Biology Commons^™

Apical Testis Structure And The Effects Of Cadmium Treatment On Spermatogenesis In Drosophila, Paulina J. Cardaci

Seton Hall University Dissertations and Theses (ETDs)

The fruit fly Drosophila melanogaster is used extensively as a model for studying molecular, genetic and cellular aspects of human disease and physiology. Our lab has used D. melanogaster and related species to study the structure of the testis stem cell niche, as well as other aspects of spermatogenesis. We previously revealed a novel stem cell niche structure in D. pseudoobscura, a distant relative of D. melanogaster. The signaling center of the D. melanogaster stem cell niche has a well-characterized rosette arrangement of fasciclin-positive cells terms the “hub”. D. pseudoobscura, however, lacks a punctuate hub and instead displays a …

Controlled Microfluidics To Examine Growth-Factor Induced Migration Of Neural Progenitors In The Drosophila Visual System, Cade Beck, Tanya Singh, Angela Farooqi, Tadmiri Venkatesh, Maribel Vazquez

Publications and Research

BACKGROUND:

The developing visual system in Drosophila melanogaster provides an excellent model with which to examine the effects of changing microenvironments on neural cell migration via microfluidics, because the combined experimental system enables direct genetic manipulation, in vivo observation, and in vitro imaging of cells, post-embryo. Exogenous signaling from ligands such as fibroblast growth factor (FGF) is well-known to control glia differentiation, cell migration, and axonal wrapping central to vision.

NEW METHOD:

The current study employs a microfluidic device to examine how controlled concentration gradient fields of FGF are able to regulate the migration of vision-critical glia cells with and …

Optogenetic Stimulation Of Drosophila Heart Rate At Different Temperatures And Ca2+ Concentrations, Yuechen Zhu, Henry Uradu, Zana R. Majeed, Robin L. Cooper

Biology Faculty Publications

Optogenetics is a revolutionary technique that enables noninvasive activation of electrically excitable cells. In mammals, heart rate has traditionally been modulated with pharmacological agents or direct stimulation of cardiac tissue with electrodes. However, implanted wires have been known to cause physical damage and damage from electrical currents. Here, we describe a proof of concept to optically drive cardiac function in a model organism, Drosophila melanogaster. We expressed the light sensitive channelrhodopsin protein ChR2.XXL in larval Drosophila hearts and examined light‐induced activation of cardiac tissue. After demonstrating optical stimulation of larval heart rate, the approach was tested at low temperature …

The Role Of Arp2/3 In Ring Canal Development In Drosophila Melanogaster, Marina Tipold

Undergraduate Honors Thesis Collection

Infertility and impaired fecundity affect 8.2 million women in the United States. Intercellular bridges are essential to the proper formation of germ cells in many organisms; therefore, learning more about how they are formed and regulated during the formation of sperm and eggs could provide insight into how defects in their structure can impact fertility. Intercellular bridges are actin-rich structures that connect developing germ cells to each other and allow the transfer of materials. I used the development of the fruit fly egg as a model system to study formation and regulation of intercellular bridges. Specifically, I investigated the role …

Genomic Insights Into The Ixodes Scapularis Tick Vector Of Lyme Disease, Monika Gulia-Nuss, Andrew B. Nuss, Jason M. Meyer, Daniel E. Sonenshine, R. Michael Roe, Robert M. Waterhouse, David B. Sattelle, Jose De La Fuente, Jose M. Ribeiro, Karine Megy

Biological Sciences Faculty Publications

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ~57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick-host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host 'questing', prolonged feeding, cuticle …

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 …

Flight Muscle Progenitor Populations In Drosophila Melanogaster, Elizabeth Carvosso Clarke

Biology ETDs

We use the Drosophila system to define how genes control muscle development and function. Many of the genes in the fruit fly, Drosophila melanogaster, are conserved with higher animals, and so our results can be important in understanding mechanisms of vertebrate muscle development and disease. Study of the flight muscle progenitor populations in Drosophila gives clearer understanding of the genetic regulatory networks that lead to the development of flight muscle. The direct flight muscles (DFMs) and indirect flight muscles (IFMs) arise from the myoblast population of the notal region of the Drosophila wing imaginal disc. Within the myoblast population, there …

Akirin-Mediated Gene Regulation During Cardiac Development, Austin M. Howard

Master of Science in Integrative Biology Theses

The highly conserved nuclear protein Akirin was previously identified as a cofactor that modulates Twist transcription factor activity during muscle development in Drosophila melanogaster. Akirin mediates an interaction between the Twist transcription factor and the multisubunit Brahma SWI/SNF-class chromatin remodeling complex at control elements of the Dmef2 locus to maintain optimal myogenic gene expression levels. Therefore, Akirin represents a class of novel secondary cofactors that work with transcription machinery to link transcription factor output with chromatin remodeling machinery to facilitate gene expression. Previous work establishes that Twist and Akirin also interact at Twist-responsive control elements of the tinman gene, …

The Gene Blistered Selectively Controls Muscle Type Differentiation In Drosophila Melanogaster, Ashley A. Deaguero

Biology ETDs

The muscle fiber is a structural unit of skeletal muscle in many organisms. Muscle fiber composition has been implicated in maintaining muscle longevity and controlling systemic energy homeostasis, however not much is known about how different types of muscle fibers are specified. The fruit fly Drosophila melanogaster provides a useful model to study specification and differentiation of different types of muscle fiber. In this study, the functional properties of the transcription factor blistered (bs) were explored. The gene bs is evolutionarily conserved and has a mammalian homologue, Serum Response Factor (SRF). When bs is genetically down-regulated in all muscles, only …

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 …

Analyzing The Interactions Of Kdm5/Lid And Sin3 In Drosophila Melanogaster, Ambikai Gajan

Wayne State University Dissertations

SIN3, the scaffold protein of a histone modifying complex is conserved from yeast to mammals. Drosophila SIN3 associates with both a histone deactylase RPD3 and a histone demethylase dKDM5/LID. Immunopurification of dKDM5/LID verifies a previously observed interaction with SIN3 and RPD3. Furthermore, deficiency of dKDM5/LID phenocopies deficiency of SIN3 in many cellular and developmental processes. Knockdown of both Sin3A and lid hinder cell proliferation in Drosophila cultured cells and developing flies. Knockdown of these genes also results in a curved wing phenotype implicating a role in wing development. Analysis of underlying gene expression changes upon decreased expression of SIN3, dKDM5/LID …

Autoregulation Of The Glial Gene Reversed Polarity In Drosophila Melanogaster, Jamie L. Wood

Electronic Theses and Dissertations

During development, cells of the nervous system begin as unspecified precursors and proceed along one of two developmental paths to become either neurons or glia. I seek to understand more about the genes that control this process, focusing on the lesser understood of the cell types, glial cells. Using Drosophila melanogaster as a model system, previous work from my lab and others has established the role of the master regulatory transcription factor Gcm in directing neuronal precursor cells to assume a lateral glial fate. Gcm acts on many target genes, one of which is reversed polarity (repo). repo is necessary …

Characterization Of Histidine Decarboxylase In Drosophila Using An Internal Flag Epitope, Maxwell Mianecki

Masters Theses

Histamine is a neurotransmitter in arthropods and is responsible for synaptic transmission in vision, mechanosensation, temperature sensing and sleep cycle in Drosophila. Histamine is synthesized by the enzyme histidine decarboxylase (HDC). While histamine is detectable within tissues using current immunofluorescent labeling techniques, immunological approaches have not been successful for HDC itself, with both direct antibodies and terminal epitope tags determined to be ineffective. In order to avoid loss of the epitope tag through putative N-­‐ and C-­‐terminal proteolytic cleavage, known to occur for HDC in other organisms, an internal epitope tag that does not disrupt enzyme function was utilized. A …

Aret: A Novel Regulator Of Alternative Splicing In The Flight Muscle Transcripts In Drosophila Melanogaster, Sandy Thi Oas

Biology ETDs

Drosophila melanogaster has been used as a model organism for understanding muscle development. Drosophila flight and jump muscles are distinct functionally and biochemically. This distinction is due to differentially expressed genes and differentially spliced mRNA transcripts. The exact mechanism of alternative splicing in somatic muscles is not well characterized. Aret was previously shown to be a transcriptional repressor, and has been implicated in splicing regulation based upon literature analysis and preliminary work. This study aims to define the regulatory role of Aret and the impact of alternative splicing on determining muscle diversification and fiber choice. We indicate the importance of …

Astrocyte-Specific Regulation Of Hmecp2 Expression In Drosophila, David Hess-Homeier, Chia-Yu Fan, Tarun Gupta, Ann-Shyn Chiang, Sarah J. Certel

Biological Sciences Faculty Publications

Alterations in the expression of Methyl-CpG-binding protein 2 (MeCP2) either by mutations or gene duplication leads to a wide spectrum of neurodevelopmental disorders including Rett Syndrome and MeCP2 duplication disorder. Common features of Rett Syndrome (RTT), MeCP2 duplication disorder, and neuropsychiatric disorders indicate that even moderate changes in MeCP2 protein levels result in functional and structural cell abnormalities. In this study, we investigated two areas of MeCP2 pathophysiology using Drosophila as a model system: the effects of MeCP2 glial gain-of-function activity on circuits controlling sleep behavior, and the cell-type specific regulation of MeCP2 expression. In this study, we first examined …

Lights And Larvae: Using Optogenetics To Teach Recombinant Dna And Neurobiology, John Titlow, Heidi Anderson, Robin L. Cooper

Biology Faculty Publications

Switching genes between organisms and controlling an animal’s brain using lasers may seem like science fiction, but with advancements in a technique called optogenetics, such experiments are now common in neuroscience research. Optogenetics combines recombinant DNA technology with a controlled light source to help researchers address biomedical questions in the life sciences. The technique has gained the most traction in neurobiology—the biology of the nervous system—where specific wavelengths of light are used to control or measure the activity of neurons in transgenic organisms (i.e., those with artificially inserted genes).

These optical recording and stimulation techniques are used in nervous system …

Differential Expression Of Snmps And Their Underlying Transcriptional Regulation In Chemosensory Pathways Of Drosophila, Richard A. Fandino

Theses and Dissertations

Insects possess complex and diverse chemosensory pathways which have specific phenotypes determined by the regulated expression of specific combinations of genes. While many of these genes (e.g. ORs and GRs) have very narrow expression patterns, associating with only a limited number of chemosensory sensilla, SNMPs show a very broad expression pattern. In Drosophila, SNMP1 and SNMP2 associate with the majority of olfactory and gustatory sensilla, but express in different cell types. In olfactory sensilla, SNMP1 and SNMP2 associate with trichoid or coeloconic neurons respectively, and both additionally express in a variety of sensilla support cells; in gustatory sensilla, SNMP2 expresses …

Comparative Modeling And Functional Characterization Of Two Enzymes Of The Cyclooxygenase Pathway In Drosophila Melanogaster, Yan Qi

Dissertations, Theses, and Capstone Projects

Eicosanoids are biologically active molecules oxygenated from twenty carbon polyunsaturated fatty acids. Natural eicosanoids exert potent biological effects in humans, and a great deal of pharmaceutical research has led to the discovery of compounds for selective inhibition of specific enzymes in eicosanoid biosynthesis. Coupled with different receptors, eicosanoids mediate various physiological and pathophysiological processes, including fever generation, pain response, vasoconstriction, vasodilation, platelet aggregation, platelet declumping, body temperature maintenance and sleep-wake cycle regulation. In mammals, the eicosanoid biosynthesis has three pathways: the cyclooxygenase (COX) pathway, the lipoxygenase (LOX) pathway and the epoxygenase pathway. The COX pathway synthesizes prostanoids, which are important …

Rala And Rab8 Regulate Drosophila Embryogenesis, Zhongyuan Zuo

Electronic Theses and Dissertations

Pseudocleavage furrow dynamics initiate at cycle 10 to help with mitotic divisions that lack cytokinesis. Permanent furrows then form at the beginning of cellularization (cycle 14). Cytoskeletal networks such as F-actin and non-muscle Myosin II have been demonstrated to be required for furrow formation and provide anchor points for chromosomal segregation. However, what drives the onset of furrow formation and membrane addition remains largely unclear. In my thesis, I have explored RalA and Rab8 function during furrow formation at metaphase and cellularization stages. These furrows are critical for correct chromosomal segregation, while disruption of furrow formation results in severe developmental …

The Postsynaptic Regulation Of Synaptic Strength In Drosophila, Daniel Michael Gertner

Legacy Theses & Dissertations (2009 - 2024)

Postsynaptic Ca2+ plays an important role in synaptic homeostasis and synaptic plasticity. Postsynaptic Ca2+ signals have been shown to regulate synaptic transmission at the Drosophila larval neuromuscular junction (NMJ), however, these signals have not been well characterized. This will explore how these signals regulate synaptic strength and what channels are involved. In previous lab experiments Ca2+ transients were observed during evoked and spontaneous release (Desai and Lnenicka, 2011). It was further demonstrated that a reduction in synaptic strength occurs following synaptic stimulation. It was hypothesized that the increase in postsynaptic Ca2+ following synaptic stimulation activates the gCS and causes a …

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 …

Genome-Wide Gene Expression Effects Of Sex Chromosome Imprinting In Drosophila, Bernardo Lemos, Alan T. Branco, Pan-Pan Jiang, Daniel L. Hartl, Colin D. Meiklejohn

School of Biological Sciences: Faculty Publications

Imprinting is well-documented in both plant and animal species. In Drosophila, the Y chromosome is differently modified when transmitted through the male and female germlines. Here, we report genome-wide gene expression effects resulting from reversed parent-of-origin of the X and Y chromosomes. We found that hundreds of genes are differentially expressed between adult male Drosophila melanogaster that differ in the maternal and paternal origin of the sex chromosomes. Many of the differentially regulated genes are expressed specifically in testis and midgut cells, suggesting that sex chromosome imprinting might globally impact gene expression in these tissues. In contrast, we observed much …

Drosophila Hematopoiesis: Markers And Methods For Molecular Genetic Analysis, Cory J. Evans, Ting Liu, Utpal Banerjee

Biology Faculty Works

Analyses of the Drosophila hematopoietic system are becoming more and more prevalent as developmental and functional parallels with vertebrate blood cells become more evident. Investigative work on the fly blood system has, out of necessity, led to the identification of new molecular markers for blood cell types and lineages and to the refinement of useful molecular genetic tools and analytical methods. This review briefly describes the Drosophila hematopoietic system at different developmental stages, summarizes the major useful cell markers and tools for each stage, and provides basic protocols for practical analysis of circulating blood cells and of the lymph gland, …

Dreadds In Drosophila: A Pharmacogenetic Approach For Controlling Behavior, Neuronal Signaling, And Physiology In The Fly, Jaime Becnel, Oralee Johnson, Zana R Majeed, Vi Tran, Bangning Yu, Bryan L. Roth, Robin L. Cooper, Edmund K. Kerut, Charles D. Nichols

Biology Faculty Publications

We have translated a powerful genetic tool, designer receptors exclusively activated by designer drugs (DREADDs), from mammalian systems to Drosophila melanogaster to selectively, rapidly, reversibly, and dose-dependently control behaviors and physiological processes in the fly. DREADDs are muscarinic acetylcholine G protein-coupled receptors evolved for loss of affinity to acetylcholine and for the ability to be fully activated by an otherwise biologically inert chemical, clozapine-N-oxide. We demonstrate its ability to control a variety of behaviors and processes in larvae and adults, including heart rate, sensory processing, diurnal behavior, learning and memory, and courtship. The advantages of this particular technology include the …

Inhibition Of Diuretic Stimulation Of An Insect Secretory Epithelium By A Cgmp-Dependent Protein Kinase, Kristen A. Ruka, Anna P. Miller, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

The rate of urine secretion by insect Malpighian tubules (MTs) is regulated by multiple diuretic and antidiuretic hormones, often working either synergistically or antagonistically. In the Drosophila melanogaster MT, only diuretic factors have been reported. Two such agents are the biogenic amine tyramine (TA) and the peptide drosokinin (DK), both of which act on the stellate cells of the tubule to increase transepithelial chloride conductance. In the current study, TA and DK signaling was quantified by microelectrode recording of the transepithelial potential in isolated Drosophila MTs. Treatment of tubules with cGMP caused a significant reduction in the depolarizing responses to …

Ontogenetic Variation In Cold Tolerance Plasticity In Drosophila: Is The Bogert Effect Bogus?, Katherine A Mitchell, Brent J Sinclair, John S Terblanche

Biology Publications

Ontogenetic variation in plasticity is important to understanding mechanisms and patterns of thermal tolerance variation. The Bogert effect postulates that, to compensate for their inability to behaviourally thermoregulate, less-mobile life stages of ectotherms are expected to show greater plasticity of thermal tolerance than more-mobile life stages. We test this general prediction by comparing plasticity of thermal tolerance (rapid cold-hardening, RCH) between mobile adults and less-mobile larvae of 16 Drosophila species. We find an RCH response in adults of 13 species but only in larvae of four species. Thus, the Bogert effect is not as widespread as expected.

Little Evidence For Demasculinization Of The Drosophila X Chromosome Among Genes Expressed In The Male Germline, Colin D. Meiklejohn, Daven C. Presgraves

School of Biological Sciences: Faculty Publications

Male-biased genes—those expressed at higher levels in males than in females—are underrepresented on the X chromosome of Drosophila melanogaster. Several evolutionary models have been posited to explain this so-called demasculinization of the X. Here, we show that the apparent paucity of male-biased genes on the X chromosome is attributable to global X-autosome differences in expression in Drosophila testes, owing to a lack of sex chromosome dosage compensation in the male germline, but not to any difference in the density of testis-specific or testis-biased genes on the X chromosome. First,using genome-wide gene expression data from 20 tissues,we find no evidence …

Variation Of Nimc1 Expression In Drosophila Stocks And Transgenic Strains, Viktor Honti, Gyöngyi Cinege, Gábor Csordás, Éva Kurucz, János Zsámboki, Cory J. Evans, Utpal Banerjee, István Andó

Biology Faculty Works

The NimC1 molecule has been described as a phagocytosis receptor, and is being used as a marker for professional phagocytes, the plasmatocytes, in Drosophila melanogaster. In studies including tumor-biology, developmental biology, and cell mediated immunity, monoclonal antibodies (P1a and P1b) to the NimC1 antigen are used. As we observed that these antibodies did not react with plasmatocytes of several strains and genetic combinations, a molecular analysis was performed on the structure of the nimC1 gene. In these strains we found 2 deletions and an insertion within the nimC1 gene, which may result in the production of a truncated NimC1 protein. …