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Halberg KV, Denholm B. Mechanisms of Systemic Osmoregulation in Insects. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:415-438. [PMID: 37758224 DOI: 10.1146/annurev-ento-040323-021222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Water is essential to life. Terrestrial insects lose water by evaporation from the body surface and respiratory surfaces, as well as in the excretory products, posing a challenge made more acute by their high surface-to-volume ratio. These losses must be kept to a minimum and be offset by water gained from other sources. By contrast, insects such as the blood-sucking bug Rhodnius prolixus consume up to 10 times their body weight in a single blood meal, necessitating rapid expulsion of excess water and ions. How do insects manage their ion and water budgets? A century of study has revealed a great deal about the organ systems that insects use to maintain their ion and water balance and their regulation. Traditionally, a taxonomically wide range of species were studied, whereas more recent research has focused on model organisms to leverage the power of the molecular genetic approach. Key advances in new technologies have become available for a wider range of species in the past decade. We document how these approaches have already begun to inform our understanding of the diversity and conservation of insect systemic osmoregulation. We advocate that these technologies be combined with traditional approaches to study a broader range of nonmodel species to gain a comprehensive overview of the mechanism underpinning systemic osmoregulation in the most species-rich group of animals on earth, the insects.
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Affiliation(s)
- Kenneth Veland Halberg
- Section for Cell and Neurobiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark;
| | - Barry Denholm
- Department of Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
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2
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Okamoto N, Watanabe A. Interorgan communication through peripherally derived peptide hormones in Drosophila. Fly (Austin) 2022; 16:152-176. [PMID: 35499154 PMCID: PMC9067537 DOI: 10.1080/19336934.2022.2061834] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In multicellular organisms, endocrine factors such as hormones and cytokines regulate development and homoeostasis through communication between different organs. For understanding such interorgan communications through endocrine factors, the fruit fly Drosophila melanogaster serves as an excellent model system due to conservation of essential endocrine systems between flies and mammals and availability of powerful genetic tools. In Drosophila and other insects, functions of neuropeptides or peptide hormones from the central nervous system have been extensively studied. However, a series of recent studies conducted in Drosophila revealed that peptide hormones derived from peripheral tissues also play critical roles in regulating multiple biological processes, including growth, metabolism, reproduction, and behaviour. Here, we summarise recent advances in understanding target organs/tissues and functions of peripherally derived peptide hormones in Drosophila and describe how these hormones contribute to various biological events through interorgan communications.
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Affiliation(s)
- Naoki Okamoto
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Akira Watanabe
- Degree Programs in Life and Earth Sciences, Graduate School of Science and Technology, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Diesner M, Bläser M, Eckardt S, Iliffe TM, Boelen Theile E, Predel R. Expression pattern of CAPA/pyrokinin neuropeptide genes in Remipedia and silverfish: Rapid differentiation after gene duplication in early Hexapoda, followed by strong conservation of newly established features in insects. Peptides 2021; 144:170610. [PMID: 34242680 DOI: 10.1016/j.peptides.2021.170610] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/27/2021] [Accepted: 07/01/2021] [Indexed: 12/15/2022]
Abstract
Only few genes are known from insects that encode multiple neuropeptides, i.e., peptides that activate different receptors. Among those are the capa and pk genes, which differentiated within Hexapoda following gene duplication. In our study, we focus on the early stages of differentiation of these genes. Specifically: (1) What was the expression pattern of the ancestral capa/pk gene, i.e., prior to gene duplication? (2) What is the expression pattern of capa and pk in silverfish, whose ancestors diverged from Pterygota more than 400 mya? Our results suggest the location and projection of CAPA immunoreactive Va cells in abdominal ganglia (trunk ganglia in Remipedia) are a plesiomorphic trait that was already present in the ancestor of Remipedia and Hexapoda. General features of serial homology such as location of cells bodies, contralateral projection of primary neurites, and presumed peripheral peptide release from segmentally arranged neurohemal release sites could be observed in Remipedia and silverfish, but also in all Pterygota studied so far. Differences are mainly in the specific location of these peripheral release sites. This hypothetical basic pattern of capa/pk neurons underwent modifications in the anterior ganglia of the ventral nerve cord already in Remipedia. In silverfish, as in all Pterygota studied so far, pk expression in the CNS is apparently restricted to the gnathal ganglia, whereas capa expression is typical of abdominal Va cells. Thus, differentiation in the expression pattern of capa and pk genes occurred early in the evolution of Hexapoda; likely soon after the appearance of two separate genes.
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Affiliation(s)
- Max Diesner
- Department of Biology, Institute of Zoology, University of Cologne, D-50674, Cologne, Germany
| | - Marcel Bläser
- Department of Biology, Institute of Zoology, University of Cologne, D-50674, Cologne, Germany
| | - Sarah Eckardt
- Department of Biology, Institute of Zoology, University of Cologne, D-50674, Cologne, Germany
| | - Thomas M Iliffe
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, 77554, USA
| | - Erik Boelen Theile
- Department of Biology, Institute of Zoology, University of Cologne, D-50674, Cologne, Germany
| | - Reinhard Predel
- Department of Biology, Institute of Zoology, University of Cologne, D-50674, Cologne, Germany.
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4
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A nutrient-responsive hormonal circuit mediates an inter-tissue program regulating metabolic homeostasis in adult Drosophila. Nat Commun 2021; 12:5178. [PMID: 34462441 PMCID: PMC8405823 DOI: 10.1038/s41467-021-25445-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 08/04/2021] [Indexed: 02/07/2023] Open
Abstract
Animals maintain metabolic homeostasis by modulating the activity of specialized organs that adjust internal metabolism to external conditions. However, the hormonal signals coordinating these functions are incompletely characterized. Here we show that six neurosecretory cells in the Drosophila central nervous system respond to circulating nutrient levels by releasing Capa hormones, homologs of mammalian neuromedin U, which activate the Capa receptor (CapaR) in peripheral tissues to control energy homeostasis. Loss of Capa/CapaR signaling causes intestinal hypomotility and impaired nutrient absorption, which gradually deplete internal nutrient stores and reduce organismal lifespan. Conversely, increased Capa/CapaR activity increases fluid and waste excretion. Furthermore, Capa/CapaR inhibits the release of glucagon-like adipokinetic hormone from the corpora cardiaca, which restricts energy mobilization from adipose tissue to avoid harmful hyperglycemia. Our results suggest that the Capa/CapaR circuit occupies a central node in a homeostatic program that facilitates the digestion and absorption of nutrients and regulates systemic energy balance.
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Zandawala M, Nguyen T, Balanyà Segura M, Johard HAD, Amcoff M, Wegener C, Paluzzi JP, Nässel DR. A neuroendocrine pathway modulating osmotic stress in Drosophila. PLoS Genet 2021; 17:e1009425. [PMID: 33684132 PMCID: PMC7971876 DOI: 10.1371/journal.pgen.1009425] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 03/18/2021] [Accepted: 02/15/2021] [Indexed: 12/19/2022] Open
Abstract
Environmental factors challenge the physiological homeostasis in animals, thereby evoking stress responses. Various mechanisms have evolved to counter stress at the organism level, including regulation by neuropeptides. In recent years, much progress has been made on the mechanisms and neuropeptides that regulate responses to metabolic/nutritional stress, as well as those involved in countering osmotic and ionic stresses. Here, we identified a peptidergic pathway that links these types of regulatory functions. We uncover the neuropeptide Corazonin (Crz), previously implicated in responses to metabolic stress, as a neuroendocrine factor that inhibits the release of a diuretic hormone, CAPA, and thereby modulates the tolerance to osmotic and ionic stress. Both knockdown of Crz and acute injections of Crz peptide impact desiccation tolerance and recovery from chill-coma. Mapping of the Crz receptor (CrzR) expression identified three pairs of Capa-expressing neurons (Va neurons) in the ventral nerve cord that mediate these effects of Crz. We show that Crz acts to restore water/ion homeostasis by inhibiting release of CAPA neuropeptides via inhibition of cAMP production in Va neurons. Knockdown of CrzR in Va neurons affects CAPA signaling, and consequently increases tolerance for desiccation, ionic stress and starvation, but delays chill-coma recovery. Optogenetic activation of Va neurons stimulates excretion and simultaneous activation of Crz and CAPA-expressing neurons reduces this response, supporting the inhibitory action of Crz. Thus, Crz inhibits Va neurons to maintain osmotic and ionic homeostasis, which in turn affects stress tolerance. Earlier work demonstrated that systemic Crz signaling restores nutrient levels by promoting food search and feeding. Here we additionally propose that Crz signaling also ensures osmotic homeostasis by inhibiting release of CAPA neuropeptides and suppressing diuresis. Thus, Crz ameliorates stress-associated physiology through systemic modulation of both peptidergic neurosecretory cells and the fat body in Drosophila.
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Affiliation(s)
- Meet Zandawala
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Thomas Nguyen
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Marta Balanyà Segura
- Neurobiology and Genetics, Würzburg Insect Research (WIR), Theodor-Boveri-Institute, Biocenter, University of Würzburg, Germany
| | | | - Mirjam Amcoff
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Christian Wegener
- Neurobiology and Genetics, Würzburg Insect Research (WIR), Theodor-Boveri-Institute, Biocenter, University of Würzburg, Germany
| | | | - Dick R Nässel
- Department of Zoology, Stockholm University, Stockholm, Sweden
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6
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Sajadi F, Uyuklu A, Paputsis C, Lajevardi A, Wahedi A, Ber LT, Matei A, Paluzzi JPV. CAPA neuropeptides and their receptor form an anti-diuretic hormone signaling system in the human disease vector, Aedes aegypti. Sci Rep 2020; 10:1755. [PMID: 32020001 PMCID: PMC7000730 DOI: 10.1038/s41598-020-58731-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/20/2020] [Indexed: 01/07/2023] Open
Abstract
Insect CAPA neuropeptides are homologs of mammalian neuromedin U and are known to influence ion and water balance by regulating the activity of the Malpighian 'renal' tubules (MTs). Several diuretic hormones are known to increase primary fluid and ion secretion by insect MTs and, in adult female mosquitoes, a calcitonin-related peptide (DH31) called mosquito natriuretic peptide, increases sodium secretion to compensate for the excess salt load acquired during blood-feeding. An endogenous mosquito anti-diuretic hormone was recently described, having potent inhibitory activity against select diuretic hormones, including DH31. Herein, we functionally deorphanized, both in vitro and in vivo, a mosquito anti-diuretic hormone receptor (AedaeADHr) with expression analysis indicating highest enrichment in the MTs where it is localized within principal cells. Characterization using a heterologous in vitro system demonstrated the receptor was highly sensitive to mosquito CAPA neuropeptides while in vivo, AedaeADHr knockdown abolished CAPA-induced anti-diuretic control of DH31-stimulated MTs. CAPA neuropeptides are produced within a pair of neurosecretory cells in each of the abdominal ganglia, whose axonal projections innervate the abdominal neurohaemal organs, where these neurohormones are released into circulation. Lastly, pharmacological inhibition of nitric oxide synthase (NOS) and protein kinase G (PKG) signaling eliminated anti-diuretic activity of CAPA, highlighting the role of the second messenger cGMP and NOS/PKG in this anti-diuretic signaling pathway.
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Affiliation(s)
- Farwa Sajadi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Ali Uyuklu
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Christine Paputsis
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Aryan Lajevardi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Azizia Wahedi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Lindsay Taylor Ber
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Andreea Matei
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Jean-Paul V Paluzzi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada.
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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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8
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Ohhara Y, Kobayashi S, Yamakawa-Kobayashi K, Yamanaka N. Adult-specific insulin-producing neurons in Drosophila melanogaster. J Comp Neurol 2018; 526:1351-1367. [PMID: 29424424 DOI: 10.1002/cne.24410] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/30/2018] [Accepted: 01/30/2018] [Indexed: 12/19/2022]
Abstract
Holometabolous insects undergo metamorphosis to reorganize their behavioral and morphological features into adult-specific ones. In the central nervous system (CNS), some larval neurons undergo programmed cell death, whereas others go through remodeling of axonal and dendritic arbors to support functions of re-established adult organs. Although there are multiple neuropeptides that have stage-specific roles in holometabolous insects, the reorganization pattern of the entire neuropeptidergic system through metamorphosis still remains largely unclear. In this study, we conducted a mapping and lineage tracing of peptidergic neurons in the larval and adult CNS by using Drosophila genetic tools. We found that Diuretic hormone 44-producing median neurosecretory cells start expressing Insulin-like peptide 2 in the pharate adult stage. This neuronal cluster projects to the corpora cardiaca and dorsal vessel in both larval and adult stages, and also innervates an adult-specific structure in the digestive tract, the crop. We propose that the adult-specific insulin-producing cells may regulate functions of the digestive system in a stage-specific manner. Our study provides a neuroanatomical basis for understanding remodeling of the neuropeptidergic system during insect development and evolution.
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Affiliation(s)
- Yuya Ohhara
- School of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Satoru Kobayashi
- Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Kimiko Yamakawa-Kobayashi
- School of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Naoki Yamanaka
- Department of Entomology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, California
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Ng YS, Sorvina A, Bader CA, Weiland F, Lopez AF, Hoffmann P, Shandala T, Brooks DA. Proteome Analysis of Drosophila Mutants Identifies a Regulatory Role for 14-3-3ε in Metabolic Pathways. J Proteome Res 2017; 16:1976-1987. [PMID: 28365999 DOI: 10.1021/acs.jproteome.6b01032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The evolutionary conserved family of 14-3-3 proteins appears to have a role in integrating numerous intracellular pathways, including signal transduction, intracellular trafficking, and metabolism. However, little is known about how this interactive network might be affected by the direct abrogation of 14-3-3 function. The loss of Drosophila 14-3-3ε resulted in reduced survival of mutants during larval-to-adult transition, which is known to depend on an energy supply coming from the histolysis of fat body tissue. Here we report a differential proteomic analysis of larval fat body tissue at the onset of larval-to-adult transition, with the loss of 14-3-3ε resulting in the altered abundance of 16 proteins. These included proteins linked to protein biosynthesis, glycolysis, tricarboxylic acid cycle, and lipid metabolic pathways. The ecdysone receptor (EcR), which is responsible for initiating the larval-to-adult transition, colocalized with 14-3-3ε in wild-type fat body tissues. The altered protein abundance in 14-3-3ε mutant fat body tissue was associated with transcriptional deregulation of alcohol dehydrogenase, fat body protein 1, and lamin genes, which are known targets of the EcR. This study indicates that 14-3-3ε has a critical role in cellular metabolism involving either molecular crosstalk with the EcR or direct interaction with metabolic proteins.
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Affiliation(s)
- Yeap S Ng
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia , Adelaide, South Australia 5001, Australia
| | - Alexandra Sorvina
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia , Adelaide, South Australia 5001, Australia
| | - Christie A Bader
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia , Adelaide, South Australia 5001, Australia
| | - Florian Weiland
- Adelaide Proteomics Center, School of Molecular and Biomedical Sciences, University of Adelaide , Adelaide, South Australia 5005, Australia
| | - Angel F Lopez
- Centre for Cancer Biology , Adelaide, South Australia 5000, Australia
| | - Peter Hoffmann
- Adelaide Proteomics Center, School of Molecular and Biomedical Sciences, University of Adelaide , Adelaide, South Australia 5005, Australia
| | | | - Douglas A Brooks
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia , Adelaide, South Australia 5001, Australia
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Morphological and Transcriptomic Analysis of a Beetle Chemosensory System Reveals a Gnathal Olfactory Center. BMC Biol 2016; 14:90. [PMID: 27751175 PMCID: PMC5067906 DOI: 10.1186/s12915-016-0304-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/05/2016] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The red flour beetle Tribolium castaneum is an emerging insect model organism representing the largest insect order, Coleoptera, which encompasses several serious agricultural and forest pests. Despite the ecological and economic importance of beetles, most insect olfaction studies have so far focused on dipteran, lepidopteran, or hymenopteran systems. RESULTS Here, we present the first detailed morphological description of a coleopteran olfactory pathway in combination with genome-wide expression analysis of the relevant gene families involved in chemoreception. Our study revealed that besides the antennae, also the mouthparts are highly involved in olfaction and that their respective contribution is processed separately. In this beetle, olfactory sensory neurons from the mouthparts project to the lobus glomerulatus, a structure so far only characterized in hemimetabolous insects, as well as to a so far non-described unpaired glomerularly organized olfactory neuropil in the gnathal ganglion, which we term the gnathal olfactory center. The high number of functional odorant receptor genes expressed in the mouthparts also supports the importance of the maxillary and labial palps in olfaction of this beetle. Moreover, gustatory perception seems equally distributed between antenna and mouthparts, since the number of expressed gustatory receptors is similar for both organs. CONCLUSIONS Our analysis of the T. castaneum chemosensory system confirms that olfactory and gustatory perception are not organotopically separated to the antennae and mouthparts, respectively. The identification of additional olfactory processing centers, the lobus glomerulatus and the gnathal olfactory center, is in contrast to the current picture that in holometabolous insects all olfactory inputs allegedly converge in the antennal lobe. These findings indicate that Holometabola have evolved a wider variety of solutions to chemoreception than previously assumed.
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Identification of two capa cDNA transcripts and detailed peptidomic characterization of their peptide products in Periplaneta americana. EUPA OPEN PROTEOMICS 2014. [DOI: 10.1016/j.euprot.2014.02.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Choi MY, Köhler R, Vander Meer RK, Neupert S, Predel R. Identification and expression of capa gene in the fire ant, Solenopsis invicta. PLoS One 2014; 9:e94274. [PMID: 24718032 PMCID: PMC3981796 DOI: 10.1371/journal.pone.0094274] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 03/14/2014] [Indexed: 11/18/2022] Open
Abstract
Recent genome analyses suggested the absence of a number of neuropeptide genes in ants. One of the apparently missing genes was the capa gene. Capa gene expression in insects is typically associated with the neuroendocrine system of abdominal ganglia; mature CAPA peptides are known to regulate diuresis and visceral muscle contraction. The apparent absence of the capa gene raised questions about possible compensation of these functions. In this study, we re-examined this controversial issue and searched for a potentially unrecognized capa gene in the fire ant, Solenopsis invicta. We employed a combination of data mining and a traditional PCR-based strategy using degenerate primers designed from conserved amino acid sequences of insect capa genes. Our findings demonstrate that ants possess and express a capa gene. As shown by MALDI-TOF mass spectrometry, processed products of the S. invicta capa gene include three CAPA periviscerokinins and low amounts of a pyrokinin which does not have the C-terminal WFGPRLa motif typical of CAPA pyrokinins in other insects. The capa gene was found with two alternative transcripts in the CNS. Within the ventral nerve cord, two capa neurons were immunostained in abdominal neuromeres 2–5, respectively, and projected into ventrally located abdominal perisympathetic organs (PSOs), which are the major hormone release sites of abdominal ganglia. The ventral location of these PSOs is a characteristic feature and was also found in another ant, Atta sexdens.
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Affiliation(s)
- Man-Yeon Choi
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center of Medical, Agricultural and Veterinary Entomology (CMAVE), Gainesville, Florida, United States of America
- * E-mail: (MYC); (RP)
| | - Rene Köhler
- Zoological Institute, Biocenter University of Cologne, Cologne, Germany
| | - Robert K. Vander Meer
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center of Medical, Agricultural and Veterinary Entomology (CMAVE), Gainesville, Florida, United States of America
| | - Susanne Neupert
- Zoological Institute, Biocenter University of Cologne, Cologne, Germany
| | - Reinhard Predel
- Zoological Institute, Biocenter University of Cologne, Cologne, Germany
- * E-mail: (MYC); (RP)
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Karsai G, Pollák E, Wacker M, Vömel M, Selcho M, Berta G, Nachman RJ, Isaac RE, Molnár L, Wegener C. Diverse in- and output polarities and high complexity of local synaptic and non-synaptic signaling within a chemically defined class of peptidergic Drosophila neurons. Front Neural Circuits 2013; 7:127. [PMID: 23914156 PMCID: PMC3729985 DOI: 10.3389/fncir.2013.00127] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/12/2013] [Indexed: 12/31/2022] Open
Abstract
Peptidergic neurons are not easily integrated into current connectomics concepts, since their peptide messages can be distributed via non-synaptic paracrine signaling or volume transmission. Moreover, the polarity of peptidergic interneurons in terms of in- and out-put sites can be hard to predict and is very little explored. We describe in detail the morphology and the subcellular distribution of fluorescent vesicle/dendrite markers in CCAP neurons (NCCAP), a well defined set of peptidergic neurons in the Drosophila larva. NCCAP can be divided into five morphologically distinct subsets. In contrast to other subsets, serial homologous interneurons in the ventral ganglion show a mixed localization of in- and output markers along ventral neurites that defy a classification as dendritic or axonal compartments. Ultrastructurally, these neurites contain both pre- and postsynaptic sites preferably at varicosities. A significant portion of the synaptic events are due to reciprocal synapses. Peptides are mostly non-synaptically or parasynaptically released, and dense-core vesicles and synaptic vesicle pools are typically well separated. The responsiveness of the NCCAP to ecdysis-triggering hormone may be at least partly dependent on a tonic synaptic inhibition, and is independent of ecdysteroids. Our results reveal a remarkable variety and complexity of local synaptic circuitry within a chemically defined set of peptidergic neurons. Synaptic transmitter signaling as well as peptidergic paracrine signaling and volume transmission from varicosities can be main signaling modes of peptidergic interneurons depending on the subcellular region. The possibility of region-specific variable signaling modes should be taken into account in connectomic studies that aim to dissect the circuitry underlying insect behavior and physiology, in which peptidergic neurons act as important regulators.
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Affiliation(s)
- Gergely Karsai
- Department of Comparative Anatomy and Developmental Biology, Institute of Biology, Faculty of Science, University of Pécs Pécs, Hungary ; Neurobiology and Genetics, Biocenter, Theodor-Boveri-Institute, University of Würzburg Würzburg, Germany
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14
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Rahman MM, Neupert S, Predel R. Neuropeptidomics of the Australian sheep blowfly Lucilia cuprina (Wiedemann) and related Diptera. Peptides 2013; 41:31-7. [PMID: 23280433 DOI: 10.1016/j.peptides.2012.12.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/21/2012] [Accepted: 12/21/2012] [Indexed: 01/13/2023]
Abstract
Insect neuropeptides are the most diverse and important group of messenger molecules that regulate almost all physiological processes, including behavior. In this study, we performed a combination of matrix assisted laser desorption ionization time of flight (MALDI-TOF) and electrospray ionization quadrupole time of flight (ESI-Q-TOF) mass spectrometry to analyze the peptidome of the brain and the neurohemal organs of the Australian sheep blowfly Lucilia cuprina and compared the data with those of related flies such as the gray flesh fly Sarcophaga (=Neobellieria) bullata; the cabbage root fly Delia radicum, the fruit fly Drosophila melanogaster, and the yellow fever mosquito, Aedes aegypti. Without counting low intensity signals of truncated peptides, 45 neuropeptides arising from 12 neuropeptide genes (adipokinetic hormone, CAPA-peptides, corazonin, extended FMRFamides, SIFamide, insect kinin, short neuropeptide F, NPLP-1 peptides, HUGIN-pyrokinin, sulfakinins, allatostatins A, putative eclosion hormone precursor peptide) were identified; sequences of extended FMRFamides were reported in a separate publication. The remarkable similarity of the peptidome of cyclorraphan flies, which contain a large number of ecologically important species, does not support the development of a species-specific neuropeptide-based insect pest control strategy. However, mass spectrometric approaches as shown here do not cover the entire peptidome or differences at the receptor level and it is possible that group-specific peptide ligands or receptors exist that escaped the detection.
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Affiliation(s)
- Mohammad Mazibur Rahman
- Department of General Zoology and Animal Physiology, Friedrich-Schiller-University, Jena, Germany
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15
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Predel R, Neupert S, Russell WK, Hauser F, Russell DH, Li A, Nachman RJ. CAPA-gene products in the haematophagous sandfly Phlebotomus papatasi (Scopoli)--vector for leishmaniasis disease. Peptides 2013; 41:2-7. [PMID: 23266568 DOI: 10.1016/j.peptides.2012.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 12/07/2012] [Accepted: 12/10/2012] [Indexed: 11/20/2022]
Abstract
Sandflies (Phlebotominae, Nematocera, Diptera) are responsible for transmission of leishmaniasis and other protozoan-borne diseases in humans, and these insects depend on the regulation of water balance to cope with the sudden and enormous intake of blood over a very short time period. The sandfly inventory of neuropeptides, including those that regulate diuretic processes, is completely unknown. Direct MALDI-TOF/TOF mass spectrometric analysis of dissected ganglia of Phlebotomus papatasi, combined with a data-mining of sandfly genome 'contigs', was used to identify native CAPA-peptides, a peptide class associated with the regulation of diuresis in other hematophagous insects. The CAPA-peptides identified in this study include two CAPA-PVKs, differentially processed CAPA-PK, and an additional CAPA precursor peptide. The mass spectrometric analysis of different parts of the neuroendocrine system of the sandfly indicate that it represents the first insect which accumulates CAPA-PVKs exclusively in hormone release sites of abdominal ganglia and CAPA-PK (nearly) exclusively in the corpora cardiaca. Additionally, sandflies feature the smallest abdominal ganglia (~35 μm) where CAPA-peptides could be detected so far. The small size of the abdominal ganglia does not appear to affect the development of the median neurosecretory system as it obviously does in another comparably small insect species, Nasonia vitripennis, in which no capa-gene expression was found. Rather, immunocytochemical analyses confirm that the general architecture in sandflies appears identical to that of much larger mosquitoes.
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Affiliation(s)
- Reinhard Predel
- Zoological Institute, Biocenter University of Cologne, Cologne, Germany.
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16
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Zoephel J, Reiher W, Rexer KH, Kahnt J, Wegener C. Peptidomics of the agriculturally damaging larval stage of the cabbage root fly Delia radicum (Diptera: Anthomyiidae). PLoS One 2012; 7:e41543. [PMID: 22848525 PMCID: PMC3405134 DOI: 10.1371/journal.pone.0041543] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 06/22/2012] [Indexed: 12/01/2022] Open
Abstract
The larvae of the cabbage root fly induce serious damage to cultivated crops of the family Brassicaceae. We here report the biochemical characterisation of neuropeptides from the central nervous system and neurohemal organs, as well as regulatory peptides from enteroendocrine midgut cells of the cabbage maggot. By LC-MALDI-TOF/TOF and chemical labelling with 4-sulfophenyl isothiocyanate, 38 peptides could be identified, representing major insect peptide families: allatostatin A, allatostatin C, FMRFamide-like peptides, kinin, CAPA peptides, pyrokinins, sNPF, myosuppressin, corazonin, SIFamide, sulfakinins, tachykinins, NPLP1-peptides, adipokinetic hormone and CCHamide 1. We also report a new peptide (Yamide) which appears to be homolog to an amidated eclosion hormone-associated peptide in several Drosophila species. Immunocytochemical characterisation of the distribution of several classes of peptide-immunoreactive neurons and enteroendocrine cells shows a very similar but not identical peptide distribution to Drosophila. Since peptides regulate many vital physiological and behavioural processes such as moulting or feeding, our data may initiate the pharmacological testing and development of new specific peptide-based protection methods against the cabbage root fly and its larva.
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Affiliation(s)
- Judith Zoephel
- Department of Biology, Animal Physiology, Philipps-University Marburg, Marburg, Germany
| | - Wencke Reiher
- Department of Biology, Animal Physiology, Philipps-University Marburg, Marburg, Germany
- Neurobiology and Genetics, Theodor Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Karl-Heinz Rexer
- Department of Biology, Mycology, Philipps-University Marburg, Marburg, Germany
| | - Jörg Kahnt
- Max-Planck-Institute of Terrestrial Microbiology, Marburg, Germany
| | - Christian Wegener
- Department of Biology, Animal Physiology, Philipps-University Marburg, Marburg, Germany
- Neurobiology and Genetics, Theodor Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
- * E-mail:
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Srinivasan S, Lance K, Levine RB. Segmental differences in firing properties and potassium currents in Drosophila larval motoneurons. J Neurophysiol 2011; 107:1356-65. [PMID: 22157123 DOI: 10.1152/jn.00200.2011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Potassium currents play key roles in regulating motoneuron activity, including functional specializations that are important for locomotion. The thoracic and abdominal segments in the Drosophila larval ganglion have repeated arrays of motoneurons that innervate body-wall muscles used for peristaltic movements during crawling. Although abdominal motoneurons and their muscle targets have been studied in detail, owing, in part, to their involvement in locomotion, little is known about the cellular properties of motoneurons in thoracic segments. The goal of this study was to compare firing properties among thoracic motoneurons and the potassium currents that influence them. Whole-cell, patch-clamp recordings performed from motoneurons in two thoracic and one abdominal segment revealed both transient and sustained voltage-activated K(+) currents, each with Ca(++)-sensitive and Ca(++)-insensitive [A-type, voltage-dependent transient K(+) current (I(Av))] components. Segmental differences in the expression of voltage-activated K(+) currents were observed. In addition, we demonstrate that Shal contributes to I(Av) currents in the motoneurons of the first thoracic segment.
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Isoform-specific regulation of a steroid hormone nuclear receptor by an E3 ubiquitin ligase in Drosophila melanogaster. Genetics 2011; 189:871-83. [PMID: 21900267 DOI: 10.1534/genetics.111.132191] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The steroid hormone 20-hydroxyecdysone (20E) regulates gene transcription through the heterodimeric nuclear receptor composed of ecdysone receptor (EcR) and Ultraspiracle (USP). The EcR gene encodes three protein isoforms--A, B1, and B2--with variant N-terminal domains that mediate tissue and developmental stage-specific responses to 20E. Ariadne-1a is a conserved member of the RING finger family of ubiquitin ligases first identified in Drosophila melanogaster. Loss-of-function mutations at key cysteines in either of the two RING finger motifs, as well as general overexpression of this enzyme, cause lethality in pupae, which suggests a requirement in metamorphosis. Here, we show that Ariadne-1a binds specifically the isoform A of EcR and ubiquitylates it. Co-immunoprecipitation experiments indicate that the full sequence of EcRA is required for this binding. Protein levels of EcRA and USP change in opposite directions when those of ARI-1a are genetically altered. This is an isoform-specific, E3-dependent regulatory mechanism for a steroid nuclear receptor. Further, qRT-PCR experiments show that the ARI-1a levels lead to the transcriptional regulation of Eip78C, Eip74EF, Eip75B, and Br-C, as well as that of EcR and usp genes. Thus, the activity of this enzyme results in the regulation of dimerizing receptors at the protein and gene transcription levels. This fine-tuned orchestration by a conserved ubiquitin ligase is required during insect metamorphosis and, likely, in other steroid hormone-controlled processes across species.
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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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20
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Wegener C, Herbert H, Kahnt J, Bender M, Rhea JM. Deficiency of prohormone convertase dPC2 (AMONTILLADO) results in impaired production of bioactive neuropeptide hormones in Drosophila. J Neurochem 2011; 118:581-95. [PMID: 21138435 DOI: 10.1111/j.1471-4159.2010.07130.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Christian Wegener
- Department of Biology, Animal Physiology, Philipps-University, Marburg, Germany.
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Gabilondo H, Losada-Pérez M, del Saz D, Molina I, León Y, Canal I, Torroja L, Benito-Sipos J. A targeted genetic screen identifies crucial players in the specification of the Drosophila abdominal Capaergic neurons. Mech Dev 2011; 128:208-21. [PMID: 21236339 DOI: 10.1016/j.mod.2011.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 12/01/2010] [Accepted: 01/05/2011] [Indexed: 01/29/2023]
Abstract
The central nervous system contains a wide variety of neuronal subclasses generated by neural progenitors. The achievement of a unique neural fate is the consequence of a sequence of early and increasingly restricted regulatory events, which culminates in the expression of a specific genetic combinatorial code that confers individual characteristics to the differentiated cell. How the earlier regulatory events influence post-mitotic cell fate decisions is beginning to be understood in the Drosophila NB 5-6 lineage. However, it remains unknown to what extent these events operate in other lineages. To better understand this issue, we have used a very highly specific marker that identifies a small subset of abdominal cells expressing the Drosophila neuropeptide Capa: the ABCA neurons. Our data support the birth of the ABCA neurons from NB 5-3 in a cas temporal window in the abdominal segments A2-A4. Moreover, we show that the ABCA neuron has an ABCA-sibling cell which dies by apoptosis. Surprisingly, both cells are also generated in the abdominal segments A5-A7, although they undergo apoptosis before expressing Capa. In addition, we have performed a targeted genetic screen to identify players involved in ABCA specification. We have found that the ABCA fate requires zfh2, grain, Grunge and hedgehog genes. Finally, we show that the NB 5-3 generates other subtype of Capa-expressing cells (SECAs) in the third suboesophageal segment, which are born during a pdm/cas temporal window, and have different genetic requirements for their specification.
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Affiliation(s)
- Hugo Gabilondo
- Departamento de Biología, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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22
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Wegener C, Neupert S, Predel R. Direct MALDI-TOF mass spectrometric peptide profiling of neuroendocrine tissue of Drosophila. Methods Mol Biol 2010; 615:117-27. [PMID: 20013204 DOI: 10.1007/978-1-60761-535-4_9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Direct MALDI-TOF mass spectrometric peptide profiling is increasingly used to analyze the peptide complement in the nervous system of a variety of invertebrate animals, from leech to Aplysia and many arthropod species, especially insects and crustaceans. Proper sample preparation is often the most crucial step to obtain the necessary data. Here, we describe protocols for the use of MALDI-TOF mass spectrometry to directly analyze the peptidome of neuroendocrine tissues of insects, particularly Drosophila melanogaster, by MALDI-TOF MS.
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Affiliation(s)
- Christian Wegener
- Emmy Noether Neuropeptide Group, Animal Physiology, Philipps-University, Marburg, Germany
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Herbert Z, Pollák E, Zougman A, Boros A, Kapan N, Molnár L. Identification of novel neuropeptides in the ventral nerve cord ganglia and their targets in an annelid worm, Eisenia fetida. J Comp Neurol 2009; 514:415-32. [PMID: 19350635 DOI: 10.1002/cne.22043] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Periviscerokinins (PVKs) and pyrokinins (PKs) are neuropeptides known in several arthropod species. Sequence homology of these peptides with the molluscan small cardioactive peptides reveals that the occurrence of PVKs and PKs is not restricted to arthropods. Our study focuses on the biochemical and immunocytochemical identification of neuropeptides with sequence homology to PVKs and PKs in the central and peripheral nervous system of the earthworm Eisenia fetida. By means of affinity chromatography, nanoflow liquid chromatography, and high accuracy mass spectrometry, six peptides, SPFPR(L/I)amide, APFPR(L/I)amide, SPLPR(L/I)amide, SFVR(L/I)amide, AFVR(L/I)amide, and SPAFVR(L/I)amide, were identified in the central nervous system with the common -XR(L/I)amide C-terminal sequence. The exact anatomical position of 13 labeled XR(I/L)amide expressing neuron groups and numerous peptide-containing fibers were determined by means of immunocytochemistry and confocal laser scanning microscopy in whole-mount preparations of ventral nerve cord ganglia. The majority of the stained neurons were interneurons with processes joining the distinct fine-fibered polysegmental tracts in the central neuropil. Some stained fibers were seen running in each segmental nerve that innervated metanephridia and body wall. Distinct groups of neurosecretory cells characterized by small round soma and short processes were also identified. Based on immunoelectron microscopy six different types of labeled cells were described showing morphological heterogeneity of earthworm peptides containing elements. Our findings confirm that the sequence of the identified earthworm neuropeptides homologous to the insect PVKs and PKs suggesting that these peptides are phylogenetically conservative molecules and are expressed in sister-groups of animals such as annelids, mollusks, and insects.
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Affiliation(s)
- Zsófia Herbert
- Division of Neurobiology Department of Biology II and Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universitat Munich, D-82152 Martinsried, Germany.
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24
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Wegener C, Gorbashov A. Molecular evolution of neuropeptides in the genus Drosophila. Genome Biol 2008; 9:R131. [PMID: 18717992 PMCID: PMC2575521 DOI: 10.1186/gb-2008-9-8-r131] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 07/24/2008] [Accepted: 08/21/2008] [Indexed: 11/10/2022] Open
Abstract
The first genomic and chemical characterization of fruit fly neuropeptides outside Drosophila melanogaster provides insights into the evolution of the neuropeptidome in this genus. Background Neuropeptides comprise the most diverse group of neuronal signaling molecules. They often occur as multiple sequence-related copies within single precursors (the prepropeptides). These multiple sequence-related copies have not arisen by gene duplication, and it is debated whether they are mutually redundant or serve specific functions. The fully sequenced genomes of 12 Drosophila species provide a unique opportunity to study the molecular evolution of neuropeptides. Results We data-mined the 12 Drosophila genomes for homologs of neuropeptide genes identified in Drosophila melanogaster. We then predicted peptide precursors and the neuropeptidome, and biochemically identified about half of the predicted peptides by direct mass spectrometric profiling of neuroendocrine tissue in four species covering main phylogenetic lines of Drosophila. We found that all species have an identical neuropeptidome and peptide hormone complement. Calculation of amino acid distances showed that ortholog peptide copies are highly sequence-conserved between species, whereas the observed sequence variability between peptide copies within single precursors must have occurred prior to the divergence of the Drosophila species. Conclusion We provide a first genomic and chemical characterization of fruit fly neuropeptides outside D. melanogaster. Our results suggest that neuropeptides including multiple peptide copies are under stabilizing selection, which suggests that multiple peptide copies are functionally important and not dispensable. The last common ancestor of Drosophila obviously had a set of neuropeptides and peptide hormones identical to that of modern fruit flies. This is remarkable, since drosophilid flies have adapted to very different environments.
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Affiliation(s)
- Christian Wegener
- Emmy Noether Neuropeptide Group, Animal Physiology, Department of Biology, Philipps-University, Karl-von-Frisch-Strasse, D-35032 Marburg, Germany.
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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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26
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Takeuchi H, Paul RK, Matsuzaka E, Kubo T. EcR-A expression in the brain and ovary of the honeybee (Apis mellifera L.). Zoolog Sci 2007; 24:596-603. [PMID: 17867861 DOI: 10.2108/zsj.24.596] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 01/19/2007] [Indexed: 11/17/2022]
Abstract
We previously demonstrated that six genes involved in ecdysteroid signaling are expressed preferentially in Kenyon-cell subtypes in the mushroom bodies of the honeybee (Apis mellifera L.). To further examine the possible involvement of ecdysteroid signaling in honeybee brain function, we isolated a cDNA for the A isoform of the ecdysone receptor gene homolog AmEcR-A and analyzed its expression in the brain. In situ hybridization revealed that AmEcR-A is expressed selectively in the small-type Kenyon cells of the mushroom bodies in the worker and queen brain, like AmE74 and AmHR38, suggesting a possible association of these gene products. Analysis of AmEcR-A expression in queen and worker abdomens demonstrated that AmEcR-A is strongly expressed in nurse cells of the queen ovary, suggesting that ecdysteroid and ecdysteroid signaling have roles in oogenesis. Our present results further support the possible involvement of ecdysteroid signaling in brain function, as well as in regulating queen reproductive physiology in the adult honeybee.
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Affiliation(s)
- Hideaki Takeuchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
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27
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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: 51] [Impact Index Per Article: 3.0] [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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28
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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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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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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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