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Abstract
We review the properties and uses of cell lines in Drosophila research, emphasizing the variety of lines, the large body of genomic and transcriptional data available for many of the lines, and the variety of ways the lines have been used to provide tools for and insights into the developmental, molecular, and cell biology of Drosophila and mammals.
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Affiliation(s)
- Lucy Cherbas
- Drosophila Genomics Resource Center, Indiana University, 1001 East Third Street, Bloomington, IN 47405, USA; Department of Biology, Indiana University, 1001 East Third Street, Bloomington, IN 47405, USA.
| | - Lei Gong
- Drosophila Genomics Resource Center, Indiana University, 1001 East Third Street, Bloomington, IN 47405, USA.
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2
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Cardoso JC, Félix RC, Fonseca VG, Power DM. Feeding and the rhodopsin family g-protein coupled receptors in nematodes and arthropods. Front Endocrinol (Lausanne) 2012; 3:157. [PMID: 23264768 PMCID: PMC3524798 DOI: 10.3389/fendo.2012.00157] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 11/22/2012] [Indexed: 12/13/2022] Open
Abstract
In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs) play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologs of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans), and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster), suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologs of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR) that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.
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Affiliation(s)
- João C.R. Cardoso
- Molecular Comparative Endocrinology, Centre of Marine Sciences, Universidade do AlgarveFaro, Portugal
- *Correspondence: João C.R. Cardoso, Molecular Comparative Endocrinology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, Faro 8005-139, Portugal. e-mail:
| | - Rute C. Félix
- Molecular Comparative Endocrinology, Centre of Marine Sciences, Universidade do AlgarveFaro, Portugal
| | - Vera G. Fonseca
- Molecular Comparative Endocrinology, Centre of Marine Sciences, Universidade do AlgarveFaro, Portugal
| | - Deborah M. Power
- Molecular Comparative Endocrinology, Centre of Marine Sciences, Universidade do AlgarveFaro, Portugal
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3
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Aerts S, Quan XJ, Claeys A, Naval Sanchez M, Tate P, Yan J, Hassan BA. Robust target gene discovery through transcriptome perturbations and genome-wide enhancer predictions in Drosophila uncovers a regulatory basis for sensory specification. PLoS Biol 2010; 8:e1000435. [PMID: 20668662 PMCID: PMC2910651 DOI: 10.1371/journal.pbio.1000435] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 06/14/2010] [Indexed: 01/08/2023] Open
Abstract
CisTarget X is a novel computational method that accurately predicts Atonal governed regulatory networks in the retina of the fruit fly. A comprehensive systems-level understanding of developmental programs requires the mapping of the underlying gene regulatory networks. While significant progress has been made in mapping a few such networks, almost all gene regulatory networks underlying cell-fate specification remain unknown and their discovery is significantly hampered by the paucity of generalized, in vivo validated tools of target gene and functional enhancer discovery. We combined genetic transcriptome perturbations and comprehensive computational analyses to identify a large cohort of target genes of the proneural and tumor suppressor factor Atonal, which specifies the switch from undifferentiated pluripotent cells to R8 photoreceptor neurons during larval development. Extensive in vivo validations of the predicted targets for the proneural factor Atonal demonstrate a 50% success rate of bona fide targets. Furthermore we show that these enhancers are functionally conserved by cloning orthologous enhancers from Drosophila ananassae and D. virilis in D. melanogaster. Finally, to investigate cis-regulatory cross-talk between Ato and other retinal differentiation transcription factors (TFs), we performed motif analyses and independent target predictions for Eyeless, Senseless, Suppressor of Hairless, Rough, and Glass. Our analyses show that cisTargetX identifies the correct motif from a set of coexpressed genes and accurately predicts target genes of individual TFs. The validated set of novel Ato targets exhibit functional enrichment of signaling molecules and a subset is predicted to be coregulated by other TFs within the retinal gene regulatory network. Tens of thousands of regulatory elements determine the spatiotemporal expression pattern of protein-coding genes in the metazoan genome. Each regulatory element, when bound by the appropriate transcription factors, can affect the temporal transcription of a nearby target gene in a particular cell type. Annotating the genome for regulatory elements, as well as determining the input transcription factors for each element, is a key challenge in genome biology. In this study, we introduce a computational method, cisTargetX, that predicts transcription factor binding motifs and their target genes through the integration of gene expression data and comparative genomics. We first validate this method in silico using public gene expression data and, then, apply cisTargetX to the developmental program governing photoreceptor neuron specification in the retina of Drosophila melanogaster. Particularly, we perturbed predicted key transcription factors during the initial steps of neurogenesis; measure gene expression by microarrays; identify motifs and predict target genes; validate the predictions in vivo using transgenic animals; and study several functional and evolutionary aspects of the validated regulatory elements for the proneural factor Atonal. Overall, we show that cisTargetX efficiently predicts genetic regulatory interactions and provides mechanistic insight into gene regulatory networks of postembryonic developmental systems.
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Affiliation(s)
- Stein Aerts
- Laboratory of Neurogenetics, Department of Molecular and Developmental Genetics, VIB, Leuven, Belgium
- Laboratory of Computational Biology, Katholieke Universiteit (K.U.) Leuven, Leuven, Belgium
- Center for Human Genetics, K.U. Leuven, Leuven, Belgium
- Doctoral Program in Molecular and Developmental Genetics, K.U. Leuven Group Biomedicine, Leuven, Belgium
- * E-mail: (SA); (BAH)
| | - Xiao-Jiang Quan
- Laboratory of Neurogenetics, Department of Molecular and Developmental Genetics, VIB, Leuven, Belgium
- Center for Human Genetics, K.U. Leuven, Leuven, Belgium
| | - Annelies Claeys
- Laboratory of Neurogenetics, Department of Molecular and Developmental Genetics, VIB, Leuven, Belgium
- Center for Human Genetics, K.U. Leuven, Leuven, Belgium
| | - Marina Naval Sanchez
- Laboratory of Computational Biology, Katholieke Universiteit (K.U.) Leuven, Leuven, Belgium
- Doctoral Program in Molecular and Developmental Genetics, K.U. Leuven Group Biomedicine, Leuven, Belgium
| | - Phillip Tate
- Laboratory of Neurogenetics, Department of Molecular and Developmental Genetics, VIB, Leuven, Belgium
- Center for Human Genetics, K.U. Leuven, Leuven, Belgium
| | - Jiekun Yan
- Laboratory of Neurogenetics, Department of Molecular and Developmental Genetics, VIB, Leuven, Belgium
- Center for Human Genetics, K.U. Leuven, Leuven, Belgium
| | - Bassem A. Hassan
- Laboratory of Neurogenetics, Department of Molecular and Developmental Genetics, VIB, Leuven, Belgium
- Center for Human Genetics, K.U. Leuven, Leuven, Belgium
- Doctoral Program in Molecular and Developmental Genetics, K.U. Leuven Group Biomedicine, Leuven, Belgium
- * E-mail: (SA); (BAH)
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4
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Powell LM, Deaton AM, Wear MA, Jarman AP. Specificity of Atonal and Scute bHLH factors: analysis of cognate E box binding sites and the influence of Senseless. Genes Cells 2008; 13:915-29. [PMID: 18681894 PMCID: PMC3287287 DOI: 10.1111/j.1365-2443.2008.01217.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The question of how proneural bHLH transcription factors recognize and regulate their target genes is still relatively poorly understood. We previously showed that Scute (Sc) and Atonal (Ato) target genes have different cognate E box motifs, suggesting that specific DNA interactions contribute to differences in their target gene specificity. Here we show that Sc and Ato proteins (in combination with Daughterless) can activate reporter gene expression via their cognate E boxes in a non-neuronal cell culture system, suggesting that the proteins have strong intrinsic abilities to recognize different E box motifs in the absence of specialized cofactors. Functional comparison of E boxes from several target genes and site-directed mutagenesis of E box motifs suggests that specificity and activity require further sequence elements flanking both sides of the previously identified E box motifs. Moreover, the proneural cofactor, Senseless, can augment the function of Sc and Ato on their cognate E boxes and therefore may contribute to proneural specificity.
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Affiliation(s)
- Lynn M. Powell
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Martin A. Wear
- Centre for Translational and Chemical Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew P. Jarman
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
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5
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Birse RT, Johnson EC, Taghert PH, Nässel DR. Widely distributed Drosophila G-protein-coupled receptor (CG7887) is activated by endogenous tachykinin-related peptides. ACTA ACUST UNITED AC 2006; 66:33-46. [PMID: 16193493 DOI: 10.1002/neu.20189] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neuropeptides related to vertebrate tachykinins have been identified in Drosophila. Two Drosophila G-protein-coupled receptors (GPCRs), designated NKD (CG6515) and DTKR (CG7887), cloned earlier, display sequence similarities to mammalian tachykinin receptors. However, they were not characterized with the endogenous Drosophila tachykinins (DTKs). The present study characterizes one of these receptors, DTKR. We determined that HEK-293 cells transfected with DTKR displayed dose-dependent increases in both intracellular calcium and cyclic AMP levels in response to the different DTK peptides. DTK peptides also induced internalization of DTKR-green fluorescent protein (GFP) fusion constructs in HEK-293 cells. We generated specific antireceptor antisera and showed that DTKR is widely distributed in the adult brain and more scarcely in the larval CNS. The distribution of the receptor in brain neuropils corresponds well with the distribution of its ligands, the DTKs. Our findings suggest that DTKR is a DTK receptor in Drosophila and that this ligand-receptor system plays multiple functional roles.
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Affiliation(s)
- Ryan T Birse
- Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden
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6
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Winther AME, Acebes A, Ferrús A. Tachykinin-related peptides modulate odor perception and locomotor activity in Drosophila. Mol Cell Neurosci 2006; 31:399-406. [PMID: 16289899 DOI: 10.1016/j.mcn.2005.10.010] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 10/09/2005] [Accepted: 10/14/2005] [Indexed: 11/16/2022] Open
Abstract
The invertebrate tachykinin-related peptides (TKRPs) constitute a conserved family, structurally related to the mammalian tachykinins, including members such as substance P and neurokinins A and B. Although their expression has been documented in the brains of insects and mammals, their neural functions remain largely unknown, particularly in behavior. Here, we have studied the role of TKRPs in Drosophila. We have analyzed the olfactory perception and the locomotor activity of individuals in which TKRPs are eliminated in the nervous system specifically, by using RNAi constructs to silence gene expression. The perception of specific odorants and concentrations is modified towards a loss of sensitivity, thus resulting in a significant change of the behavioral response towards indifference. In locomotion assays, the TKRP-deficient flies show hyperactivity. We conclude that these peptides are modulators of olfactory perception and locomotion activity in agreement with their abundant expression in the olfactory lobes and central complex. In these brain centers, TKRPs seem to enhance the regulatory inhibition of the neurons in which they are expressed.
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Affiliation(s)
- Asa M E Winther
- Department of Zoology, Stockholm University, S-106 91 Stockholm, Sweden
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7
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Powell LM, Zur Lage PI, Prentice DRA, Senthinathan B, Jarman AP. The proneural proteins Atonal and Scute regulate neural target genes through different E-box binding sites. Mol Cell Biol 2004; 24:9517-26. [PMID: 15485919 PMCID: PMC522279 DOI: 10.1128/mcb.24.21.9517-9526.2004] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For a particular functional family of basic helix-loop-helix (bHLH) transcription factors, there is ample evidence that different factors regulate different target genes but little idea of how these different target genes are distinguished. We investigated the contribution of DNA binding site differences to the specificities of two functionally related proneural bHLH transcription factors required for the genesis of Drosophila sense organ precursors (Atonal and Scute). We show that the proneural target gene, Bearded, is regulated by both Scute and Atonal via distinct E-box consensus binding sites. By comparing with other Ato-dependent enhancer sequences, we define an Ato-specific binding consensus that differs from the previously defined Scute-specific E-box consensus, thereby defining distinct E(Ato) and E(Sc) sites. These E-box variants are crucial for function. First, tandem repeats of 20-bp sequences containing E(Ato) and E(Sc) sites are sufficient to confer Atonal- and Scute-specific expression patterns, respectively, on a reporter gene in vivo. Second, interchanging E(Ato) and E(Sc) sites within enhancers almost abolishes enhancer activity. While the latter finding shows that enhancer context is also important in defining how proneural proteins interact with these sites, it is clear that differential utilization of DNA binding sites underlies proneural protein specificity.
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Affiliation(s)
- Lynn M Powell
- Division of Biomedical Sciences, University of Edinburgh, George Square, Edinburgh EH8 9XD, United Kingdom
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8
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Mattar P, Britz O, Johannes C, Nieto M, Ma L, Rebeyka A, Klenin N, Polleux F, Guillemot F, Schuurmans C. A screen for downstream effectors of Neurogenin2 in the embryonic neocortex. Dev Biol 2004; 273:373-89. [PMID: 15328020 DOI: 10.1016/j.ydbio.2004.06.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Revised: 06/18/2004] [Accepted: 06/22/2004] [Indexed: 11/29/2022]
Abstract
Neurogenin (Ngn) 1 and Ngn2 encode basic-helix-loop-helix transcription factors expressed in the developing neocortex. Like other proneural genes, Ngns participate in the specification of neural fates and neuronal identities, but downstream effectors remain poorly defined. We set out to identify Ngn2 effectors in the cortex using a subtractive hybridization screen and identified several regionally expressed genes that were misregulated in Ngn2 and Ngn1;Ngn2 mutants. Included were genes down-regulated in germinal zone progenitors (e.g., Nlgn1, Unc5H4, and Dcc) and in postmitotic neurons in the cortical plate (e.g., Bhlhb5 and NFIB) and subplate (e.g., Mef2c, srGAP3, and protocadherin 9). Further analysis revealed that Ngn2 mutant subplate neurons were misspecified and that thalamocortical afferents (TCAs) that normally target this layer instead inappropriately projected towards the germinal zone. Strikingly, EphA5 and Sema3c, which encode repulsive guidance cues, were down-regulated in the Ngn2 and Ngn1;Ngn2 mutant germinal zones, providing a possible molecular basis for axonal targeting defects. Thus, we identified several new components of the differentiation cascade(s) activated downstream of Ngn1 and Ngn2 and provided novel insights into a new developmental process controlled by these proneural genes. Further analysis of the genes isolated in our screen should provide a fertile basis for understanding the molecular mechanisms underlying corticogenesis.
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Affiliation(s)
- Pierre Mattar
- University of Calgary, Calgary, Alberta, Canada T2N 4N1
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9
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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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10
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Meeusen T, Mertens I, De Loof A, Schoofs L. G Protein-Coupled Receptors in Invertebrates: A State of the Art. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 230:189-261. [PMID: 14692683 DOI: 10.1016/s0074-7696(03)30004-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
G protein-coupled receptors (GPCRs) constitute one of the largest and most ancient superfamilies of membrane-spanning proteins. We focus on neuropeptide GPCRs, in particular on those of invertebrates. In general, such receptors mediate the responses of signaling molecules that constitute the highest hierarchical position in the regulation of physiological processes. Until recently, only a few of these receptors were identified in invertebrates. However, the availability of a plethora of genomic information has boosted the discovery of novel members in several invertebrate species, such as Drosophila, in which 18 neuropeptide GPCRs have been characterized. The finalization of genomic projects in other invertebrates will lead to a similar expansion of GPCR understanding. Many new insights regarding neuropeptide regulation have followed from the discovery of their cognate receptors. Furthermore, information on GPCR signaling is still fragmentary and the elucidation of these pathways in model insects such as Drosophila will lead to further insights in other species, including mammals. In this review we present the current status of what is known about invertebrate GPCRs, discuss some novel perceptions that follow from the identified members, and, finally, present some future prospects.
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Affiliation(s)
- Tom Meeusen
- Laboratory of Developmental Physiology, Genomics, and Proteomics, K.U. Leuven, B-3000 Leuven, Belgium
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11
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Radford JC, Davies SA, Dow JAT. Systematic G-protein-coupled receptor analysis in Drosophila melanogaster identifies a leucokinin receptor with novel roles. J Biol Chem 2002; 277:38810-7. [PMID: 12163486 DOI: 10.1074/jbc.m203694200] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leucokinins are insect neuropeptides that stimulate hindgut motility and renal fluid secretion. Drosophila has a single leucokinin gene, pp, encoding the longest known leucokinin, Drosokinin. To identify its receptor, a genome-wide scan for G-protein-coupled receptors was performed in silico and candidate receptors identified by similarity to known tachykinin receptors. The deduced peptides were expressed, with a transgene for the calcium reporter aequorin, in S2 cells and only one gene (CG10626) encoded a protein that responded to Drosokinin. The properties of the heterologously expressed receptor (action through intracellular calcium with an EC(50) of 4 x 10(-11) m and a t(1/2) <1 s) match closely those reported for the action of Drosokinin on Malpighian (renal) tubules. Antibodies raised against the receptor identified known sites of leucokinin action: stellate cells of the Malpighian tubule, two triplets of cells in the pars intercerebralis of the adult central nervous system, and additional cells in larval central nervous system. Western blots and reverse transcription-PCR confirmed these locations, but also identified expression in male and female gonads. These tissues also displayed elevated calcium in response to Drosokinin, demonstrating novel roles for leucokinin. A functional genomic approach has thus yielded the first complete characterization of a leucokinin receptor in an insect.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Calcium/metabolism
- Drosophila Proteins/classification
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Drosophila melanogaster/genetics
- Drosophila melanogaster/metabolism
- Embryo, Nonmammalian/anatomy & histology
- Embryo, Nonmammalian/physiology
- Female
- GTP-Binding Proteins/classification
- GTP-Binding Proteins/genetics
- GTP-Binding Proteins/metabolism
- Genes, Insect
- Genes, Reporter
- Humans
- Male
- Malpighian Tubules/cytology
- Malpighian Tubules/metabolism
- Molecular Sequence Data
- Nervous System/cytology
- Nervous System/metabolism
- Neuropeptides/metabolism
- Receptors, Cell Surface/classification
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Neuropeptide/classification
- Receptors, Neuropeptide/genetics
- Receptors, Neuropeptide/metabolism
- Sequence Alignment
- Transgenes
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Affiliation(s)
- Jonathan C Radford
- Division of Molecular Genetics, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G11 6NU, United Kingdom
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12
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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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13
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Bushdid PB, Chen CL, Brantley DM, Yull F, Raghow R, Kerr LD, Barnett JV. NF-kappaB mediates FGF signal regulation of msx-1 expression. Dev Biol 2001; 237:107-15. [PMID: 11518509 DOI: 10.1006/dbio.2001.0356] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The nuclear factor-kappaB (NF-kappaB) family of transcription factors is involved in proliferation, differentiation, and apoptosis in a stage- and cell-dependent manner. Recent evidence has shown that NF-kappaB activity is necessary for both chicken and mouse limb development. We report here that the NF-kappaB family member c-rel and the homeodomain gene msx-1 have partially overlapping expression patterns in the developing chick limb. In addition, inhibition of NF-kappaB activity resulted in a decrease in msx-1 mRNA expression. Sequence analysis of the msx-1 promoter revealed three potential kappaB-binding sites similar to the interferon-gamma (IFN-gamma) kappaB-binding site. These sites bound to c-Rel, as shown by electrophoretic mobility shift assay (EMSA). Furthermore, inhibition of NF-kappaB activity significantly reduced transactivation of the msx-1 promoter in response to FGF-2/-4, known stimulators of msx-1 expression. These results suggest that NF-kappaB mediates the FGF-2/-4 signal regulation of msx-1 gene expression.
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Affiliation(s)
- P B Bushdid
- Department of Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee 37232, USA.
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14
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Hewes RS, Taghert PH. Neuropeptides and neuropeptide receptors in the Drosophila melanogaster genome. Genome Res 2001; 11:1126-42. [PMID: 11381038 PMCID: PMC311076 DOI: 10.1101/gr.169901] [Citation(s) in RCA: 403] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recent genetic analyses in worms, flies, and mammals illustrate the importance of bioactive peptides in controlling numerous complex behaviors, such as feeding and circadian locomotion. To pursue a comprehensive genetic analysis of bioactive peptide signaling, we have scanned the recently completed Drosophila genome sequence for G protein-coupled receptors sensitive to bioactive peptides (peptide GPCRs). Here we describe 44 genes that represent the vast majority, and perhaps all, of the peptide GPCRs encoded in the fly genome. We also scanned for genes encoding potential ligands and describe 22 bioactive peptide precursors. At least 32 Drosophila peptide receptors appear to have evolved from common ancestors of 15 monophyletic vertebrate GPCR subgroups (e.g., the ancestral gastrin/cholecystokinin receptor). Six pairs of receptors are paralogs, representing recent gene duplications. Together, these findings shed light on the evolutionary history of peptide GPCRs, and they provide a template for physiological and genetic analyses of peptide signaling in Drosophila.
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Affiliation(s)
- R S Hewes
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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15
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Holmes SP, He H, Chen AC, lvie GW, Pietrantonio PV. Cloning and transcriptional expression of a leucokinin-like peptide receptor from the southern cattle tick, Boophilus microplus (Acari: Ixodidae). INSECT MOLECULAR BIOLOGY 2000; 9:457-465. [PMID: 11029664 DOI: 10.1046/j.1365-2583.2000.00208.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Leucokinins are invertebrate neuropeptides that exhibit myotropic and diuretic activity. Only one leucokinin-like peptide receptor is known, the lymnokinin receptor from the mollusc Lymnaea stagnalis. A cDNA encoding a leucokinin-like peptide receptor was cloned from the Southern cattle tick, Boophilus microplus, a pest of cattle world-wide. This is the first neuropeptide receptor known from the Acari and the second known in the subfamily of leucokinin-like peptide G-protein-coupled receptors. The deduced amino acid sequence exhibits 40% identity to the lymnokinin receptor. The receptor transcript is present in all tick life stages as determined by semiquantitative reverse transcription polymerase chain reaction. We also propose that the sequence AAF50775.1 from the Drosophila melanogaster genome (CG10626) encodes the first identified insect leucokinin receptor.
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Affiliation(s)
- S P Holmes
- Department of Entomology, Texas A & M University, College Station, Texas, 77843-2475, USA
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16
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Siviter RJ, Coast GM, Winther AM, Nachman RJ, Taylor CA, Shirras AD, Coates D, Isaac RE, Nässel DR. Expression and functional characterization of a Drosophila neuropeptide precursor with homology to mammalian preprotachykinin A. J Biol Chem 2000; 275:23273-80. [PMID: 10801863 DOI: 10.1074/jbc.m002875200] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peptides structurally related to mammalian tachykinins have recently been isolated from the brain and intestine of several insect species, where they are believed to function as both neuromodulators and hormones. Further evidence for the signaling role of insect tachykinin-related peptides was provided by the cloning and characterization of cDNAs for two tachykinin receptors from Drosophila melanogaster. However, no endogenous ligand has been isolated for the Drosophila tachykinin receptors to date. Analysis of the Drosophila genome allowed us to identify a putative tachykinin-related peptide prohormone (prepro-DTK) gene. A 1.5-kilobase pair cDNA amplified from a Drosophila head cDNA library contained an 870-base pair open reading frame, which encodes five novel Drosophila tachykinin-related peptides (called DTK peptides) with conserved C-terminal FXGXR-amide motifs common to other insect tachykinin-related peptides. The tachykinin-related peptide prohormone gene (Dtk) is both expressed and post-translationally processed in larval and adult midgut endocrine cells and in the central nervous system, with midgut expression starting at stage 17 of embryogenesis. The predicted Drosophila tachykinin peptides have potent stimulatory effects on the contractions of insect gut. These data provide additional evidence for the conservation of both the structure and function of the tachykinin peptides in the brain and gut during the course of evolution.
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Affiliation(s)
- R J Siviter
- School of Biology, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
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17
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Colas JF, Launay JM, Vonesch JL, Hickel P, Maroteaux L. Serotonin synchronises convergent extension of ectoderm with morphogenetic gastrulation movements in Drosophila. Mech Dev 1999; 87:77-91. [PMID: 10495273 DOI: 10.1016/s0925-4773(99)00141-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During Drosophila gastrulation, convergent extension of the ectoderm is required for germband extension. Adhesive heterogeneity within ectodermal cells has been proposed to trigger the intercalation of cells responsible for this movement. Segmentation genes would impose this heterogeneity by establishing a pair-rule pattern of cell adhesion properties. We previously reported that the serotonin receptor (5-ht(2Dro)) is expressed in the presumptive ectoderm with a pair-rule pattern. Here, we show that the peaks of 5-ht(2Dro) expression and serotonin synthesis coincide precisely with the onset of convergent extension of the ectoderm. Gastrulae genetically depleted of serotonin or the 5-ht(2Dro) receptor do not extend their germband properly, and the ectodermal movements becomes asynchronous with the morphogenetic movements in the endoderm and mesoderm. Associated with the beginning of this desynchronisation, is an altered subcellular localisation of adherens junctions within the ectoderm. Combined, these data highlight the role of the ectoderm in Drosophila gastrulation and support the notion that serotonin signalling through the 5-HT(2Dro) receptor triggers changes in cell adhesiveness that are necessary for cell intercalation.
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Affiliation(s)
- J F Colas
- IGBMC-CNRS-INSERM, Université de Strasbourg, BP 163, Illkirch, France
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18
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Persson MG, Nässel DR. Neuropeptides in insect sensory neurones: tachykinin-, FMRFamide- and allatotropin-related peptides in terminals of locust thoracic sensory afferents. Brain Res 1999; 816:131-41. [PMID: 9878709 DOI: 10.1016/s0006-8993(98)01139-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Sensory afferents in the thoracic ganglia of the locust Locusta migratoria were labelled with antisera to different neuropeptides: locustatachykinins, FMRFamide and allatotropin. The locustatachykinin-immunoreactive (LTKIR) sensory fibres were derived from the legs and entered the ventral sensory neuropil of each of the thoracic ganglia via nerve 5. In the thoracic neuropil, the LTKIR sensory fibres formed a distinct plexus of terminations ventrally in the ipsilateral hemisphere. The peripheral cell bodies of the sensory neurones could not be revealed, but lesion experiments indicated that origin of the LTKIR fibres was the tarsus of each leg. Possibly the thin fibres are from tarsal chemoreceptors. Double labelling immunocytochemistry revealed that all the LTKIR sensory fibres contained colocalized FMRFamide immunoreactivity. A larger population of sensory fibres reacted with antiserum to moth (Manduca sexta) allatotropin. By means of double labelling immunocytochemistry, we could show that the LTKIR fibres constituted a subpopulation of the larger set of allatotropin-like immunoreactive fibres. Thus some sensory fibres may contain colocalized peptides related to locustatachykinins, FMRFamide-related peptide(s) and allatotropin-like peptide. A separate non-overlapping small set of sensory fibres in nerve 5 reacted with an antiserum to serotonin. Sensory fibres of the other nerves of the ventral nerve cord, including the abdominal ganglia, did not react with the peptide antisera. Since acetylcholine is the likely primary neurotransmitter of insect sensory fibres, it is possible that the peptides and serotonin are colocalized with this transmitter and serve modulatory functions in a subset of the leg afferents.
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Affiliation(s)
- M G Persson
- Department of Zoology, Stockholm University, S-10691, Stockholm, Sweden
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19
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Abstract
Peptides with sequence similarities to members of the tachykinin family have been identified in a number of invertebrates belonging to the mollusca, echiuridea, insecta and crustacea. These peptides have been designated tachykinin-related peptides (TRPs) and are characterized by the preserved C-terminal pentapeptide FX1GX2Ramide (X1 and X2 are variable residues). All invertebrate TRPs are myostimulatory on insect hindgut muscle, but also have a variety of additional actions: they can induce contractions in cockroach foregut and oviduct and in moth heart muscle, trigger a motor rhythm in the crab stomatogastric ganglion, depolarize or hyperpolarize identified interneurons of locust and the snail Helix and induce release of adipokinetic hormone from the locust corpora cardiaca. Two putative TRP receptors have been cloned from Drosophila; both are G-protein coupled and expressed in the nervous system. The invertebrate TRPs are distributed in interneurons of the CNS of Limulus, crustaceans and insects. In the latter two groups TRPs are also present in the stomatogastric nervous system and in insects endocrine cells of the midgut display TRP-immunoreactivity. In arthropods the distribution of TRPs in neuronal processes of the brain displays similar patterns. Also in coelenterates, flatworms and molluscs TRPs have been demonstrated in neurons. The activity of different TRPs has been explored in several assays and it appears that an amidated C-terminal hexapeptide (or longer) is required for bioactivity. In many invertebrate assays the first generation substance P antagonist spantide I is a potent antagonist of invertebrate TRPs and substance P. Locustatachykinins stimulate adenylate cyclase in locust interneurons and glandular cells of the corpora cardiaca, but in other tissues the putative second messenger systems have not yet been identified. The heterologously expressed Drosophila TRP receptors coupled to the phospholipase C pathway and could induce elevations of inositol triphosphate. The structures, distributions and actions of TRPs in various invertebrates are compared and it is concluded that the TRPs are multifunctional peptides with targets both in the central and peripheral nervous system and other tissues, similar to vertebrate tachykinins. Invertebrate TRPs may also be involved in developmental processes.
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Affiliation(s)
- D R Nässel
- Department of Zoology, Stockholm University, Sweden.
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Sun Y, Jan LY, Jan YN. Transcriptional regulation of atonal during development of the Drosophila peripheral nervous system. Development 1998; 125:3731-40. [PMID: 9716538 DOI: 10.1242/dev.125.18.3731] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
atonal is a proneural gene for the development of Drosophila chordotonal organs and photoreceptor cells. We show here that atonal expression is controlled by modular enhancer elements located 5′ or 3′ to the atonal-coding sequences. During chordotonal organ development, the 3′ enhancer directs expression in proneural clusters; whereas successive modular enhancers located in the 5′ region drive tissue-specific expression in chordotonal organ precursors in the embryo and larval leg, wing and antennal imaginal discs. Similarly, in the eye disc, the 3′ enhancer directs initial expression in a stripe anterior to the morphogenetic furrow. These atonal-expressing cells are then patterned through a Notch-dependent process into initial clusters, representing the earliest patterning event yet identified during eye morphogenesis. A distinct 5′ enhancer drives expression in intermediate groups and R8 cells within and posterior to the morphogenetic furrow. Both enhancers are required for normal atonal function in the eye. The 5′ enhancer, but not the 3′ enhancer, depends on endogenous atonal function, suggesting a switch from regulation directed by other upstream genes to atonal autoregulation during the process of lateral inhibition. The regulatory regions identified in this study can thus account for atonal expression in every tissue and essentially in every stage of its expression during chordotonal organ and photoreceptor development.
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Affiliation(s)
- Y Sun
- Departments of Physiology and Biochemistry, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143-0725, USA
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Lage P, Jan YN, Jarman AP. Requirement for EGF receptor signalling in neural recruitment during formation of Drosophila chordotonal sense organ clusters. Curr Biol 1997; 7:166-75. [PMID: 9395407 DOI: 10.1016/s0960-9822(97)70087-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Drosophila proneural genes act in the process of selecting neural precursors from undifferentiated ectoderm. The proneural gene atonal is required for the development of precursors of both chordotonal organs (stretch receptors) and photoreceptors. Although these types of sensory element are dissimilar in structure and function, they both occur as organized arrays of neurons. Previous studies have shown that clustering of photoreceptors involves local recruitment, and that signalling by the Drosophila epidermal growth factor receptor (DER) pathway is involved in the recruitment process. We present evidence that a similar mechanism is required for the clustering of embryonic chordotonal organs. RESULTS We have examined the expression patterns of atonal and genes of the DER pathway in wild-type and mutant backgrounds. Expression of atonal was restricted to a subset of the atonal-requiring chordotonal precursors, which we call founder precursors. The remaining precursors required DER signalling for their selection. Signalling by the founder precursors was initiated by atonal activating, directly or indirectly, rhomboid expression in these cells. Signalling by these founder precursors then provoked a response in the surrounding ectodermal cells, as shown by the activation of expression of the DER target genes pointed and argos. The signal and response then led to recruitment of some of the ectodermal cells to the chordotonal precursor cell fate. DER hyperactivation by misexpression of rhomboid resulted in excessive chordotonal precursor recruitment. CONCLUSIONS Increased numbers of chordotonal precursors are recruited by homeogenetic induction involving signalling via DER from founder precursors to surrounding ectodermal cells. We suggest that the reason chordotonal organs and photoreceptors share a requirement for the proneural gene atonal is that this gene activates a common pathway leading to neural aggregation.
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Affiliation(s)
- P Lage
- Institute of Cell and Molecular Biology, University of Edinburgh, King's Buildings, Edinburgh EH9 3JR, UK
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