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Habenstein J, Schmitt F, Liessem S, Ly A, Trede D, Wegener C, Predel R, Rössler W, Neupert S. Transcriptomic, peptidomic, and mass spectrometry imaging analysis of the brain in the ant Cataglyphis nodus. J Neurochem 2021; 158:391-412. [PMID: 33704768 DOI: 10.1111/jnc.15346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 12/16/2022]
Abstract
Behavioral flexibility is an important cornerstone for the ecological success of animals. Social Cataglyphis nodus ants with their age-related polyethism characterized by age-related behavioral phenotypes represent a prime example for behavioral flexibility. We propose neuropeptides as powerful candidates for the flexible modulation of age-related behavioral transitions in individual ants. As the neuropeptidome of C. nodus was unknown, we collected a comprehensive peptidomic data set obtained by transcriptome analysis of the ants' central nervous system combined with brain extract analysis by Q-Exactive Orbitrap mass spectrometry (MS) and direct tissue profiling of different regions of the brain by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS. In total, we identified 71 peptides with likely bioactive function, encoded on 49 neuropeptide-, neuropeptide-like, and protein hormone prepropeptide genes, including a novel neuropeptide-like gene (fliktin). We next characterized the spatial distribution of a subset of peptides encoded on 16 precursor proteins with high resolution by MALDI MS imaging (MALDI MSI) on 14 µm brain sections. The accuracy of our MSI data were confirmed by matching the immunostaining patterns for tachykinins with MSI ion images from consecutive brain sections. Our data provide a solid framework for future research into spatially resolved qualitative and quantitative peptidomic changes associated with stage-specific behavioral transitions and the functional role of neuropeptides in Cataglyphis ants.
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Affiliation(s)
- Jens Habenstein
- Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg, Würzburg, Germany
| | - Franziska Schmitt
- Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg, Würzburg, Germany
| | - Sander Liessem
- Department of Biology, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Alice Ly
- Bruker Daltonik GmbH, Bremen, Germany
| | - Dennis Trede
- SCiLS, Zweigniederlassung Bremen der Bruker Daltonik GmbH, Bremen, Germany
| | - Christian Wegener
- Theodor-Boveri-Institute, Neurobiology and Genetics, Würzburg Insect Research, University of Würzburg, Würzburg, Germany
| | - Reinhard Predel
- Department of Biology, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Wolfgang Rössler
- Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg, Würzburg, Germany
| | - Susanne Neupert
- Department of Biology, Institute for Zoology, University of Cologne, Cologne, Germany.,Department of Biology, University of Kassel, Kassel, Germany
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2
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Nässel DR, Zandawala M. Recent advances in neuropeptide signaling in Drosophila, from genes to physiology and behavior. Prog Neurobiol 2019; 179:101607. [PMID: 30905728 DOI: 10.1016/j.pneurobio.2019.02.003] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/18/2019] [Accepted: 02/28/2019] [Indexed: 12/11/2022]
Abstract
This review focuses on neuropeptides and peptide hormones, the largest and most diverse class of neuroactive substances, known in Drosophila and other animals to play roles in almost all aspects of daily life, as w;1;ell as in developmental processes. We provide an update on novel neuropeptides and receptors identified in the last decade, and highlight progress in analysis of neuropeptide signaling in Drosophila. Especially exciting is the huge amount of work published on novel functions of neuropeptides and peptide hormones in Drosophila, largely due to the rapid developments of powerful genetic methods, imaging techniques and innovative assays. We critically discuss the roles of peptides in olfaction, taste, foraging, feeding, clock function/sleep, aggression, mating/reproduction, learning and other behaviors, as well as in regulation of development, growth, metabolic and water homeostasis, stress responses, fecundity, and lifespan. We furthermore provide novel information on neuropeptide distribution and organization of peptidergic systems, as well as the phylogenetic relations between Drosophila neuropeptides and those of other phyla, including mammals. As will be shown, neuropeptide signaling is phylogenetically ancient, and not only are the structures of the peptides, precursors and receptors conserved over evolution, but also many functions of neuropeptide signaling in physiology and behavior.
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Affiliation(s)
- Dick R Nässel
- Department of Zoology, Stockholm University, Stockholm, Sweden.
| | - Meet Zandawala
- Department of Zoology, Stockholm University, Stockholm, Sweden; Department of Neuroscience, Brown University, Providence, RI, USA.
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3
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Uddin Z, Boonsupthip W. Development and characterization of a new nonenzymatic colored time–temperature indicator. J FOOD PROCESS ENG 2019. [DOI: 10.1111/jfpe.13027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zahoor Uddin
- Department of Food Science and Technology, Faculty of agro‐IndustryKasetsart University Bangkok Thailand
| | - Waraporn Boonsupthip
- Department of Food Science and Technology, Faculty of agro‐IndustryKasetsart University Bangkok Thailand
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4
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Cropper EC, Jing J, Vilim FS, Barry MA, Weiss KR. Multifaceted Expression of Peptidergic Modulation in the Feeding System of Aplysia. ACS Chem Neurosci 2018; 9:1917-1927. [PMID: 29309115 DOI: 10.1021/acschemneuro.7b00447] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neuropeptides are present in species throughout the animal kingdom and generally exert actions that are distinct from those of small molecule transmitters. It has, therefore, been of interest to define the unique behavioral role of this class of substances. Progress in this regard has been made in experimentally advantageous invertebrate preparations. We focus on one such system, the feeding circuit in the mollusc Aplysia. We review research conducted over several decades that played an important role in establishing that peptide cotransmitters are released under behaviorally relevant conditions. We describe how this was accomplished. For example, we describe techniques developed to purify novel peptides, localize them to identified neurons, and detect endogenous peptide release. We also describe physiological experiments that demonstrated that peptides are bioactive under behaviorally relevant conditions. The feeding system is like others in that peptides exert effects that are both convergent and divergent. Work in the feeding system clearly illustrates how this creates potential for behavioral flexibility. Finally, we discuss experiments that determined physiological consequences of one of the hallmark features of peptidergic modulation, its persistence. Research in the feeding system demonstrated that this persistence can change network state and play an important role in determining network output.
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Affiliation(s)
- Elizabeth C. Cropper
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, New York 10029, United States
| | - Jian Jing
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, New York 10029, United States
- State Key Laboratory of Pharmaceutical Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Ferdinand S. Vilim
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, New York 10029, United States
| | - Michael A. Barry
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, New York 10029, United States
| | - Klaudiusz R. Weiss
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, New York 10029, United States
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5
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WEclMon - A simple and robust camera-based system to monitor Drosophila eclosion under optogenetic manipulation and natural conditions. PLoS One 2017; 12:e0180238. [PMID: 28658318 PMCID: PMC5489222 DOI: 10.1371/journal.pone.0180238] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/12/2017] [Indexed: 11/19/2022] Open
Abstract
Eclosion in flies and other insects is a circadian-gated behaviour under control of a central and a peripheral clock. It is not influenced by the motivational state of an animal, and thus presents an ideal paradigm to study the relation and signalling pathways between central and peripheral clocks, and downstream peptidergic regulatory systems. Little is known, however, about eclosion rhythmicity under natural conditions, and research into this direction is hampered by the physically closed design of current eclosion monitoring systems. We describe a novel open eclosion monitoring system (WEclMon) that allows the puparia to come into direct contact with light, temperature and humidity. We demonstrate that the system can be used both in the laboratory and outdoors, and shows a performance similar to commercial closed funnel-type monitors. Data analysis is semi-automated based on a macro toolset for the open imaging software Fiji. Due to its open design, the WEclMon is also well suited for optogenetic experiments. A small screen to identify putative neuroendocrine signals mediating time from the central clock to initiate eclosion showed that optogenetic activation of ETH-, EH and myosuppressin neurons can induce precocious eclosion. Genetic ablation of myosuppressin-expressing neurons did, however, not affect eclosion rhythmicity.
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6
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Cattenoz PB, Giangrande A. Revisiting the role of the Gcm transcription factor, from master regulator to Swiss army knife. Fly (Austin) 2016; 10:210-8. [PMID: 27434165 DOI: 10.1080/19336934.2016.1212793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Master genes are known to induce the differentiation of a multipotent cell into a specific cell type. These molecules are often transcription factors that switch on the regulatory cascade that triggers cell specification. Gcm was first described as the master gene of the glial fate in Drosophila as it induces the differentiation of neuroblasts into glia in the developing nervous system. Later on, Gcm was also shown to regulate the differentiation of blood, tendon and peritracheal cells as well as that of neuronal subsets. Thus, the glial master gene is used in at least 4 additional systems to promote differentiation. To understand the numerous roles of Gcm, we recently reported a genome-wide screen of Gcm direct targets in the Drosophila embryo. This screen provided new insight into the role and mode of action of this powerful transcription factor, notably on the interactions between Gcm and major differentiation pathways such as the Hedgehog, Notch and JAK/STAT. Here, we discuss the mode of action of Gcm in the different systems, we present new tissues that require Gcm and we revise the concept of 'master gene'.
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Affiliation(s)
- Pierre B Cattenoz
- a Department of Functional Genomics and Cancer , Institut de Génétique et de Biologie Moléculaire et Cellulaire , Illkirch , France
| | - Angela Giangrande
- a Department of Functional Genomics and Cancer , Institut de Génétique et de Biologie Moléculaire et Cellulaire , Illkirch , France
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7
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Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila. Genetics 2015; 202:191-219. [PMID: 26567182 PMCID: PMC4701085 DOI: 10.1534/genetics.115.182154] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/03/2015] [Indexed: 12/21/2022] Open
Abstract
High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain-containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades.
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8
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Sánchez-Herrero E. Hox targets and cellular functions. SCIENTIFICA 2013; 2013:738257. [PMID: 24490109 PMCID: PMC3892749 DOI: 10.1155/2013/738257] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/20/2013] [Indexed: 06/03/2023]
Abstract
Hox genes are a group of genes that specify structures along the anteroposterior axis in bilaterians. Although in many cases they do so by modifying a homologous structure with a different (or no) Hox input, there are also examples of Hox genes constructing new organs with no homology in other regions of the body. Hox genes determine structures though the regulation of targets implementing cellular functions and by coordinating cell behavior. The genetic organization to construct or modify a certain organ involves both a genetic cascade through intermediate transcription factors and a direct regulation of targets carrying out cellular functions. In this review I discuss new data from genome-wide techniques, as well as previous genetic and developmental information, to describe some examples of Hox regulation of different cell functions. I also discuss the organization of genetic cascades leading to the development of new organs, mainly using Drosophila melanogaster as the model to analyze Hox function.
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Affiliation(s)
- Ernesto Sánchez-Herrero
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Nicolás Cabrera 1, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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9
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Kim WJ, Jan LY, Jan YN. A PDF/NPF neuropeptide signaling circuitry of male Drosophila melanogaster controls rival-induced prolonged mating. Neuron 2013; 80:1190-205. [PMID: 24314729 PMCID: PMC3867312 DOI: 10.1016/j.neuron.2013.09.034] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2013] [Indexed: 12/21/2022]
Abstract
A primary function of males for many species involves mating with females for reproduction. Drosophila melanogaster males respond to the presence of other males by prolonging mating duration to increase the chance of passing on their genes. To understand the basis of such complex behaviors, we examine the genetic network and neural circuits that regulate rival-induced Longer-Mating-Duration (LMD). Here, we identify a small subset of clock neurons in the male brain that regulate LMD via neuropeptide signaling. LMD requires the function of pigment-dispersing factor (PDF) in four s-LNv neurons and its receptor PDFR in two LNd neurons per hemisphere, as well as the function of neuropeptide F (NPF) in two neurons within the sexually dimorphic LNd region and its receptor NPFR1 in four s-LNv neurons per hemisphere. Moreover, rival exposure modifies the neuronal activities of a subset of clock neurons involved in neuropeptide signaling for LMD.
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Affiliation(s)
- Woo Jae Kim
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry, and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
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10
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Laneve P, Delaporte C, Trebuchet G, Komonyi O, Flici H, Popkova A, D'Agostino G, Taglini F, Kerekes I, Giangrande A. The Gcm/Glide molecular and cellular pathway: new actors and new lineages. Dev Biol 2012; 375:65-78. [PMID: 23276603 DOI: 10.1016/j.ydbio.2012.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/18/2012] [Accepted: 12/14/2012] [Indexed: 12/21/2022]
Abstract
In Drosophila, the transcription factor Gcm/Glide plays a key role in cell fate determination and cellular differentiation. In light of its crucial biological impact, major efforts have been put for analyzing its properties as master regulator, from both structural and functional points of view. However, the lack of efficient antibodies specific to the Gcm/Glide protein precluded thorough analyses of its regulation and activity in vivo. In order to relieve such restraints, we designed an epitope-tagging approach to "FLAG"-recognize and analyze the functional protein both in vitro (exogenous Gcm/Glide) and in vivo (endogenous protein). We here (i) reveal a tight interconnection between the small RNA and the Gcm/Glide pathways. AGO1 and miR-1 are Gcm/Glide targets whereas miR-279 negatively controls Gcm/Glide expression (ii) identify a novel cell population, peritracheal cells, expressing and requiring Gcm/Glide. Peritracheal cells are non-neuronal neurosecretory cells that are essential in ecdysis. In addition to emphasizing the importance of following the distribution and the activity of endogenous proteins in vivo, this study provides new insights and a novel frame to understand the Gcm/Glide biology.
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Affiliation(s)
- Pietro Laneve
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
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11
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Choi C, Cao G, Tanenhaus AK, McCarthy EV, Jung M, Schleyer W, Shang Y, Rosbash M, Yin JCP, Nitabach MN. Autoreceptor control of peptide/neurotransmitter corelease from PDF neurons determines allocation of circadian activity in drosophila. Cell Rep 2012; 2:332-44. [PMID: 22938867 DOI: 10.1016/j.celrep.2012.06.021] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 05/04/2012] [Accepted: 06/28/2012] [Indexed: 01/03/2023] Open
Abstract
Drosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral-ventral pacemaker neurons (LN(v)s) that secrete the neuropeptide PDF (pigment dispersing factor). Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR)-expressing dorsal clock neurons in organizing circadian activity. Although LN(v)s also express functional PDFR, the role of these autoreceptors has remained enigmatic. Here, we show that (1) PDFR activation in LN(v)s shifts the balance of circadian activity from evening to morning, similar to behavioral responses to summer-like environmental conditions, and (2) this shift is mediated by stimulation of the Gα,s-cAMP pathway and a consequent change in PDF/neurotransmitter corelease from the LN(v)s. These results suggest another mechanism for environmental control of the allocation of circadian activity and provide new general insight into the role of neuropeptide autoreceptors in behavioral control circuits.
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Affiliation(s)
- Charles Choi
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA
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12
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Zandawala M, Lytvyn Y, Taiakina D, Orchard I. Cloning of the cDNA, localization, and physiological effects of FGLamide-related allatostatins in the blood-gorging bug, Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:10-21. [PMID: 22061445 DOI: 10.1016/j.ibmb.2011.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 09/27/2011] [Accepted: 10/07/2011] [Indexed: 05/31/2023]
Abstract
Allatostatins (ASTs) are insect neuropeptides that were first identified as inhibitors of juvenile hormone biosynthesis by the corpora allata. There are three families of ASTs in insects, defined by their C-terminus conserved regions, one of which is FGLamide. Here we determine, for the first time in a hemipteran, the complete 1013 bp cDNA sequence encoding the Rhodnius prolixus FGLa/ASTs (Rhopr-FGLa/ASTs), and confirm the transcript size using northern blot. Phylogenetic analysis suggests that the Rhopr-FGLa/AST prepropeptide is most similar to the FGLa/AST precursors identified in Hymenoptera. Reverse-transcriptase PCR demonstrates that the Rhopr-FGLa/AST transcript is highly expressed in the central nervous system (CNS) in unfed fifth-instar R. prolixus, and is reduced in expression in CNS dissected from one day old blood-fed insects. Fluorescent in situ hybridization shows transcript expression in neurons in each ganglion of the CNS, but also in cells located on peripheral nerves. Rhopr-FGLa/ASTs dose-dependently inhibit contractions of the anterior midgut and hindgut, suggesting a role in feeding-related physiological events.
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Affiliation(s)
- Meet Zandawala
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada L5L 1C6.
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13
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Segment-specific generation of Drosophila Capability neuropeptide neurons by multi-faceted Hox cues. Dev Biol 2011; 353:72-80. [PMID: 21354130 PMCID: PMC3094758 DOI: 10.1016/j.ydbio.2011.02.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 02/15/2011] [Accepted: 02/16/2011] [Indexed: 12/26/2022]
Abstract
In the Drosophila ventral nerve cord, the three pairs of Capability neuropeptide-expressing Va neurons are exclusively found in the second, third and fourth abdominal segments (A2–A4). To address the underlying mechanisms behind such segment-specific cell specification, we followed the developmental specification of these neurons. We find that Va neurons are initially generated in all ventral nerve cord segments and progress along a common differentiation path. However, their terminal differentiation only manifests itself in A2–A4, due to two distinct mechanisms: segment-specific programmed cell death (PCD) in posterior segments, and differentiation to an alternative identity in segments anterior to A2. Genetic analyses reveal that the Hox homeotic genes are involved in the segment-specific appearance of Va neurons. In posterior segments, the Hox gene Abdominal-B exerts a pro-apoptotic role on Va neurons, which involves the function of several RHG genes. Strikingly, this role of Abd-B is completely opposite to its role in the segment-specific apoptosis of other classes of neuropeptide neurons, the dMP2 and MP1 neurons, where Abd-B acts in an anti-apoptotic manner. In segments A2–A4 we find that abdominal A is important for the terminal differentiation of Va cell fate. In the A1 segment, Ultrabithorax acts to specify an alternate Va neuron fate. In contrast, in thoracic segments, Antennapedia suppresses the Va cell fate. Thus, Hox genes act in a multi-faceted manner to control the segment-specific appearance of the Va neuropeptide neurons in the ventral nerve cord.
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14
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Ierusalimsky VN, Balaban PM. Family of CNP neuropeptides: common morphology in various invertebrates. Cell Tissue Res 2011; 343:483-97. [PMID: 21271258 DOI: 10.1007/s00441-010-1119-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Accepted: 12/10/2010] [Indexed: 10/18/2022]
Abstract
Neuropeptides expressed in the command neurons for withdrawal behavior were originally detected in the the central nervous system (CNS) of the terrestrial snail Helix (command neurons peptides, CNP). The family of CNP-like neuropeptides bears a C-terminal signature sequence Tyr-Pro-Arg-X. Using antisera against two of them, we have studied the CNS of various invertebrates belonging to the phyla of mollusks, annelids and insects. The immunoreactive neurons were detected in all studied species. Stained neurons were either interneurons projecting along the CNS ganglia chain, or sensory neurons, or neurohormonal cells. Beyond common morphological features, the immunoreactive cells had another similarity: the level of CNP expression depended on the functional state of the animal. Thus, the homologous neuropeptides in evolutionary distant invertebrate species possess some common morphological and functional features.
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Affiliation(s)
- Victor N Ierusalimsky
- Institute of Higher Nervous Activity and Neurophysiology RAS, 5A Butlerova Str, Moscow 117485, Russia.
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15
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Asuncion-Uchi M, Shawa HE, Martin T, Fuse M. Different actions of ecdysis-triggering hormone on the brain and ventral nerve cord of the hornworm, Manduca sexta. Gen Comp Endocrinol 2010; 166:54-65. [PMID: 19699740 PMCID: PMC2823964 DOI: 10.1016/j.ygcen.2009.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 07/23/2009] [Accepted: 08/13/2009] [Indexed: 10/20/2022]
Abstract
Ecdysis, or the shedding of the old cuticle, depends on coordinated stereotyped behaviors, regulated by a number of neuropeptides. In the hornworm, Manduca sexta, two neuropeptides interact, namely ecdysis-triggering hormone (ETH) and eclosion hormone. We looked at the effects of ETH in vivo and in vitro, on the brain and the ventral nerve cord to determine the roles played by these hormones. We monitored ecdysis onset and the presence of cGMP and eclosion hormone immunoreactivity. In vivo, only a fraction of larvae lacking the cell bodies containing eclosion hormone, and injected with ETH, were able to undergo ecdysis, with a delayed response. These animals showed strongest cGMP immunoreactivity in the subesophageal and thoracic ganglia, with concomitant reductions in eclosion hormone immunoreactivity in descending axons in comparison with animals not undergoing ecdysis. Animals lacking the brain showed reduced to no cGMP levels in all ganglia. In vitro, isolated CNS preparations lacking the brain initiated ecdysis motor programs after incubation in ETH, with faster onset times than controls, and with reduced cGMP immunoreactivity. If ETH was applied only to the brain of the isolated CNS, cGMP immunoreactivity was noted primarily in the subesophageal and thoracic ganglia, with a decrease in eclosion hormone immunoreactivity in descending axons. ETH addition to the rest of the nerve cord showed reduced eclosion hormone immunoreactivity but little to no cGMP immunoreactivity in any ganglion. Controls showed strong cGMP immunoreactivity in all ganglia, and even greater reductions in eclosion hormone staining after ETH application. These results support previous suggestions that eclosion hormone is required for a positive feedback loop with ETH as well as onset of an inhibitory component, but also suggest that ETH stimulates eclosion hormone release at multiple spike initiation zones. The resultant up regulation of cGMP does not appear to be required for onset of ecdysis. A new model for ecdysis regulation is considered.
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Affiliation(s)
| | - Hani El Shawa
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Tunyalee Martin
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Megumi Fuse
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
- Corresponding author: ; fax (415-338-1130); phone (415-405-0728)
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16
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Morton DB, Stewart JA, Langlais KK, Clemens-Grisham RA, Vermehren A. Synaptic transmission in neurons that express the Drosophila atypical soluble guanylyl cyclases, Gyc-89Da and Gyc-89Db, is necessary for the successful completion of larval and adult ecdysis. ACTA ACUST UNITED AC 2008; 211:1645-56. [PMID: 18456892 DOI: 10.1242/jeb.014472] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Insect ecdysis is a precisely coordinated series of behavioral and hormonal events that occur at the end of each molt. A great deal is known about the hormonal events that underlie this process, although less is known about the neuronal circuitry involved. In this study we identified two populations of neurons that are required for larval and adult ecdyses in the fruit fly, Drosophila melanogaster (Meigen). These neurons were identified by using the upstream region of two genes that code for atypical soluble guanylyl cyclases to drive tetanus toxin in the neurons that express these cyclases to block their synaptic activity. Expression of tetanus toxin in neurons that express Gyc-89Da blocked adult eclosion whereas expression of tetanus toxin in neurons that express Gyc-89Db prevented the initiation of the first larval ecdysis. Expression of tetanus toxin in the Gyc-89Da neurons also resulted in about 50% lethality just prior to pupariation; however, this was probably due to suffocation in the food as lethality was prevented by stopping the larvae from burrowing deep within the food. This result is consistent with our model that the atypical soluble guanylyl cyclases can act as molecular oxygen detectors. The expression pattern of these cyclases did not overlap with any of the neurons containing peptides known to regulate ecdysis and eclosion behaviors. By using the conditional expression of tetanus toxin we were also able to demonstrate that synaptic activity in the Gyc-89Da and Gyc-89Db neurons is required during early adult development for adult eclosion.
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Affiliation(s)
- David B Morton
- Department of Integrative Biosciences, Oregon Health and Science University, 611 SW Campus Drive, Portland, OR 97239, USA.
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17
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Park D, Veenstra JA, Park JH, Taghert PH. Mapping peptidergic cells in Drosophila: where DIMM fits in. PLoS One 2008; 3:e1896. [PMID: 18365028 PMCID: PMC2266995 DOI: 10.1371/journal.pone.0001896] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Accepted: 02/22/2008] [Indexed: 11/24/2022] Open
Abstract
The bHLH transcription factor DIMMED has been associated with the differentiation of peptidergic cells in Drosophila. However, whether all Drosophila peptidergic cells express DIMM, and the extent to which all DIMM cells are peptidergic, have not been determined. To address these issues, we have mapped DIMM expression in the central nervous system (CNS) and periphery in the late larval stage Drosophila. At 100 hr after egg-laying, DIMM immunosignals are largely congruent with a dimm-promoter reporter (c929-GAL4) and they present a stereotyped pattern of 306 CNS cells and 52 peripheral cells. We assigned positional values for all DIMM CNS cells with respect to reference gene expression patterns, or to patterns of secondary neuroblast lineages. We could assign provisional peptide identities to 68% of DIMM-expressing CNS cells (207/306) and to 73% of DIMM-expressing peripheral cells (38/52) using a panel of 24 markers for Drosophila neuropeptide genes. Furthermore, we found that DIMM co-expression was a prevalent feature within single neuropeptide marker expression patterns. Of the 24 CNS neuropeptide gene patterns we studied, six patterns are >90% DIMM-positive, while 16 of 22 patterns are >40% DIMM-positive. Thus most or all DIMM cells in Drosophila appear to be peptidergic, and many but not all peptidergic cells express DIMM. The co-incidence of DIMM-expression among peptidergic cells is best explained by a hypothesis that DIMM promotes a specific neurosecretory phenotype we term LEAP. LEAP denotes Large cells that display Episodic release of Amidated Peptides.
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Affiliation(s)
- Dongkook Park
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | | | - Jae H. Park
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee–Knoxville, Knoxville, Tennessee, United States of America
| | - Paul H. Taghert
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
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18
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A Drosophila gain-of-function screen for candidate genes involved in steroid-dependent neuroendocrine cell remodeling. Genetics 2008; 178:883-901. [PMID: 18245346 DOI: 10.1534/genetics.107.082487] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The normal functioning of neuroendocrine systems requires that many neuropeptidergic cells change, to alter transmitter identity and concentration, electrical properties, and cellular morphology in response to hormonal cues. During insect metamorphosis, a pulse of circulating steroids, ecdysteroids, governs the dramatic remodeling of larval neurons to serve adult-specific functions. To identify molecular mechanisms underlying metamorphic remodeling, we conducted a neuropeptidergic cell-targeted, gain-of-function genetic screen. We screened 6097 lines. Each line permitted Gal4-regulated transcription of flanking genes. A total of 58 lines, representing 51 loci, showed defects in neuropeptide-mediated developmental transitions (ecdysis or wing expansion) when crossed to the panneuropeptidergic Gal4 driver, 386Y-Gal4. In a secondary screen, we found 29 loci that produced wing expansion defects when crossed to a crustacean cardioactive peptide (CCAP)/bursicon neuron-specific Gal4 driver. At least 14 loci disrupted the formation or maintenance of adult-specific CCAP/bursicon cell projections during metamorphosis. These include components of the insulin and epidermal growth factor signaling pathways, an ecdysteroid-response gene, cabut, and an ubiquitin-specific protease gene, fat facets, with known functions in neuronal development. Several additional genes, including three micro-RNA loci and two factors related to signaling by Myb-like proto-oncogenes, have not previously been implicated in steroid signaling or neuronal remodeling.
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19
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Santos JG, Vömel M, Struck R, Homberg U, Nässel DR, Wegener C. Neuroarchitecture of peptidergic systems in the larval ventral ganglion of Drosophila melanogaster. PLoS One 2007; 2:e695. [PMID: 17668072 PMCID: PMC1933254 DOI: 10.1371/journal.pone.0000695] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Accepted: 06/15/2007] [Indexed: 11/24/2022] Open
Abstract
Recent studies on Drosophila melanogaster and other insects have revealed important insights into the functions and evolution of neuropeptide signaling. In contrast, in- and output connections of insect peptidergic circuits are largely unexplored. Existing morphological descriptions typically do not determine the exact spatial location of peptidergic axonal pathways and arborizations within the neuropil, and do not identify peptidergic in- and output compartments. Such information is however fundamental to screen for possible peptidergic network connections, a prerequisite to understand how the CNS controls the activity of peptidergic neurons at the synaptic level. We provide a precise 3D morphological description of peptidergic neurons in the thoracic and abdominal neuromeres of the Drosophila larva based on fasciclin-2 (Fas2) immunopositive tracts as landmarks. Comparing the Fas2 "coordinates" of projections of sensory or other neurons with those of peptidergic neurons, it is possible to identify candidate in- and output connections of specific peptidergic systems. These connections can subsequently be more rigorously tested. By immunolabeling and GAL4-directed expression of marker proteins, we analyzed the projections and compartmentalization of neurons expressing 12 different peptide genes, encoding approximately 75% of the neuropeptides chemically identified within the Drosophila CNS. Results are assembled into standardized plates which provide a guide to identify candidate afferent or target neurons with overlapping projections. In general, we found that putative dendritic compartments of peptidergic neurons are concentrated around the median Fas2 tracts and the terminal plexus. Putative peptide release sites in the ventral nerve cord were also more laterally situated. Our results suggest that i) peptidergic neurons in the Drosophila ventral nerve cord have separated in- and output compartments in specific areas, and ii) volume transmission is a prevailing way of peptidergic communication within the CNS. The data can further be useful to identify colocalized transmitters and receptors, and develop peptidergic neurons as new landmarks.
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Affiliation(s)
- Jonathan G. Santos
- Emmy Noether Neuropeptide Group, Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
- Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
| | - Matthias Vömel
- Emmy Noether Neuropeptide Group, Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
- Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
| | - Rafael Struck
- Emmy Noether Neuropeptide Group, Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
- Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
| | - Uwe Homberg
- Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
| | - Dick R. Nässel
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Christian Wegener
- Emmy Noether Neuropeptide Group, Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
- Animal Physiology, Department of Biology, Philipps-University, Marburg, Germany
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20
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Zitnan D, Kim YJ, Zitnanová I, Roller L, Adams ME. Complex steroid-peptide-receptor cascade controls insect ecdysis. Gen Comp Endocrinol 2007; 153:88-96. [PMID: 17507015 PMCID: PMC4955941 DOI: 10.1016/j.ygcen.2007.04.002] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Revised: 03/22/2007] [Accepted: 04/01/2007] [Indexed: 11/29/2022]
Abstract
Insect ecdysis sequence is composed of pre-ecdysis, ecdysis and post-ecdysis behaviors controlled by a complex cascade of peptide hormones from endocrine Inka cells and neuropeptides in the central nervous system (CNS). Inka cells produce pre-ecdysis and ecdysis triggering hormones (ETH) which activate the ecdysis sequence through receptor-mediated actions on specific neurons in the CNS. Multiple experimental approaches have been used to determine mechanisms of ETH expression and release from Inka cells and its action on the CNS of moths and flies. During the preparatory phase 1-2 days prior to ecdysis, high ecdysteroid levels induce expression of ETH receptors in the CNS and increased ETH production in Inka cells, which coincides with expression of nuclear ecdysone receptor (EcR) and transcription factor cryptocephal (CRC). However, high ecdysteroid levels prevent ETH release from Inka cells. Acquisition of Inka cell competence to release ETH requires decline of ecdysteroid levels and beta-FTZ-F1 expression few hours prior to ecdysis. The behavioral phase is initiated by ETH secretion into the hemolymph, which is controlled by two brain neuropeptides-corazonin and eclosion hormone (EH). Corazonin acts on its receptor in Inka cells to elicit low level ETH secretion and initiation of pre-ecdysis, while EH induces cGMP-mediated ETH depletion and consequent activation of ecdysis. The activation of both behaviors is accomplished by ETH action on central neurons expressing ETH receptors A and B (ETHR-A and B). These neurons produce numerous excitatory or inhibitory neuropeptides which initiate or terminate different phases of the ecdysis sequence. Our data indicate that insect ecdysis is a very complex process characterized by two principal steps: (1) ecdysteroid-induced expression of receptors and transcription factors in the CNS and Inka cells. (2) Release and interaction of Inka cell peptide hormones and multiple central neuropeptides to control consecutive phases of the ecdysis sequence.
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Affiliation(s)
- D Zitnan
- Institute of Zoology, Slovak Academy of Sciences, Dubravska cesta 9, 84506 Bratislava, Slovakia.
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21
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Neupert S, Johard HAD, Nässel DR, Predel R. Single-Cell Peptidomics ofDrosophila melanogasterNeurons Identified by Gal4-Driven Fluorescence. Anal Chem 2007; 79:3690-4. [PMID: 17439240 DOI: 10.1021/ac062411p] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neuropeptides are widespread signal molecules that display a great chemical and functional diversity. Predictions of neuropeptide cleavage from precursor proteins are not always correct, and thus, biochemical identification is essential. Single-cell analysis is valuable to identify peptides processed from a single precursor, but also to determine coexpression of further neuropeptides from other precursors. We have developed an approach to isolate single identified neurons from the fruit fly Drosophila melanogaster for mass spectrometric analysis. By using Gal4 promoter lines to drive green fluorescent protein under UAS control, we identified specific peptidergic neurons. These neurons were isolated singly under a fluorescence microscope and subjected to MALDI-TOF mass spectrometry. Two Gal4 lines were used here to identify pigment-dispersing factor (PDF) and hugin-expressing neurons. We found that the large PDF expressing clock neurons only give rise to a single peptide, PDF. The three different classes of hugin expressing neurons all display the same mass signal, identical to pyrokinin-2. The other peptide predicted from the hugin precursor, hugin gamma, was not detected in any of the cells. Single-cell peptidomics is a powerful tool in Drosophila neuroscience since Gal4 drivers can be produced for all known neuropeptide genes and thus provide detailed information about neuropeptide complements in neurons of interest.
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Affiliation(s)
- Susanne Neupert
- Institute of Zoology, Friedrich-Schiller-University Jena, Erbertstrasse 1, 07743 Jena, Germany
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22
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Ierusalimsky VN, Balaban PM. Neuropeptides of Drosophila related to molluscan neuropeptides: dependence of the immunoreactivity pattern on the ontogenetic stage and functional state. Brain Res 2007; 1152:32-41. [PMID: 17434150 DOI: 10.1016/j.brainres.2007.03.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 03/12/2007] [Accepted: 03/13/2007] [Indexed: 10/23/2022]
Abstract
The CNP neuropeptides (Command Neuron Peptides) were first found in the command neurons for withdrawal behavior in the terrestrial snail. Given the fact that certain peptides can be found in various invertebrates, we examined Drosophila brains to determine if CNP-like peptides were present. Two types of antisera were used: one against CNP2, which was expected to recognize peptide products of the genes "hugin", "capa", CG6371, and a second antiserum against CNP4, which was expected to recognize neuropeptides encoded by the gene "capa" only. In larvae, both antibodies stained the abdominal perisympathetic organ, and several groups of neurons in the suboesophageal ganglia, while two neuronal clusters in the protocerebrum were stained with CNP2 antibody exclusively. The set of peptidergic neurons was conserved throughout all larval development. In the suboesophageal ganglia, the number of immunoreactive neurons apparently decreased at the pupae stage, and only one pair of large neurons in the caudal part of the suboesophageal ganglia was detected in adults. Experimental body injury led in the adult fruit flies to appearance of additional immunoreactive neurons, the pattern of staining becoming similar to that in larval CNS. The study demonstrates that the number of neurons expressing CNP-like immunoreactivity depends on the developmental stage and functional state of the animal, and that the CNP2-like and CNP4-like neuropeptides are colocalized in some neurons. We conclude that the family of CNP-like neuropeptides seems to be common for various invertebrate phyla.
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Affiliation(s)
- Victor N Ierusalimsky
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology Russian Academy of Sciences, Moscow , Russia.
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23
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Nachman RJ, Coast GM. Structure-activity relationships for in vitro diuretic activity of CAP2b in the housefly. Peptides 2007; 28:57-61. [PMID: 17161506 DOI: 10.1016/j.peptides.2006.09.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Revised: 09/15/2006] [Accepted: 09/15/2006] [Indexed: 11/17/2022]
Abstract
A series of truncated and Ala-replacement analogs of the peptide Manse-CAP2b (pELYAFPRV-NH(2)) were assayed for diuretic activity on Malpighian tubules of the housefly Musca domestica (M. domestica). The C-terminal hexapeptide proved to be the active core, the minimum sequence required to retain significant diuretic activity. However, full activity required the C-terminal heptapeptide, which was equipotent with the most active of the native housefly CAP2b peptides. Replacement of Arg(7) and Val(8) with Ala led to inactivity and a large 70-fold drop in potency, respectively, indicating that these were critical residues. The Leu(2) was semicritical, where a six-fold loss in potency was observed. Conversely, the replacement of all other residues with Ala led to much smaller effects on potency and these positions were considered to be noncritical. This structure-activity relationship data can aid in the design of mimetic agonist/antagonist analogs of this diuretic peptide family with enhanced biostability and bioavailability, as tools for arthropod endocrinologists and as potential pest management agents capable of disrupting the water balance in pest flies.
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Affiliation(s)
- Ronald J Nachman
- Areawide Pest Management Research, Southern Plains Agricultural Research Center, USDA, College Station, TX 77845, USA.
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24
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Lin DM, Loveall B, Ewer J, Deitcher DL, Sucher NJ. Characterization of mRNA expression in single neurons. Methods Mol Biol 2007; 399:133-152. [PMID: 18309930 DOI: 10.1007/978-1-59745-504-6_10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
How neurons differ from each other is largely determined by their specific repertoire of mRNAs. The genes expressed by a given neuron reflect its developmental history, its interaction with other cells, and its synaptic activity. Since the introduction of reverse transcription polymerase chain reaction (RT-PCR), it has been possible to identify specific mRNAs present in small samples of total RNA. But isolating RNA from only those cells of interest, and not others, represents a significant challenge. Several approaches can be used to isolate RNA from selected neurons. Following whole-cell patch-clamp recording, mRNA can be harvested from living cells by aspirating the cytoplasm into the patch-clamp pipette. Transcripts expressed in the recorded neuron can then be amplified by RT-PCR. Another way of isolating identified neurons is to use cell-specific promoters to drive the expression of a marker gene such as green fluorescent protein (GFP). RNA can then be isolated from GFP-positive cells. In a tissue context, laser microdissection can also be used to excise the cells of interest directly into an RNA isolation solution. The above methods of RNA isolation can also be combined with RNA amplification and microarray technology to identify specific transcripts that are unique to the cell type being studied. Here we provide detailed protocols for harvesting RNA from single cells, methods for RNA purification, and PCR amplification.
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Affiliation(s)
- David M Lin
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
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25
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Predel R, Russell WK, Neupert S, Russell DH, Esquivel JF, Nachman RJ. Identification of the first neuropeptides from the CNS of Hemiptera: CAPA peptides of the southern green stinkbug Nezara viridula (L.). Peptides 2006; 27:2670-7. [PMID: 16824649 DOI: 10.1016/j.peptides.2006.05.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 05/10/2006] [Accepted: 05/11/2006] [Indexed: 10/24/2022]
Abstract
A direct mass spectrometric investigation of nerve homologs of the abdominal perisympathetic organs was employed to reveal the first and complete sequences of CAPA peptides from a hemipteran species, the southern green stinkbug Nezara viridula. Side-chain fragmentations allowed the assignment of internal Leu/Ile; on-plate acetylation was used to distinguish between the mass-related Lys and Gln. The following sequences were obtained: DQLFPFPRV-NH(2) (CAPA-PVK-1), EQLIPFPRV-NH(2) (CAPA-PVK-2), and NGSAGNGGLWFGPRL/I-NH(2) (CAPA-PK). CAPA-PVKs are associated with the regulation of diuresis in insects, and identification of those native to a hemipteran will provide the experimental basis to better understand regulation of water balance in this family of insects.
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Affiliation(s)
- Reinhard Predel
- Areawide Pest Management Research, Southern Plains Agricultural Research Center, USDA, 2881 F/B Road, College Station, TX 77845, USA.
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26
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Gauthier SA, Hewes RS. Transcriptional regulation of neuropeptide and peptide hormone expression by the Drosophila dimmed and cryptocephal genes. ACTA ACUST UNITED AC 2006; 209:1803-15. [PMID: 16651547 DOI: 10.1242/jeb.02202] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The regulation of neuropeptide and peptide hormone gene expression is essential for the development and function of neuroendocrine cells in integrated physiological networks. In insects, a decline in circulating ecdysteroids triggers the activation of a neuroendocrine system to stimulate ecdysis, the behaviors used to shed the old cuticle at the culmination of each molt. Here we show that two evolutionarily conserved transcription factor genes, the basic helix-loop-helix (bHLH) gene dimmed (dimm) and the basic-leucine zipper (bZIP) gene cryptocephal (crc), control expression of diverse neuropeptides and peptide hormones in Drosophila. Central nervous system expression of three neuropeptide genes, Dromyosuppressin, FMRFamide-related and Leucokinin, is activated by dimm. Expression of Ecdysis triggering hormone (ETH) in the endocrine Inka cells requires crc; homozygous crc mutant larvae display markedly reduced ETH levels and corresponding defects in ecdysis. crc activates ETH expression though a 382 bp enhancer, which completely recapitulates the ETH expression pattern. The enhancer contains two evolutionarily conserved regions, and both are imperfect matches to recognition elements for activating transcription factor-4 (ATF-4), the vertebrate ortholog of the CRC protein and an important intermediate in cellular responses to endoplasmic reticulum stress. These regions also contain a putative ecdysteroid response element and a predicted binding site for the products of the E74 ecdysone response gene. These results suggest that convergence between ATF-related signaling and an important intracellular steroid response pathway may contribute to the neuroendocrine regulation of insect molting.
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Affiliation(s)
- Sebastien A Gauthier
- Department of Zoology, Stephenson Research and Technology Center, University of Oklahoma, Norman, OK 73019, USA.
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27
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Santos JG, Pollák E, Rexer KH, Molnár L, Wegener C. Morphology and metamorphosis of the peptidergic Va neurons and the median nerve system of the fruit fly, Drosophila melanogaster. Cell Tissue Res 2006; 326:187-99. [PMID: 16685531 DOI: 10.1007/s00441-006-0211-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Accepted: 03/29/2006] [Indexed: 11/28/2022]
Abstract
Metamorphosis is a fundamental developmental process and has been intensively studied for various neuron types of Drosophila melanogaster. However, detailed accounts of the fate of identified peptidergic neurons are rare. We have performed a detailed study of the larval morphology and pupal remodelling of identified peptidergic neurons, the CAPA-expressing Va neurons of D. melanogaster. In the larva, Va neurons innervate abdominal median and transverse nerves that are typically associated with perisympathetic organs (PSOs), major neurohaemal release sites in insects. Since median and transverse nerves are lacking in the adult, Va neurites have to undergo substantial remodelling during metamorphosis. We have examined the hitherto uncharacterised gross morphology of the thoracic PSOs and the abdominal median and transverse nerves by scanning electron microscopy and found that the complete reduction of these structures during metamorphosis starts around pupal stage P7 and is completed at P9. Concomitantly, neurite pruning of the Va neurons begins at P6 and is preceded by the high expression of the ecdysone receptor (EcR) subtype B1 in late L3 larvae and the first pupal stages. New neuritic outgrowth mainly occurs from P7-P9 and coincides with the expression of EcR-A, indicating that the remodelling of the Va neurons is under ecdysteroid control. Immunogold-labelling has located the CAPA peptides to large translucent vesicles, which are released from the transverse nerves, as suggested by fusion profiles. Hence, the transverse nerves may serve a neurohaemal function in D. melanogaster.
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Affiliation(s)
- Jonathan G Santos
- Emmy Noether Neuropeptide Group, Department of Biology, Animal Physiology, Philipps University, Karl-von-Frisch-Strasse, 35032, Marburg, Germany
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28
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Wegener C, Reinl T, Jänsch L, Predel R. Direct mass spectrometric peptide profiling and fragmentation of larval peptide hormone release sites in Drosophila melanogaster reveals tagma-specific peptide expression and differential processing. J Neurochem 2006; 96:1362-74. [PMID: 16441518 DOI: 10.1111/j.1471-4159.2005.03634.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Regulatory peptides represent a diverse group of messenger molecules. In insects, they are produced by endocrine cells as well as secretory neurones within the CNS. Many regulatory peptides are released as hormones into the haemolymph to regulate, for example, diuresis, heartbeat or ecdysis behaviour. Hormonal release of neuropeptides takes place at specialized organs, so-called neurohaemal organs. We have performed a mass spectrometric characterization of the peptide complement of the main neurohaemal organs and endocrine cells of the Drosophila melanogaster larva to gain insight into the hormonal communication possibilities of the fruit fly. Using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and MALDI-TOF-TOF tandem mass spectrometry, we detected 23 different peptides of which five were unpredicted by previous genome screenings. We also found a hitherto unknown peptide product of the capa gene in the ring gland and transverse nerves, suggesting that it might be released as hormone. Our results show that the peptidome of the neurohaemal organs is tagma-specific and does not change during metamorphosis. We also provide evidence for the first case of differential prohormone processing in Drosophila.
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Affiliation(s)
- Christian Wegener
- Emmy Noether Neuropeptide Group, Animal Physiology, Philipps-University, Marburg, Germany
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29
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Hyun S, Lee Y, Hong ST, Bang S, Paik D, Kang J, Shin J, Lee J, Jeon K, Hwang S, Bae E, Kim J. Drosophila GPCR Han is a receptor for the circadian clock neuropeptide PDF. Neuron 2006; 48:267-78. [PMID: 16242407 DOI: 10.1016/j.neuron.2005.08.025] [Citation(s) in RCA: 219] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Revised: 06/16/2005] [Accepted: 08/19/2005] [Indexed: 11/22/2022]
Abstract
The pigment-dispersing factor (PDF) is a neuropeptide controlling circadian behavioral rhythms in Drosophila, but its receptor is not yet known. From a large-scale temperature preference behavior screen in Drosophila, we isolated a P insertion mutant that preferred different temperatures during the day and night. This mutation, which we named han, reduced the transcript level of CG13758. We found that Han was expressed specifically in 13 pairs of circadian clock neurons in the adult brain. han null flies showed arrhythmic circadian behavior in constant darkness. The behavioral characteristics of han null mutants were similar to those of pdf null mutants. We also found that PDF binds specifically to S2 cells expressing Han, which results in the elevation of cAMP synthesis. Therefore, we herein propose that Han is a PDF receptor regulating circadian behavioral rhythm through coordination of activities of clock neurons.
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Affiliation(s)
- Seogang Hyun
- Department of Biological Sciences, Korea Advanced Institute of Science & Technology, 373-1 Guseong-Dong, Yuseong-Gu, Daejeon 305-701, Korea
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30
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Truman JW. Hormonal Control of Insect Ecdysis: Endocrine Cascades for Coordinating Behavior with Physiology. VITAMINS & HORMONES 2005; 73:1-30. [PMID: 16399406 DOI: 10.1016/s0083-6729(05)73001-6] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- James W Truman
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
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Adolfsen B, Saraswati S, Yoshihara M, Littleton JT. Synaptotagmins are trafficked to distinct subcellular domains including the postsynaptic compartment. ACTA ACUST UNITED AC 2004; 166:249-60. [PMID: 15263020 PMCID: PMC2172321 DOI: 10.1083/jcb.200312054] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The synaptotagmin family has been implicated in calcium-dependent neurotransmitter release, although Synaptotagmin 1 is the only isoform demonstrated to control synaptic vesicle fusion. Here, we report the characterization of the six remaining synaptotagmin isoforms encoded in the Drosophila genome, including homologues of mammalian Synaptotagmins 4, 7, 12, and 14. Like Synaptotagmin 1, Synaptotagmin 4 is ubiquitously present at synapses, but localizes to the postsynaptic compartment. The remaining isoforms were not found at synapses (Synaptotagmin 7), expressed at very low levels (Synaptotagmins 12 and 14), or in subsets of putative neurosecretory cells (Synaptotagmins α and β). Consistent with their distinct localizations, overexpression of Synaptotagmin 4 or 7 cannot functionally substitute for the loss of Synaptotagmin 1 in synaptic transmission. Our results indicate that synaptotagmins are differentially distributed to unique subcellular compartments. In addition, the identification of a postsynaptic synaptotagmin suggests calcium-dependent membrane-trafficking functions on both sides of the synapse.
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Affiliation(s)
- Bill Adolfsen
- The Picower Center for Learning and Memory, Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA
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Han M, Park D, Vanderzalm PJ, Mains RE, Eipper BA, Taghert PH. Drosophila uses two distinct neuropeptide amidating enzymes, dPAL1 and dPAL2. J Neurochem 2004; 90:129-41. [PMID: 15198673 DOI: 10.1111/j.1471-4159.2004.02464.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Neuropeptide alpha-amidation is a common C-terminal modification of secretory peptides, frequently required for biological activity. In mammals, amidation is catalyzed by the sequential actions of two enzymes [peptidylglycine-alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL)] that are co-synthesized within a single bifunctional precursor. The Drosophila genome predicts expression of one monofunctional PHM gene and two monofunctional PAL genes. Drosophila PHM encodes an active enzyme that is required for peptide amidation in vivo. Here we initiate studies of the two Drosophila PAL genes. dPAL1 has two predicted transmembrane domains, whereas dPAL2 is predicted to be soluble and secreted. dPAL2 expressed in heterologous cells is secreted readily and co-localized with hormone. In contrast, dPAL1 is secreted poorly, even when expressed with a cleaved signal replacing the predicted transmembrane domains; the majority of dPAL1 stays in the endoplasmic reticulum. Both proteins display PAL enzymatic activity. Compared to the catalytic core of rat PAL, the two Drosophila lyases have higher K(m) values, higher pH optima and similarly broad divalent metal ion requirements. Antibodies to dPAL1 and dPAL2 reveal co-expression in many identified neuroendocrine neurons. Although dPAL1 is broadly expressed, dPAL2 is found in only a limited subset of neurons. dPAL1 expression is highly correlated with the non-amidated peptide proctolin. Tissue immunostaining demonstrates that dPAL1 is largely localized to the cell soma, whereas dPAL2 is distributed throughout neuronal processes.
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Affiliation(s)
- Mei Han
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri, USA
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33
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Park D, Han M, Kim YC, Han KA, Taghert PH. Ap-let neurons--a peptidergic circuit potentially controlling ecdysial behavior in Drosophila. Dev Biol 2004; 269:95-108. [PMID: 15081360 DOI: 10.1016/j.ydbio.2004.01.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Revised: 01/14/2004] [Accepted: 01/14/2004] [Indexed: 10/26/2022]
Abstract
Here we describe a novel set of peptidergic neurons conserved throughout all developmental stages in the Drosophila central nervous system (CNS). We show that a small complement of 28 apterous-expressing cells (Ap-let neurons) in the ventral nerve cord (VNC) of Drosophila larvae co-express numerous gene products. The products include the neuroendocrine-specific bHLH regulator called Dimmed (Dimm), four neuropeptide biosynthetic enzymes (PC2, Fur1, PAL2, and PHM), and a specific dopamine receptor subtype (dDA1). For the PC2, Fur1, and PAL2 enzymes, and for the dDA1 receptor, this neuronal pattern represents the vast majority of their total expression in the VNC. In addition, while Dimm and PHM are present in the peritracheal Inka cells in larvae, pupae, and adults, Ap, PC2, Fur1, PAL2, and dDA1 are not. PC2, PAL2, and DA1 receptor expression were all controlled by both dimm and ap. Previous genetic analysis of animals deficient in PC2 revealed an abnormal larval ecdysis phenotype. Together, these data support the hypothesis that the small cohort of Ap-let interneurons regulates larval ecdysis behavior by secretion of an unidentified amidated peptide(s). This hypothesis further predicts that the production of the Ap-let neuropeptide(s) is dependent on each of four specific enzymes, and that a certain aspect(s) of its production and/or release is regulated by dopamine input.
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Affiliation(s)
- Dongkook Park
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
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34
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Husain QM, Ewer J. Use of targetable gfp-tagged neuropeptide for visualizing neuropeptide release following execution of a behavior. ACTA ACUST UNITED AC 2004; 59:181-91. [PMID: 15085536 DOI: 10.1002/neu.10309] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Previous work has shown that a transgene consisting of a fusion between the rat atrial natriuretic peptide and a green fluorescent protein reporter (ANF-gfp) is processed, localized, and released, as would be an endogenous neuropeptide when it is expressed in the nervous system of Drosophila melanogaster using the GAL4/UAS expression system. Here we have tested the utility of this targetable transgene for detecting neuropeptide release following the execution of a peptide-controlled behavior. For the behavior we used ecdysis, the behavior expressed by insects to shed their old cuticle at the end of the molt. We found that larval ecdysis was accompanied by a readily detectable reduction in gfp fluorescence from relevant secretory cells in the periphery and peptidergic neurons in the CNS. We also found that expression of the ANF-gfp products did not have detrimental effects on larval ecdysis or adult circadian rhythmicity, when the transgene was expressed in peptidergic cells that are known to control these behaviors. Finally, we used a broadly expressed GAL4 driver to show that the UAS-ANF-gfp transgene could be used to identify axons that show a reduction in gfp fluorescence following the expression of ecdysis behavior. These findings, coupled with the availability of an increasing number of strains bearing different GAL4 drivers, suggest that this transgene will be a useful tool for identifying peptidergic neurons and secretory cells (and, eventually, their secretory product) that release their peptide content during the occurrence, in the intact animal, of a developmental, physiological or behavioral process of interest.
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Affiliation(s)
- Qasim M Husain
- Cornell University, Entomology Department, 5130 Comstock Hall, Ithaca, New York 14850, USA
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35
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Britz FC, Hirth IC, Deitmer JW. Second messenger cascade of glial responses evoked by interneuron activity and by a myomodulin peptide in the leech central nervous system. Eur J Neurosci 2004; 19:983-92. [PMID: 15009146 DOI: 10.1111/j.0953-816x.2004.03192.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The giant glial cell in the neuropil of segmental ganglia of the leech Hirudo medicinalis responds to the activity of the Leydig interneuron and to a peptide of the myomodulin family, the presumed transmitter mediating the Leydig neuron-to-giant glial cell transmission, with a membrane hyperpolarization due to an increased membrane K+ conductance [Britz et al. (2002) Glia, 38, 215-227]. We have now studied the second messenger cascade initiated by Leydig neuron stimulation and by the endogenous myomodulin (MMHir) in the voltage-clamped giant glial cell. Glial responses to both stimuli are mediated by a G-protein-coupled receptor linked to adenylyl cyclase by the following criteria: (i) injection of GDP-beta-S, but not GDP, resulted in an irreversible decrease of the glial responses to both stimuli; (ii) the responses to both stimuli were reversibly inhibited by the adenylyl cyclase inhibitor SQ22,536; and (3) bath-applied di-butyryl-cyclic AMP, but not di-butyryl-cyclic GMP, elicited an outward current, which reduced the responses elicited by neuronal stimulation or myomodulin. A cocktail of protein kinase (PK) inhibitors (H-8, KT5720), the PKA antagonist Rp-cAMPS, or presumed inhibitors of cyclic nucleotide channels, LY83583 and l-cis-diltiazem, had no effect on the glial responses. Our results suggest that Leydig neuron stimulation and MMHir activate a cAMP-mediated K+ conductance in the glial cell, which appeared neither to be due to the activation of PKA nor of known cyclic nucleotide-gated channels directly.
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Affiliation(s)
- Frank C Britz
- Abteilung für Allgemeine Zoologie, FB Biologie, Universität Kaiserslautern, Postfach 3049, D-67653 Kaiserslautern, Germany
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36
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Predel R, Wegener C, Russell WK, Tichy SE, Russell DH, Nachman RJ. Peptidomics of CNS-associated neurohemal systems of adultDrosophila melanogaster: A mass spectrometric survey of peptides from individual flies. J Comp Neurol 2004; 474:379-92. [PMID: 15174081 DOI: 10.1002/cne.20145] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Neuropeptides are important messenger molecules that influence nearly all physiological processes. In insects, they can be released as neuromodulators within the central nervous system (CNS) or as neurohormones into the hemolymph. We analyzed the peptidome of neurohormonal release sites and associated secretory peptidergic neurons of adult Drosophila melanogaster. MALDI-TOF mass spectrometric analyzes were performed on single organs or cell cluster from individual flies. This first peptidomic characterization in adult fruit flies revealed 32 different neuropeptides. Peptides not directly predictable from previously cloned or annotated precursor genes were sequenced by tandem mass spectrometry. These peptides turned out to be either intermediate products of neuropeptide processing or shorter versions of known peptides. We found that the peptidome of the CNS-associated neurohemal organs is tagma-specific in Drosophila. Abdominal neurohemal organs and their supplying peptidergic neurons contain the capa gene products periviscerokinins and pyrokinin-1, thoracic neurohemal organs contain FMRFamides, and the neurohemal release sites of the brain contain pyrokinin-1(2-15), pyrokinin-2, corazonin, myosuppressin, and sNPF as their major putative release products. Our results show that peptidomic approaches are well suited to study differential neuropeptide expression or posttranslational modifications in morphologically defined parts of the nervous system and in a developmental and physiological context in animals as small as Drosophila melanogaster.
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Affiliation(s)
- Reinhard Predel
- Saxon Academy of Sciences, Research Group Jena, 07743 Jena, Germany.
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37
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Taylor CAM, Winther AME, Siviter RJ, Shirras AD, Isaac RE, Nässel DR. Identification of a proctolin preprohormone gene (Proct) ofDrosophila melanogaster: Expression and predicted prohormone processing. ACTA ACUST UNITED AC 2003; 58:379-91. [PMID: 14750150 DOI: 10.1002/neu.10301] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Proctolin was the first insect neuropeptide to be sequenced and has been the subject of many physiological and pharmacological studies in insects and crustaceans. We have identified a Drosophila gene (CG7105, Proct) encoding a precursor protein containing the neuropeptide proctolin (RYLPT). In situ hybridization with a riboprobe to the Proct gene revealed a distribution of transcript in neurons of the larval central nervous system (CNS) matching that seen with antiserum to proctolin. An antiserum raised to a sequence in the precursor downstream of proctolin labeled the same neurons as those seen with the antiproctolin antisera. The predicted protein encoded by Proct has a single copy of the RYLPT sequence that directly follows the predicted signal peptidase cleavage point and precedes a consensus recognition site for a furinlike processing endoprotease. Ectopic expression of Proct in the CNS and midgut via the GAL4-UAS system, using an Actin5C-GAL4 driver, confirmed that the predicted preproproctolin can be processed to generate immunoreactive proctolin peptide. Pupae over-expressing Proct displayed a 14% increase in heart rate, providing evidence in support of a cardioacceleratory endocrine function for proctolin in Drosophila. The distribution of proctolin suggests roles as a neuromodulator in motoneurons and interneurons, and as a neurohormone that could be released from brain neurosecretory cells with terminations in the ring gland.
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38
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Affiliation(s)
- Paul H Taghert
- Anatomy and Neurobiology, Washington University School of Medicine, St Louis, Missouri 63110, USA
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39
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Park Y, Kim YJ, Dupriez V, Adams ME. Two subtypes of ecdysis-triggering hormone receptor in Drosophila melanogaster. J Biol Chem 2003; 278:17710-5. [PMID: 12586820 DOI: 10.1074/jbc.m301119200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insect ecdysis is a hormonally programmed physiological sequence that enables insects to escape their old cuticle at the end of each developmental stage. The immediate events leading to ecdysis, which are initiated upon release of ecdysis-triggering hormones (ETH) into the bloodstream, include respiratory inflation and sequential stereotypic behaviors that facilitate shedding of the cuticle. Here we report that the Drosophila gene CG5911 encodes two functionally distinct subtypes of G protein-coupled receptors through alternative splicing (CG5911a and CG5911b) that respond preferentially to ecdysis-triggering hormones of flies and moths. These subtypes show differences in ligand sensitivity and specificity, suggesting that they may play separate roles in ETH signaling. At significantly higher concentrations (>100-fold), certain insect and vertebrate peptides also activate these receptors, providing evidence that CG5911 is evolutionarily related to the thyrotropin-releasing hormone and neuromedin U receptors. The ETH signaling system in insects is a vital system that provides opportunities for the construction of models for the molecular basis of stereotypic animal behavior as well as a target for the design of more sophisticated insect-selective pest control strategies.
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Affiliation(s)
- Yoonseong Park
- Department of Entomology, University of California, Riverside, California 92521, USA.
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40
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Suster ML, Martin JR, Sung C, Robinow S. Targeted expression of tetanus toxin reveals sets of neurons involved in larval locomotion in Drosophila. JOURNAL OF NEUROBIOLOGY 2003; 55:233-46. [PMID: 12672020 DOI: 10.1002/neu.10202] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The Drosophila larva is widely used for studies of neuronal development and function, yet little is known about the neuronal basis of locomotion in this model organism. Drosophila larvae crawl over a plain substrate by performing repetitive waves of forward peristalsis alternated by brief episodes of head swinging and turning. To identify sets of central and peripheral neurons required for the spatial or temporal pattern of larval locomotion, we blocked neurotransmitter release from defined populations of neurons by targeted expression of tetanus toxin light chain (TeTxLC) with the GAL4/UAS system. One hundred fifty GAL4 lines were crossed to a UAS-TeTxLC strain and a motion-analysis system was used to identify larvae with abnormal movement patterns. Five lines were selected that show discrete locomotor defects (i.e., increased turning and pausing) and these defects are correlated with diverse sets of central neurons. One line, 4C-GAL4, caused an unusual circling behavior that is correlated with approximately 200 neurons, including dopaminergic and peptidergic interneurons. Expression of TeTxLC in all dopaminergic and serotonergic but not in peptidergic neurons, caused turning deficits that are similar to those of 4C-GAL4/TeTxLC larvae. The results presented here provide a basis for future genetic studies of motor control in the Drosophila larva.
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41
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Hewes RS, Park D, Gauthier SA, Schaefer AM, Taghert PH. The bHLH protein Dimmed controls neuroendocrine cell differentiation in Drosophila. Development 2003; 130:1771-81. [PMID: 12642483 DOI: 10.1242/dev.00404] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neuroendocrine cells are specialized to produce, maintain and release large stores of secretory peptides. We show that the Drosophila dimmed/Mist1 bHLH gene confers such a pro-secretory phenotype on neuroendocrine cells. dimmed is expressed selectively in central and peripheral neuroendocrine cells. In dimmed mutants, these cells survive, and adopt normal cell fates and morphology. However, they display greatly diminished levels of secretory peptide mRNAs, and of diverse peptides and proteins destined for regulated secretion. Secretory peptide levels are lowered even in the presence of artificially high secretory peptide mRNA levels. In addition, overexpression of dimmed in a wild-type background produces a complimentary phenotype: an increase in secretory peptide levels by neuroendocrine cells, and an increase in the number of cells displaying a neuroendocrine phenotype. We propose that dimmed encodes an integral component of a novel mechanism by which diverse neuroendocrine lineages differentiate and maintain the pro-secretory state.
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Affiliation(s)
- Randall S Hewes
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
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42
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Allan DW, St Pierre SE, Miguel-Aliaga I, Thor S. Specification of neuropeptide cell identity by the integration of retrograde BMP signaling and a combinatorial transcription factor code. Cell 2003; 113:73-86. [PMID: 12679036 DOI: 10.1016/s0092-8674(03)00204-6] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Individual neurons express only one or a few of the many identified neurotransmitters and neuropeptides, but the molecular mechanisms controlling their selection are poorly understood. In the Drosophila ventral nerve cord, the six Tv neurons express the neuropeptide gene FMRFamide. Each Tv neuron resides within a neuronal cell group specified by the LIM-homeodomain gene apterous. We find that the zinc-finger gene squeeze acts in Tv cells to promote their unique axon pathfinding to a peripheral target. There, the BMP ligand Glass bottom boat activates the Wishful thinking receptor, initiating a retrograde BMP signal in the Tv neuron. This signal acts together with apterous and squeeze to activate FMRFamide expression. Reconstituting this "code," by combined BMP activation and apterous/squeeze misexpression, triggers ectopic FMRFamide expression in peptidergic neurons. Thus, an intrinsic transcription factor code integrates with an extrinsic retrograde signal to select a specific neuropeptide identity within peptidergic cells.
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Affiliation(s)
- Douglas W Allan
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
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43
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Zitnan D, Zitnanová I, Spalovská I, Takác P, Park Y, Adams ME. Conservation of ecdysis-triggering hormone signalling in insects. J Exp Biol 2003; 206:1275-89. [PMID: 12624163 DOI: 10.1242/jeb.00261] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pre-ecdysis- and ecdysis-triggering hormones (PETH and ETH) from endocrine Inka cells initiate ecdysis in moths and Drosophila through direct actions on the central nervous system (CNS). Using immunohistochemistry, we found Inka cells in representatives of all major insect orders. In most insects, Inka cells are numerous, small and scattered throughout the tracheal system. Only some higher holometabolous insects exhibit 8-9 pairs of large Inka cells attached to tracheae in each prothoracic and abdominal segment. The number and morphology of Inka cells can be very variable even in the same individuals or related insects, but all produce peptide hormones that are completely released at each ecdysis. Injection of tracheal extracts prepared from representatives of several insect orders induces pre-ecdysis and ecdysis behaviours in pharate larvae of Bombyx, indicating functional similarity of these peptides. We isolated several PETH-immunoreactive peptides from tracheal extracts of the cockroach Nauphoeta cinerea and the bug Pyrrhocoris apterus and identified the gene encoding two putative ETHs in the mosquito Anopheles gambiae. Inka cells also are stained with antisera to myomodulin, FMRFamide and other peptides sharing RXamide carboxyl termini. However, our enzyme immunoassays show that these antisera cross-react with PETH and ETH. Our results suggest that Inka cells of different insects produce only peptide hormones closely related to PETH and ETH, which are essential endocrine factors required for activation of the ecdysis behavioural sequence.
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Affiliation(s)
- D Zitnan
- Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 84206 Bratislava, Slovakia.
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44
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Abstract
A myomodulin peptide has been suggested to mediate the response of the giant glial cells to stimulation of the Leydig interneuron in the central nervous system of the leech Hirudo medicinalis [Eur. J. Neurosci. 11 (1999) 3125]. We have now studied the glial response to the endogenous leech MM peptide (GMGALRL-NH(2), MMHir). The peptide evokes a membrane outward current (EC(50) approximately 2 microM), which neither desensitizes nor shows any sign of run-down, and elicits a K(+) conductance increase of the glial cell membrane. The peptidase inhibitor phenylmethylsulfonyl fluoride (PMSF) enhances the glial current response, suggesting the presence of endogenous extracellular peptidases.
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Affiliation(s)
- Frank C Britz
- Abteilung für Allgemeine Zoologie, FB Biologie, Universität Kaiserslautern, Postfach 3049, D-67653 Kaiserslautern, Germany
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45
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Nässel DR. Neuropeptides in the nervous system of Drosophila and other insects: multiple roles as neuromodulators and neurohormones. Prog Neurobiol 2002; 68:1-84. [PMID: 12427481 DOI: 10.1016/s0301-0082(02)00057-6] [Citation(s) in RCA: 336] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neuropeptides in insects act as neuromodulators in the central and peripheral nervous system and as regulatory hormones released into the circulation. The functional roles of insect neuropeptides encompass regulation of homeostasis, organization of behaviors, initiation and coordination of developmental processes and modulation of neuronal and muscular activity. With the completion of the sequencing of the Drosophila genome we have obtained a fairly good estimate of the total number of genes encoding neuropeptide precursors and thus the total number of neuropeptides in an insect. At present there are 23 identified genes that encode predicted neuropeptides and an additional seven encoding insulin-like peptides in Drosophila. Since the number of G-protein-coupled neuropeptide receptors in Drosophila is estimated to be around 40, the total number of neuropeptide genes in this insect will probably not exceed three dozen. The neuropeptides can be grouped into families, and it is suggested here that related peptides encoded on a Drosophila gene constitute a family and that peptides from related genes (orthologs) in other species belong to the same family. Some peptides are encoded as multiple related isoforms on a precursor and it is possible that many of these isoforms are functionally redundant. The distribution and possible functions of members of the 23 neuropeptide families and the insulin-like peptides are discussed. It is clear that each of the distinct neuropeptides are present in specific small sets of neurons and/or neurosecretory cells and in some cases in cells of the intestine or certain peripheral sites. The distribution patterns vary extensively between types of neuropeptides. Another feature emerging for many insect neuropeptides is that they appear to be multifunctional. One and the same peptide may act both in the CNS and as a circulating hormone and play different functional roles at different central and peripheral targets. A neuropeptide can, for instance, act as a coreleased signal that modulates the action of a classical transmitter and the peptide action depends on the cotransmitter and the specific circuit where it is released. Some peptides, however, may work as molecular switches and trigger specific global responses at a given time. Drosophila, in spite of its small size, is now emerging as a very favorable organism for the studies of neuropeptide function due to the arsenal of molecular genetics methods available.
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Affiliation(s)
- Dick R Nässel
- Department of Zoology, Stockholm University, SE-106 91, Stockholm, Sweden.
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46
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Kean L, Cazenave W, Costes L, Broderick KE, Graham S, Pollock VP, Davies SA, Veenstra JA, Dow JAT. Two nitridergic peptides are encoded by the gene capability in Drosophila melanogaster. Am J Physiol Regul Integr Comp Physiol 2002; 282:R1297-307. [PMID: 11959669 DOI: 10.1152/ajpregu.00584.2001] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A Drosophila gene (capability, capa) at 99D on chromosome 3R potentially encodes three neuropeptides: GANMGLYAFPRV-amide (capa-1), ASGLVAFPRV-amide (capa-2), and TGPSASSGLWGPRL-amide (capa-3). Capa-1 and capa-2 are related to the lepidopteran hormone cardioacceleratory peptide 2b, while capa-3 is a novel member of the pheromone biosynthesis-activating neuropeptide/diapause hormone/pyrokinin family. By immunocytochemistry, we identified four pairs of neuroendocrine cells likely to release the capa peptides into the hemolymph: one pair in the subesophageal ganglion and the other three in the abdominal neuromeres. In the Malpighian (renal) tubule, capa-1 and capa-2 increase fluid secretion rates, stimulate nitric oxide production, and elevate intracellular Ca(2+) and cGMP in principal cells. Capa-stimulated fluid secretion, but not intracellular Ca(2+) concentration rise, is inhibited by the guanylate cyclase inhibitor methylene blue. The actions of capa-1 and capa-2 are not synergistic, implying that both act on the same pathways in tubules. The capa gene is thus the first to be shown to encode neuropeptides that act on renal fluid production through nitric oxide.
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Affiliation(s)
- Laura Kean
- Division of Molecular Genetics, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G11 6NU, United Kingdom
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47
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Abstract
The extremely large number of insects and members of allied groups alive today suggests that molting--shedding of an old cuticle--may be one of the most commonly performed behaviors on our planet. Removal of an old cuticle in insects is associated with stereotyped, species-specific patterns of behavior referred to as ecdysis. It has been recognized for decades that the initiation of ecdysis is under hormonal control, but until recently many of the key peptides that regulate ecdysis were unknown. The report in 1996 of a new ecdysis-triggering hormone (ETH) sparked an era of significant advances in our understanding of the regulation of molting. This article summarizes the current model of peptide regulation of ecdysis, a model that is based on a positive feedback loop between ETH and a brain peptide, eclosion hormone. Then the relationship of these regulatory peptides to the neural circuitry that is the ultimate driver of the behavior are described. Because insects can undergo both status quo (larval-larval) and metamorphic (larval-pupal and pupal-adult) molts, differences in ecdysis behavior at different life stages are described and potential sources of these differences are identified. Most of the work described is based on studies of ecdysis in the hawkmoth, Manduca sexta, but results from studies of ecdysis in the fruit fly Drosophila melanogaster are also discussed.
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Affiliation(s)
- Karen A Mesce
- Department of Entomology, University of Minnesota, St. Paul, Minnesota 55108, USA
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48
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Park Y, Filippov V, Gill SS, Adams ME. Deletion of the ecdysis-triggering hormone gene leads to lethal ecdysis deficiency. Development 2002; 129:493-503. [PMID: 11807040 DOI: 10.1242/dev.129.2.493] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
At the end of each developmental stage, insects perform a stereotypic behavioral sequence leading to ecdysis of the old cuticle. While ecdysis-triggering hormone (ETH) is sufficient to trigger this sequence, it has remained unclear whether it is required. We show that deletion of eth, the gene encoding ETH in Drosophila, leads to lethal behavioral and physiological deficits. Null mutants (eth–) fail to inflate the new respiratory system on schedule, do not perform the ecdysis behavioral sequence, and exhibit the phenotype buttoned-up, which is characterized by incomplete ecdysis and 98% mortality at the transition from first to second larval instar. Precisely timed injection of synthetic DmETH1 restores all deficits and allows normal ecdysis to occur. These findings establish obligatory roles for eth and its gene products in initiation and regulation of the ecdysis sequence. The ETH signaling system provides an opportunity for genetic analysis of a chemically coded physiological and behavioral sequence.
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Affiliation(s)
- Yoonseong Park
- Department of Entomology, 5429 Boyce Hall, University of California, Riverside, CA 92521, USA
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Jiang N, Kolhekar AS, Jacobs PS, Mains RE, Eipper BA, Taghert PH. PHM is required for normal developmental transitions and for biosynthesis of secretory peptides in Drosophila. Dev Biol 2000; 226:118-36. [PMID: 10993678 DOI: 10.1006/dbio.2000.9832] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To understand the roles of secretory peptides in developmental signaling, we have studied Drosophila mutant for the gene peptidylglycine alpha-hydroxylating monooxygenase (PHM). PHM is the rate-limiting enzyme for C-terminal alpha-amidation, a specific and necessary modification of secretory peptides. In insects, more than 90% of known or predicted neuropeptides are amidated. PHM mutants lack PHM protein and enzyme activity; most null animals die as late embryos with few morphological defects. Natural and synthetic PHM hypomorphs revealed phenotypes that resembled those of animals with mutations in genes of the ecdysone-inducible regulatory circuit. Animals bearing a strong hypomorphic allele contain no detectable PHM enzymatic activity or protein; approximately 50% hatch and initially display normal behavior, then die as young larvae, often while attempting to molt. PHM mutants were rescued with daily induction of a PHM transgene and complete rescue was seen with induction limited to the first 4 days after egg-laying. The rescued mutant adults produced progeny which survived to various stages up through metamorphosis (synthetic hypomorphs) and displayed prepupal and pupal phenotypes resembling those of ecdysone-response gene mutations. Examination of neuropeptide biosynthesis in PHM mutants revealed specific disruptions: Amidated peptides were largely absent in strong hypomorphs, but peptide precursors, a nonamidated neuropeptide, nonpeptide transmitters, and other peptide biosynthetic enzymes were readily detected. Mutant adults that were produced by a minimal rescue schedule had lowered PHM enzyme levels and reproducibly altered patterns of amidated neuropeptides in the CNS. These deficits were partially reversed within 24 h by a single PHM induction in the adult stage. These genetic results support the hypothesis that secretory peptide signaling is critical for transitions between developmental stages, without strongly affecting morphogenetic events within a stage. Further, they show that PHM is required for peptide alpha-amidating activity throughout the life of Drosophila. Finally, they define novel methods to study neural and endocrine peptide biosynthesis and functions in vivo.
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Affiliation(s)
- N Jiang
- Department of Anatomy & Neurobiology, Washington University School of Medicine, Saint Louis 63130, USA
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Hewes RS, Schaefer AM, Taghert PH. The cryptocephal gene (ATF4) encodes multiple basic-leucine zipper proteins controlling molting and metamorphosis in Drosophila. Genetics 2000; 155:1711-23. [PMID: 10924469 PMCID: PMC1461179 DOI: 10.1093/genetics/155.4.1711] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The cryptocephal (crc) mutation causes pleiotropic defects in ecdysone-regulated events during Drosophila molting and metamorphosis. Here we report that crc encodes a Drosophila homolog of vertebrate ATF4, a member of the CREB/ATF family of basic-leucine zipper (bZIP) transcription factors. We identified three putative protein isoforms. CRC-A and CRC-B contain the bZIP domain, and CRC-D is a C-terminally truncated form. We have generated seven new crc alleles. Consistent with the molecular diversity of crc, these alleles show that crc is a complex genetic locus with two overlapping lethal complementation groups. Alleles representing both groups were rescued by a cDNA encoding CRC-B. One lethal group (crc(1), crc(R6), and crc(Rev8)) consists of strong hypomorphic or null alleles that are associated with mutations of both CRC-A and CRC-B. These mutants display defects associated with larval molting and pupariation. In addition, they fail to evert the head and fail to elongate the imaginal discs during pupation, and they display variable defects in the subsequent differentiation of the adult abdomen. The other group (crc(R1), crc(R2), crc(E85), crc(E98), and crc(929)) is associated with disruptions of CRC-A and CRC-D; except for a failure to properly elongate the leg discs, these mutants initiate metamorphosis normally. Subsequently, they display a novel metamorphic phenotype, involving collapse of the head and abdomen toward the thorax. The crc gene is expressed throughout development and in many tissues. In third instar larvae, crc expression is high in targets of ecdysone signaling, such as the leg and wing imaginal discs, and in the ring gland, the source of ecdysone. Together, these findings implicate CREB/ATF proteins in essential functions during molting and metamorphosis. In addition, the similarities between the mutant phenotypes of crc and the ecdysone-responsive genes indicate that these genes are likely to be involved in common signaling pathways.
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Affiliation(s)
- R S Hewes
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri 63110, USA.
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