern of genes and proteins. The second technique targets genes lacking coding introns using a two-step cassette exchange. First, we replace the endogenous gene with an excisable compact dominant marker using CRISPR making a null allele. Second, the insertion is replaced …

Analysis Of Chromatin Interactions Of Beaf-Associated Promoters Using 4c, Shraddha Shrestha

LSU Doctoral Dissertations

A high degree of chromosome compaction is needed to fit nearly 2 meters of DNA inside a human nucleus of around 10 µm diameter. Correct chromatin folding is crucial to facilitate important nuclear functions such as transcription, DNA replication and DNA repair. Nuclei contain a variety of proteins, many of which help regulate chromatin structure and function. The mechanisms by which these proteins work are diverse and complicated. Here, we study the chromatin interactions of Boundary Element Associated Factor (BEAF) associated sites to gain insight into eukaryotic genome organization. We used circular chromosome conformation capture (4C) technology to detect genome-wide …

Disruption Of Rna Metabolism By Zika Virus, Maggie Lea Dickerson

Honors Theses

Flaviviruses are positive, single-stranded, enveloped RNA viruses that are a part of the family, Flaviviridae. West Nile virus, Dengue, Zika virus and more are a part of this family. Mosquitoes are the vectors for these viruses. In order for the virus to infect mosquitoes, it must evade the RNA interference (RNAi), which is the major antiviral immune mechanism of insects. One study found the 3’ untranslated region (UTR) of the West Nile virus that inhibited the RNAi (GP et al. 2016). The goal of this study is to investigate if the 3’ and 5’ UTR region of the Zika virus …

Evolutionary Conservation Of Midline Repulsion By Robo Family Receptors In Flies And Mice, Allison Loy

Biological Sciences Undergraduate Honors Theses

As the nervous system develops in animal embryos, neuronal axons are guided to their synaptic targets by extra cellular cues that signal through axon guidance receptors expressed on the surface of the axon. In animals with bilateral symmetry, one of the important decisions made by nearly every axon in the embryonic nervous system is whether to stay on its own side of the body, or to cross the midline and connect to cells on the opposite side. The Roundabout (Robo) family is an evolutionarily conserved group of axon guidance receptors that regulate midline crossing in a wide range of animal …

Studies Of Norspermidine Uptake In Drosophila Suggest The Existence Of Multiple Polyamine Transport Pathways, Michael Dieffenbach

Honors Undergraduate Theses

Polyamines are a class of essential nutrients involved in many basic cellular processes such as gene expression, cell proliferation, and apoptosis. Without polyamines, cell growth is delayed or halted. Cancerous cells require an abundance of polyamines through a combination of synthesis and transport from the extracellular environment. An FDA-approved drug, D,L-α-difluoromethylornithine (DFMO), blocks polyamine synthesis but is ineffective at inhibiting cell growth due to polyamine transport. Thus, there is a need to develop drugs that inhibit polyamine transport to use in combination with DFMO. Surprisingly, little is known about the polyamine transport system in humans and other eukaryotes. Understanding the …

Jak/Stat Signaling Regulates Gametogenesis And Age-Related Reproductive Maintenance, Michelle Suzanne Giedt

Theses and Dissertations--Biology

Cell signaling is central to integration of internal and external cues that regulate development and homeostasis. Most development is thought of as pre-adult, but limited developmental processes occur in adults. Gametogenesis incorporates elements of both these facets, with a distinct developmental plan for gamete synthesis which is regulated by integration of homeostatic inputs such as nutrient status, and environmental cues. Signaling pathways integrate and transduce information from these cues to evoke a response. A decline in homeostasis and subsequent cues occurs over time, in the case of reproductive tissues leading to a progressive loss of fertility. The Janus Kinase and …

A Combined Computational Strategy Of Sequence And Structural Analysis Predicts The Existence Of A Functional Eicosanoid Pathway In Drosophila Melanogaster, Michael Scarpati

Dissertations, Theses, and Capstone Projects

With increased understanding of their roles in signal transduction and metabolism, eicosanoids have emerged as important players in human health and disease. Mammalian prostanoids and related lipid mediators perform varied functions in different tissues and organs. Synthesized through the oxygenation of C20 polyunsaturated fatty acids, mammalian eicosanoids are both pro- and anti-inflammatory. The physiological contexts in which eicosanoid family members act at the cellular level are not well understood. In this study, we examined whether the genome of Drosophila melanogaster, a powerful model for innate immunity and inflammation, codes for the enzymes required for eicosanoid biosynthesis. We report the …

Retrotransposons Are The Major Contributors To The Expansion Of The Drosophila Ananassae Muller F Element, Wilson Leung, Martin G. Burg, Spencer M. Batten, Lindsay M. Corbeill, Erica Enoch, Jesse J. Ensign, Mary E. Franks, Breanna Haiker, Judith A. Ingles, Lyndsay D. Kirkland, Josha M. Lorenz-Guertin, Jordan Matthews, Cody M. Mittig, Nicholaus Monsma, Katherine J. Olson, Guillermo Perez-Aragon, Alen Ramic, Jordan R. Ramirez, Christopher Scheiber, Patrick A. Schneider, Devon E. Schultz, Matthew Simon, Eric Spencer, Adam C. Wernette, Maxine E. Wykle, Elizabeth Zavala-Arellano, Mitchell J. Mcdonald, Kristine Ostby, Peter Wendland

Peer Reviewed Articles

The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) …

Retrotransposons Are The Major Contributors To The Expansion Of The Drosophila Ananassae Muller F Element, Wilson Leung, Gerard Mcneil

Publications and Research

The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (.18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors …

Examining The Neuronal Dopaminergic Pathway Underlying Sleep Behavior And Related Dopamine Sleep Disorders, Mary Beth Putz

Undergraduate Honors Theses

The human brain is an extremely complex organ with approximately 100 billion different neurons that are constantly sending and receiving messages. These messages are sent using the chemical messengers of the brain: neurotransmitters and neuromodulators. Mechanisms of neural control of sleep are substantially conserved across species. Evidence from multiple animal models including flies, zebrafish, and mice shows that the arousal, or wake phase, is regulated by conserved neuromodulators such as dopamine, norepinephrine, and serotonin. Since these neurotransmitter systems are distributed throughout the brain and sub-serve many functions in addition to sleep, the precise circuit mechanisms by which these neurotransmitters regulate …

A Genetic Analysis Of Nuclear Functions Of The Lipin Protein In Drosophila Melanogaster, Xeniya Rudolf

Graduate Theses and Dissertations

Lipins are a family of proteins that have critical functions in the control of fat storage and energy homeostasis. Biochemically, lipins have two functions. They provide an enzymatic activity (phosphatidate phosphatase or PAP activity) in the glycerol-3 phosphate pathway that leads to the production of storage fats (triacylglycerols). In addition, they play a role in the regulation of genes in the cell nucleus as transcriptional co-regulators. The PAP activity of lipins has been widely studied in a number of organisms. However, the transcriptional co-regulator function is not as well described in the literature. The transcriptional function of lipins depends on …

Sumo Regulates The Activity Of Smoothened And Costal-2 In Drosophila Hedgehog Signaling, Jie Zhang, Yajuan Liu, Kai Jiang, Jianhang Jia

Markey Cancer Center Faculty Publications

In Hedgehog (Hh) signaling, the GPCR-family protein Smoothened (Smo) acts as a signal transducer that is regulated by phosphorylation and ubiquitination, which ultimately change the cell surface accumulation of Smo. However, it is not clear whether Smo is regulated by other post-translational modifications, such as sumoylation. Here, we demonstrate that knockdown of the small ubiquitin-related modifier (SUMO) pathway components Ubc9 (a SUMO-conjugating enzyme E2), PIAS (a SUMO-protein ligase E3), and Smt3 (the SUMO isoform in Drosophila) by RNAi prevents Smo accumulation and alters Smo activity in the wing. We further show that Hh-induced-sumoylation stabilizes Smo, whereas desumoylation by Ulp1 …

Functional Significance Of Branch Points In Mirtrons, Britton A. Strickland

Honors Theses

MicroRNAs are a heterogeneous group of small regulatory RNAs generated by many pathways. Mirtrons (miR) are a class of microRNAs produced by splicing, and some mirtrons contain a 3’ tail located downstream from the self-complementary hairpin. During RNA splicing, a loop-like “lariat” intermediate structure is created when the 5’ end of the RNA is attached to an adenine called the branch point. The goal of this project is to uncover the contribution of branch point location to the processing of tailed mirtrons into functional gene regulators. This project approaches this issue from two directions. First, branch points were identified by …

Characterization Of Vesicular Monoamine Transporter 2 And Its Role In Parkinson's Disease Pathogenesis Using Drosophila, Antonio Joel Tito Jr., Sheng Zhang

Dissertations and Theses (Open Access)

Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the selective loss of the dopaminergic neurons in the Substantia nigra pars compacta region of the brain. PD is also the most common neurodegenerative disorder and the second most common movement disorder. PD patients exhibit the cardinal symptoms, including tremor of the extremities, rigidity, slowness of movement, and postural instability, after 70-80% of DA neurons degenerate. It is, therefore, imperative to elucidate the underlying mechanisms involved in the selective degeneration of DA neurons. Although increasing numbers of PD genes have been identified, why these largely widely expressed genes induce …

Reverse Genetic Screening Of Innexin Gap Junction Proteins In Drosophila Neurons, Shannon P. Fox

Senior Honors Projects, 2010-2019

The reflexive response and perception of pain (nociception) is an evolutionarily conserved process in animals. Pain can be a major health concern and current treatments often prove insufficient, especially in regards to chronic pain. Greater understanding of the molecular processes underlying pain sensation could lead to new and more effective treatments. The aim of this study is to investigate the molecular mechanisms of cold nociception in Drosophila melanogaster. A specific subset of peripheral sensory neurons (Class III dendritic arborization (da) neurons), are implicated in Drosophila larvae’s response to noxious cold.

Previous literature has associated a family of gap junction protein, …

Axonal Transport And Life Cycle Of Mitochondria In Parkinson's Disease Model, Hyun Sung

Open Access Dissertations

In neurons, normal distribution and selective removal of mitochondria are essential for preserving compartmentalized cellular function. Parkin, an E3 ubiquitin ligase associated with familial Parkinson’s disease, has been implicated in mitochondrial dynamics and removal. However, it is not clear how Parkin plays a role in mitochondrial turnover in vivo, and whether the mature neurons possess a compartmentalized Parkin-dependent mitochondrial life cycle. Using the live Drosophila nervous system, here, I investigate the involvement of Parkin in mitochondrial dynamics; organelle distribution, morphology and removal. Parkin deficient animals displayed less number of axonal mitochondria without disturbing organelle motility behaviors, morphology and metabolic state. …

Pi(4)P Promotes Phosphorylation And Conformational Change Of Smoothened Through Interaction With Its C-Terminal Tail, Kai Jiang, Yajuan Liu, Junkai Fan, Jie Zhang, Xiang-An Li, B. Mark Evers, Haining Zhu, Jianhang Jia

Markey Cancer Center Faculty Publications

In Hedgehog (Hh) signaling, binding of Hh to the Patched-Interference Hh (Ptc-Ihog) receptor complex relieves Ptc inhibition on Smoothened (Smo). A longstanding question is how Ptc inhibits Smo and how such inhibition is relieved by Hh stimulation. In this study, we found that Hh elevates production of phosphatidylinositol 4-phosphate (PI(4)P). Increased levels of PI(4)P promote, whereas decreased levels of PI(4)P inhibit, Hh signaling activity. We further found that PI(4)P directly binds Smo through an arginine motif, which then triggers Smo phosphorylation and activation. Moreover, we identified the pleckstrin homology (PH) domain of G protein-coupled receptor kinase 2 (Gprk2) as an …

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 …

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 …

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 …

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 …

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 …

Suppression Of Neurodegenerative Symptoms Via Suppressor Of Levy Mutation In Drosophila Melanogaster, William Kaputa

Forensic Science Theses

Mutation of the levy gene on chromosome 2 of Drosophila melanogaster has previously been shown to cause temperature-induced paralysis and neurodegeneration. The Suppressor of levy mutation, Su(levy), also on chromosome 2, modulates the effects of the levy mutation and partly rescues the wild-type phenotype. The goal of this research was to determine if Su(levy) mutation alleviates the effects of neurodegeneration caused by mutations associated with Alzheimer’s and Parkinson’s diseases in humans. The mutant genes used were hLRRK2, α-Synuclein, DJ1-α, Pink, Parkin, and Aβ-42. To determine this, flies carrying the above-mentioned mutant genes were …