Genetics Commons^™

Neural Rrp6 Depletion Drives Circrna Accumulation And Motor Impairment In Drosophila Melanogaster Neurons, Joseph Serio

Honors Theses

Circular RNAs (circRNAs) are a class of ubiquitous eukaryotic RNAs created by back splicing. These noncoding RNAs can modulate gene expression and are implicated in aging and neurodegenerative diseases. To limit the contribution of circRNAs to aging and pathobiology, it is essential to understand how turnover of these molecules is regulated, as it is not clear which enzymes are chiefly responsible for degrading circRNAs in neurons. This study evaluates the roles of ribonucleases potentially involved in neural circRNA turnover using the model fly Drosophila melanogaster. A mifepristone-activated GAL4/UAS GeneSwitch expressed RNAi transgenes and inactivated the ribonucleases. Flies were evaluated on …

The Role Of Elongin B In Drosophila Melanogaster Muscle Development, Madelyne Dayan

Student Theses and Dissertations

Muscle atrophy is a result of a number of muscle diseases, as well as aging, disuse, and infections. Muscles weakened in these ways exhibit a characteristic decrease in size, strength, and mobility. The similarities between muscle in humans and Drosophila allow for direct comparisons to be made in vertebrates from studying muscle in Drosophila. Differential gene expression has been shown to play an important role in embryonic muscle development in Drosophila melanogaster. A previous study identified Elongin B (EloB) to be involved in somatic muscle morphogenesis in Drosophila, with mutant embryos displaying severe muscle defects, including thin, mis-attached, and missing …

Investigating Genetic Regulators Of Crystal Cell Development In Drosophila Melanogaster, Andrea Feria, Nyla Walbrook, Anisa Turaeva, Rebecca Spokony

Publications and Research

Crystal cells, a subset of Drosophila melanogaster hemocytes, are important for melanization, a crucial immune response. While the genetic regulation of crystal cell develop remains incompletely understood, this study investigates the functions of five candidate genes: ACXB, ACXA, Gp210, CG4390, and Cyp4s3; identidied through previous genome-wide association studies. Using the Gal4/UAS system along with RNA interference (RNAi), we exclusively knocked down each gene in third instar larvae and quantified crystal cell populations following heat shock-induced melanization. Our results imply that the knockdown of ACXB and ACXA significantly increased crystal cell counts in both sexes, suggesting these genes either act as …

Failure To Mate Enhances Investment In Behaviors That May Promote Mating Reward And Impairs The Ability To Cope With Stressors Via A Subpopulation Of Neuropeptide F Receptor Neurons, Julia Ryvkin, Liora Omesi, Yong-Kyu Kim, Mali Levi, Hadar Pozeilov, Lital Barak-Buchris, Bella Agranovich, Ifat Abramovich, Eyal Gottlieb, Avi Jacob, Dick R Nässel, Ulrike Heberlein, Galit Shohat-Ophir

Faculty, Staff and Student Publications

Living in dynamic environments such as the social domain, where interaction with others determines the reproductive success of individuals, requires the ability to recognize opportunities to obtain natural rewards and cope with challenges that are associated with achieving them. As such, actions that promote survival and reproduction are reinforced by the brain reward system, whereas coping with the challenges associated with obtaining these rewards is mediated by stress-response pathways, the activation of which can impair health and shorten lifespan. While much research has been devoted to understanding mechanisms underlying the way by which natural rewards are processed by the reward …

Localization Of Ctg-Repeat-Containing Transgenes In Drosophila Melanogaster Myotonic Dystrophy Models, Andrea Waltrip

Departmental Honors & Graduate Capstone Projects

Myotonic Dystrophy Type 1, DM1, is a multi-systemic muscle wasting disorder that results from expression of expanded CTG repeats in the DMPK gene in humans. Three transgenic Drosophila melanogaster lines have been created containing 60, 250, or 480 CTG repeats to model DM1. The transgenic repeats are expressed using the GAL4/UAS system. Expression of long-repeat transgenes ((CTG)₂₅₀ and i(CTG)₄₈₀) produces phenotypes consistent with DM1, relative to control lines ((CTG)₆₀). The precise chromosomal location of insertion of the transgenes has not been reported. We used classical genetic approaches to localize CTG-repeat transgene insertion to a specific …

Biallelic Variants In Ogdh Encoding Oxoglutarate Dehydrogenase Lead To A Neurodevelopmental Disorder Characterized By Global Developmental Delay, Movement Disorder, And Metabolic Abnormalities, Ella F Whittle, Madison Chilian, Ehsan Ghayoor Karimiani, Helga Progri, Daniela Buhas, Melis Kose, Rebecca D Ganetzky, Mehran Beiraghi Toosi, Paria Najarzadeh Torbati, Reza Shervin Badv, Ivan Shelihan, Hui Yang, Houda Zghal Elloumi, Sukyeong Lee, Yalda Jamshidi, Alan M Pittman, Henry Houlden, Erika Ignatius, Shamima Rahman, Reza Maroofian, Wan Hee Yoon, Christopher J Carroll

Faculty, Staff and Students Publications

PURPOSE: This study aimed to establish the genetic cause of a novel autosomal recessive neurodevelopmental disorder characterized by global developmental delay, movement disorder, and metabolic abnormalities.

METHODS: We performed a detailed clinical characterization of 4 unrelated individuals from consanguineous families with a neurodevelopmental disorder. We used exome sequencing or targeted-exome sequencing, cosegregation, in silico protein modeling, and functional analyses of variants in HEK293 cells and Drosophila melanogaster, as well as in proband-derived fibroblast cells.

RESULTS: In the 4 individuals, we identified 3 novel homozygous variants in oxoglutarate dehydrogenase (OGDH) (NM_002541.3), which encodes a subunit of the tricarboxylic acid cycle enzyme …

Vps54 Regulates Lifespan And Locomotor Behavior In Adult Drosophila Melanogaster, Emily C. Wilkinson, Emily L. Starke, Scott A. Barbee

Biological Sciences: Faculty Scholarship

Vps54 is an integral subunit of the Golgi-associated retrograde protein (GARP) complex, which is involved in tethering endosome-derived vesicles to the trans-Golgi network (TGN). A destabilizing missense mutation in Vps54 causes the age-progressive motor neuron (MN) degeneration, muscle weakness, and muscle atrophy observed in the wobbler mouse, an established animal model for human MN disease. It is currently unclear how the disruption of Vps54, and thereby the GARP complex, leads to MN and muscle phenotypes. To develop a new tool to address this question, we have created an analogous model in Drosophila by generating novel loss-of-function alleles of the …

Mechanisms Of How Diet And Light Interact To Influence Drosophila Longevity Through The Eye, Charles H. Lau

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Previous studies in Drosophila melanogaster have established that overexposure to light damages photoreceptors and that photoreceptor degeneration contributes to shortened lifespans. However, the role of diet and circadian rhythms in the eye has not yet been elucidated. Many vital processes in the eye are regulated by circadian rhythms, and circadian misalignment has been proven as a driver of aging. In the eye, one of the most enriched circadian functions is phototransduction. Phototransduction plays a major role in the organism’s ability to detect light. Our lab has previously proven that Dietary Restrictions (DR) can play a role in amplifying circadian rhythms …

Mapping And Characterization Of Mutagen Sensitivity Genes In Drosophila Malanogaster, Alexis Nystrom

Graduate Theses

The information contained within DNA is vital to directing all biological processes. All organisms have repair mechanisms in place to repair DNA damage quickly and efficiently. Without these repair pathways, DNA can acquire harmful mutations that can compromise the survival of an organism. Studies of DNA repair in Drosophila melanogaster have focused on mutagen sensitive (mus) mutants, each of which contain a mutation that renders them incapable of performing DNA repair. Since a majority of these mus genes are unmapped, the goal of this project was to determine what genes in the Drosophila melanogaster genome are mus106 and mus108. Presence …

Examining A Functional Interaction Between Chromatin Remodeler Chd1 And Histone H1 In D. Melanogaster, Breanna Kim

Scripps Senior Theses

Chromodomain-helicase-DNA-binding-protein-1 (CHD1) is a highly conserved ATP- dependent remodeling protein. It is localized to active genes and directs nucleosome spacing, while its loss has been linked to various human diseases, such as human prostate cancer. In Drosophila, CHD1 is important for fertility and wing development, and overexpression of CHD1 leads to severe wing vein defect phenotypes. The Linker Histone H1, which is known for maintaining heterochromatin and is associated with inactive genes, had been previously identified as a possible functional partner of CHD1, though the exact nature of their interaction is unclear. I undertook a genetic approach to examining the …

Identifying Genes Downstream Of Mef2 That Influence Ethanol Sedation In Drosophila Melanogaster, Ananya Talikoti

Theses and Dissertations

Alcohol use disorder is a global public health issue that affects millions across the world. It can result in negative physical and mental health outcomes, and currently treatment options are limited and rates of relapse are high. Identifying genes that affect aspects of ethanol behaviors in model organisms, such as Drosophila melanogaster, can serve to eventually develop more robust therapeutic interventions for those experiencing alcohol dependence. Previous studies have identified a relationship between a person's initial sensitivity to alcohol and their abuse potential for the drug in later life. Therefore, we can study sedation behaviors in Drosophila melanogaster to …

Detecting The Cold: Do Innexins Function In Cold Nociception?, Rachel Barborek

Senior Honors Projects, 2010-2019

Nociception is the perception of and response to harmful stimuli. Nociception is essential for minimizing tissue damage, but aberrant nociceptive pathways can result in chronic pain. Chronic pain in the U.S. is commonly managed with wide-acting opioids, and precisely defining the components of nociceptive pathways could uncover novel targets for pain therapies. I hypothesize that the vitally quick process of nociception would utilize electrical synapses because they transmit signals between neurons more quickly than chemical synapses do. This study, therefore, aims to uncover the potential role of the eight Drosophila melanogaster gap junction proteins, the Innexins, in cold nociception. Wild …

Investigating The Role Of Free Radicals In Huntington's Disease Using Drosophila Melanogaster, Jennifer Libov

Honors Program: Senior Projects (Public)

During normal cell metabolism, reactive oxygen species (ROS) are produced as a byproduct of oxidative phosphorylation. ROS are utilized in the cell as a signaling molecule and can be maintained at healthy levels by cellular antioxidants. However, when the cell experiences oxidative stress due to environmental or genetic conditions, levels of ROS can exceed healthy levels and inhibit necessary life functions by damaging biomolecules and cellular structures. This loss of function can lead to physiological decline and neurodegeneration, such as in diseases like Alzheimer’s, amyotrophic lateral sclerosis (ALS), and, potentially, Huntington’s disease. The following experiments use the model genetic organism …

Effect Of Larval Starvation On Lipid Content Of Drosophila Melanogaster Over 15 Days, Fabian Leija, Allen Gibbs

LSAMP Poster Presentations

Starvation-resistant Drosophila melanogaster, common fruit flies, deriving from 121 generations of starvation selection, have resulted in genetically, behaviorally, and physiologically different individuals compared to non-resistant counterparts. Starvation-resistant Drosophila are more obese, containing twice as much lipids as control flies.This is a result of starvation-resistant fly larva feeding for 5 days and then entering the pupa stage while non-resistant flies only feed for 4 days.

In this experiment, we hope to answer the question of whether the starvation-resistant flies are genetically predisposed to be substantially more obese than wild populations or if it is a result of this alternate behavior …

Genetic Basis Of Larval Crystal Cell Quantity Variation In The Drosophila Genetic Reference Panel (Dgrp), Brian Tang

Student Theses and Dissertations

Crystal cells are one of three requisite hemocytes that take part in fighting infection and wound healing in Drosophila melanogaster (common fruit flies). The developmental genetics of crystal cell formation is only beginning to be discovered. To address this question, we performed a Genome-Wide Association Study (GWAS) on larval crystal cell number from 78 isolines of the Drosophila Genetic Reference Panel (DGRP) collection. The DGRP consists of naturally caught fruit flies that are inbred to near homozygosity with completely sequenced genomes. By placing the wandering third instar larvae under heatshock, a process that induces the melanization of crystal cells, …

Gene Expression Profiling In The Larval Fat Body Of Desiccation Selected Drosophila Melanogaster, Adriana Michelle Charles

UNLV Theses, Dissertations, Professional Papers, and Capstones

Drosophila melanogaster selected for resistance to desiccation (no food or water) display slower development and a higher body mass compared to fed controls due to an extended third larval instar. I hypothesize that desiccation selected D. melanogaster larvae will have a different gene expression profile compared to fed controls. Separate populations of D. melanogaster were subjected to desiccation (no food or water), starvation (no food) until 80-85% mortality, for 75 generations. mRNA from the larval fat body was collected at 88 hours, 96 hours, 112 hours and 120 hours post-hatching. Four replicate samples were used for each condition and time …

An Undergraduate Cell Biology Lab: Western Blotting To Detect Proteins From Drosophila Eye, Neha Gogia, Ankita Sarkar, Amit Singh

Biology Faculty Publications

We have developed an undergraduate laboratory to allow detection and localization of proteins in the compound eye of Drosophila melanogaster, a.k.a fruit fly. This lab was a part of the undergraduate curriculum of the cell biology laboratory course aimed to demonstrate the use of Western Blotting technique to study protein localization in the adult eye of Drosophila. Western blotting, a two-day laboratory exercise, can be used to detect the presence of proteins of interests from total protein isolated from a tissue. The first day involves isolation of proteins from the tissue and SDS-PAGE (sodium dodecyl sulfate-polyacrylamide) gel …

Real-Time Quantitative Pcr To Demonstrate Gene Expression In An Undergraduate Lab, Abijeet Singh Mehta, Amit Singh

Biology Faculty Publications

The objective of this teaching note is to develop a laboratory exercise, which allows students to get a hands-on experience of a molecular biology technique to analyze gene expression. The short duration of the biology laboratory for an undergraduate curriculum is the biggest challenge with the development of new labs. An important part of cell biology or molecular biology undergraduate curriculum is to study gene expression. There are many labs to study gene expression in qualitative manner. The commonly used reporter gene expression studies are primarily qualitative. However, there is no hands-on experience exercise to quantitatively determine gene expression. Therefore, …

Ubr3, A Novel Modulator Of Hh Signaling Affects The Degradation Of Costal-2 And Kif7 Through Poly-Ubiquitination, Tongchao Li, Junkai Fan, Bernardo Blanco-Sánchez, Nikolaos Giagtzoglou, Guang Lin, Shinya Yamamoto, Manish Jaiswal, Kuchuan Chen, Jie Zhang, Wei Wei, Michael T. Lewis, Andrew K. Groves, Monte Westerfield, Jianhang Jia, Hugo J. Bellen

Markey Cancer Center Faculty Publications

Hedgehog (Hh) signaling regulates multiple aspects of metazoan development and tissue homeostasis, and is constitutively active in numerous cancers. We identified Ubr3, an E3 ubiquitin ligase, as a novel, positive regulator of Hh signaling in Drosophila and vertebrates. Hh signaling regulates the Ubr3-mediated poly-ubiquitination and degradation of Cos2, a central component of Hh signaling. In developing Drosophila eye discs, loss of ubr3 leads to a delayed differentiation of photoreceptors and a reduction in Hh signaling. In zebrafish, loss of Ubr3 causes a decrease in Shh signaling in the developing eyes, somites, and sensory neurons. However, not all tissues that require …

The Adp-Ribose Polymerase Tankyrase Regulates Adult Intestinal Stem Cell Proliferation During Homeostasis In Drosophila, Zhenghan Wang, Ai Tian, Hassina Benchabane, Ofelia Tacchelly-Benites, Eungi Yang, Hisashi Nojima, Yashi Ahmed

Dartmouth Scholarship

Wnt/β-catenin signaling controls intestinal stem cell (ISC) proliferation, and is aberrantly activated in colorectal cancer. Inhibitors of the ADP-ribose polymerase Tankyrase (Tnks) have become lead therapeutic candidates for Wnt-driven cancers, following the recent discovery that Tnks targets Axin, a negative regulator of Wnt signaling, for proteolysis. Initial reports indicated that Tnks is important for Wnt pathway activation in cultured human cell lines. However, the requirement for Tnks in physiological settings has been less clear, as subsequent studies in mice, fish and flies suggested that Tnks was either entirely dispensable for Wnt-dependent processes in vivo, or alternatively, had tissue-specific roles. Here, …

The Role Of Rapgap1 In Sxl Activation In Drosophila Melanogaster, Katherine M. Barnes

Lewis Honors College Capstone Collection

The master switch of the sexual differentiation and dosage compensation pathway in Drosophila is the sex lethal gene, Sxl. The early promoter, SxlPe, is activated in females, resulting in female-specific splicing of later transcripts (notably the late Sxl transcript SxlPm), while inactive in males. Chromatin immunoprecipitation (ChIP) assays have previously shown association of two conventionally heterochromatin-localized proteins, HOAP and HP1, at SxlPe, and in situ hybridization as well as RT-PCR assays have confirmed a repressive role for HOAP and both repressive and activating roles for HP1. The mechanism for the activity shift of HP1 is currently unknown. Deletions in the …

The Mechanisms Of Α-Amanitin Resistance In The Fruit Fly Drosophila Melanogaster, Chelsea L. Mitchell

Dissertations, Master's Theses and Master's Reports

Insect pesticide resistance has become a costly problem in the US. To make things more problematic, resistance to one pesticide is often associated with cross-resistance to other toxins, including pesticides that have not yet even been developed. In this study, we investigated a possible type of cross-resistance in the model fruit fly Drosophila melanogaster, some stocks of which are resistant to the very potent mushroom toxin α-amanitin. Because α-amanitin is solely produced by mushrooms, and because D. melanogaster does not feed on mushrooms in nature, the fruit flies should not be resistant to this toxin. In order to understand …

Stress Responses And Energy Storage In Drosophila Melanogaster Selected For Resistance To A Gram-Positive Bacillus Cereus Spores, Zhen Hu

School of Biological Sciences: Dissertations, Theses, and Student Research

A survival response study was carried out by using D. melanogaster and the opportunistic pathogen B. cereus as the agent of selection. The spores of B. cereus, a gram-positive bacteria that can cause the human pathogen disease, were applied in our artificial laboratory selection. Selected lines were treated with B. cereus spores. Wound control lines were punctured with a needle dipped into sterile H₂O. Control lines did not apply any treatment. Three different environmental treatments were used within each line type (autoclaved spores of B.cereus, sterile H₂O and no treatment). The autoclaved spores were …

Trip/Nopo E3 Ubiquitin Ligase Promotes Ubiquitylation Of Dna Polymerase Η, Heather A. Wallace, Julie A. Merkle, Michael C. Yu, Taloa G. Berg, Ethan Lee, Giovanni Bosco, Laura A. Lee

Dartmouth Scholarship

We previously identified a Drosophila maternal effect-lethal mutant named ‘no poles’ (nopo). Embryos from nopo females undergo mitotic arrest with barrel-shaped, acentrosomal spindles during the rapid cycles of syncytial embryogenesis because of activation of a Chk2-mediated DNA checkpoint. NOPO is the Drosophila homolog of human TNF receptor associated factor (TRAF)-interacting protein (TRIP), which has been implicated in TNF signaling. NOPO and TRIP contain RING domains closely resembling those of known E3 ubiquitin ligases. We herein sought to elucidate the mechanism by which TRIP/NOPO promotes genomic stability by performing a yeast two-hybrid screen to identify potential substrates/interactors. We identified members of …

Causes And Consequences Of Female Mate Choice In Drosophila Melanogaster: A Hemiclonal Analysis, Hannah Me Tennant

Theses and Dissertations (Comprehensive)

One of Darwin’s greatest questions, the reason why females prefer elaborate sexually selected male traits and displays, was elucidated by the Fisherian coevolution of male traits and female preferences. While variation in male attractiveness and ornamentation has received much attention, there has been little attempt to evaluate the causes and consequences of intraspecific variation in components of female preference. Furthermore, demonstrating a genetic basis to female preference does not answer the question of how within-population genetic variation is maintained.

Understanding the sources of variation in potential mating interactions between males and females is important because this variation determines the strength …

The Role Of Body Size On The Outcome Of Mating Interactions In Drosophila Melanogaster, Adam C. Lounsbury

Theses and Dissertations (Comprehensive)

Sexual selection is the process by which some individuals produce more and/or better quality offspring than others because they are better at securing mates. While this may be accomplished by defeating same-sex rivals (intrasexual selection), individuals of one sex (typically females) may also “decide” on the suitability of individuals of the opposite sex (typically males), resulting in intersexual selection on attractive traits. While a great deal of scrutiny has focused on how sexual selection influences male display traits, much less scrutiny has been directed toward the factors underlying female preference, including genetic variation, as well as the extent to which …

A Genetic, Transgenic, And Transcriptomic Analysis Of Larval Salivary Gland Physiology In Drosophila Melanogaster, Elana A. Paladino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cholesterol is the precursor to a unique class of lipophilic signaling molecules called steroid hormones that initiate the development of sexual characteristics, reactions to stress, and maintenance of metabolism, among many other functions. Although much progress has been made in understanding the function of these signaling hormones, we do not fully understand how a single steroid can cause many distinct, tissue-specific responses. Drosophila melanogaster is an effective model for understanding steroid hormone action because of its simplicity. The steroid molting hormone 20-hydroxyecdysone (hereafter, 20E) is the primary active steroid in Drosophila and mediates not only larval molts and the emergence …

Condensin Ii Promotes The Formation Of Chromosome Territories By Inducing Axial Compaction Of Polyploid Interphase Chromosomes, Christopher R. R. Bauer, Tom A. Hartl, Giovanni Bosco

Dartmouth Scholarship

The eukaryotic nucleus is both spatially and functionally partitioned. This organization contributes to the maintenance, expression, and transmission of genetic information. Though our ability to probe the physical structure of the genome within the nucleus has improved substantially in recent years, relatively little is known about the factors that regulate its organization or the mechanisms through which specific organizational states are achieved. Here, we show that Drosophila melanogaster Condensin II induces axial compaction of interphase chromosomes, globally disrupts interchromosomal interactions, and promotes the dispersal of peri-centric heterochromatin. These Condensin II activities compartmentalize the nucleus into discrete chromosome territories and indicate …

Abd-A Regulation By The Iab-8 Noncoding Rna, Maheshwar Gummalla, Robert K. Maeda, Javier J. Castro Alvarez, Henrik Gyurkovics, Kevin A. Edwards, Swetha Singari, Welcome Bender

Faculty Publications – Biological Sciences

The homeotic genes in Drosophila melanogaster are aligned on the chromosome in the order of the body segments that they affect. The genes affecting the more posterior segments repress the more anterior genes. This posterior dominance rule must be qualified in the case of abdominal-A (abd-A) repression by Abdominal-B (Abd-B). Animals lacking Abd-B show ectopic expression of abd-A in the epidermis of the eighth abdominal segment, but not in the central nervous system. Repression in these neuronal cells is accomplished by a 92 kb noncoding RNA. This "iab-8 RNA" produces a micro RNA to repress abd-A, but also has a …

Transcriptome Analysis Of Glue Secretion In Drosophila, William Mccurdy, Pawel Parafianowicz, Andrew Andres

McNair Poster Presentations

Steroid hormones control important developmental and physiological responses in animals, including humans. It is known that when a cell is exposed to a steroid hormone, there is an immediate change in the genes that are expressed into proteins. Of notable importance is steroid regulation in the salivary glands of larval Drosophila melanogaster and the corresponding physiological responses that are governed by treatment with the conserved insect steroid, 20-hydroxyecdysone (20E). Exposure to the steroid hormone 20E causes a change in gene expression that facilitates the secretion of glue glycoproteins from inside the cells into the lumen of the tissue. Altered gene …