1
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Goodchild J, Chen YJ, Blythe J, Firth LC, Hirst E, Bess K, Bristow J, Willis J, Baines R, Cash F, Muehlebach M, Buchholz A, Rendler S, Earley F, Crossthwaite A. A novel class of insecticidal alkylsulfones are potent inhibitors of vesicular acetylcholine transport. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 201:105854. [PMID: 38685234 DOI: 10.1016/j.pestbp.2024.105854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/01/2024] [Accepted: 03/06/2024] [Indexed: 05/02/2024]
Abstract
Pyridine alkylsulfone derivatives typified by oxazosulfyl (Sumitomo Chemical Company Ltd.) and compound A2 (Syngenta) represent a new class of insecticides, with potent activity against several insect orders. Whilst the MOA of this class has been attributed to interaction with the voltage-gated sodium channel (VGSC), here we present strong evidence that their toxicity to insects is mediated primarily through inhibition of the vesicular acetylcholine transporter (VAChT). Alkylsulfone intoxication in insects is characterised by (i) a reduction in cholinergic synaptic transmission efficiency demonstrated by a depression of cercal afferent activity in giant-interneurone preparations of American cockroach (Periplaneta americana), (ii) selective block of cholinergic-transmission dependent post-synaptic potentials in the Drosophila giant-fibre pathway and (iii) abolition of miniature excitatory post-synaptic currents (mEPSCs) in an identified synapse in Drosophila larvae. Ligand-binding studies using a tritiated example compound ([3H]-A1) revealed a single saturable binding-site, with low nanomolar Kd value, in membrane fractions of green bottle fly (Lucilia sericata). Binding is inhibited by vesamicol and by several examples of a previously identified class of insecticidal compounds known to target VAChT, the spiroindolines. Displacement of this binding by analogues of the radioligand reveals a strong correlation with insecticidal potency. No specific binding was detected in untransformed PC12 cells but a PC12 line stably expressing Drosophila VAChT showed similar affinity for [3H]-A1 as that seen in fly head membrane preparations. Previously identified VAChT point mutations confer resistance to the spiroindoline class of insecticides in Drosophila by Gal-4/UAS directed expression in cholinergic neurones and by CRISPR gene-editing of VAChT, but none of these flies show detectable cross-resistance to this new chemical class. Oxazosulfyl was previously shown to stabilise voltage-gated sodium channels in their slow-inactivated conformation with an IC50 value of 12.3μM but inhibits binding of [3H]-A1 with approximately 5000 times greater potency. We believe this chemistry class represents a novel mode-of-action with high potential for invertebrate selectivity.
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Affiliation(s)
- James Goodchild
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Ying-Ju Chen
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Judith Blythe
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Lucy C Firth
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Elizabeth Hirst
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Kirsty Bess
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Julia Bristow
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Jenny Willis
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Richard Baines
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK
| | - Francesca Cash
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK
| | - Michel Muehlebach
- Syngenta Crop Protection AG, Crop Protection Research, Schaffhauserstrasse 101, CH-4332 Stein, Switzerland
| | - Anke Buchholz
- Syngenta Crop Protection AG, Crop Protection Research, Schaffhauserstrasse 101, CH-4332 Stein, Switzerland
| | - Sebastian Rendler
- Syngenta Crop Protection AG, Crop Protection Research, Schaffhauserstrasse 101, CH-4332 Stein, Switzerland
| | - Fergus Earley
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Andrew Crossthwaite
- Syngenta, Bioscience, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
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2
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Corrales M, Cocanougher BT, Kohn AB, Wittenbach JD, Long XS, Lemire A, Cardona A, Singer RH, Moroz LL, Zlatic M. A single-cell transcriptomic atlas of complete insect nervous systems across multiple life stages. Neural Dev 2022; 17:8. [PMID: 36002881 PMCID: PMC9404646 DOI: 10.1186/s13064-022-00164-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/10/2022] [Indexed: 12/15/2022] Open
Abstract
Molecular profiles of neurons influence neural development and function but bridging the gap between genes, circuits, and behavior has been very difficult. Here we used single cell RNAseq to generate a complete gene expression atlas of the Drosophila larval central nervous system composed of 131,077 single cells across three developmental stages (1 h, 24 h and 48 h after hatching). We identify 67 distinct cell clusters based on the patterns of gene expression. These include 31 functional mature larval neuron clusters, 1 ring gland cluster, 8 glial clusters, 6 neural precursor clusters, and 13 developing immature adult neuron clusters. Some clusters are present across all stages of larval development, while others are stage specific (such as developing adult neurons). We identify genes that are differentially expressed in each cluster, as well as genes that are differentially expressed at distinct stages of larval life. These differentially expressed genes provide promising candidates for regulating the function of specific neuronal and glial types in the larval nervous system, or the specification and differentiation of adult neurons. The cell transcriptome Atlas of the Drosophila larval nervous system is a valuable resource for developmental biology and systems neuroscience and provides a basis for elucidating how genes regulate neural development and function.
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Affiliation(s)
- Marc Corrales
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Physiology, Development, and Neuroscience, Cambridge University, Cambridge, UK
| | - Benjamin T Cocanougher
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Zoology, Cambridge University, Cambridge, UK
| | - Andrea B Kohn
- Department of Neuroscience and Whitney Laboratory for Marine Biosciences, University of Florida, Gainesville/St. Augustine, FL, 32080, USA
| | - Jason D Wittenbach
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Xi S Long
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Andrew Lemire
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Albert Cardona
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Physiology, Development, and Neuroscience, Cambridge University, Cambridge, UK.,MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK
| | - Robert H Singer
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Leonid L Moroz
- Department of Neuroscience and Whitney Laboratory for Marine Biosciences, University of Florida, Gainesville/St. Augustine, FL, 32080, USA.
| | - Marta Zlatic
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA. .,Department of Zoology, Cambridge University, Cambridge, UK. .,MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK.
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3
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Opponent vesicular transporters regulate the strength of glutamatergic neurotransmission in a C. elegans sensory circuit. Nat Commun 2021; 12:6334. [PMID: 34732711 PMCID: PMC8566550 DOI: 10.1038/s41467-021-26575-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 09/22/2021] [Indexed: 11/30/2022] Open
Abstract
At chemical synapses, neurotransmitters are packaged into synaptic vesicles that release their contents in response to depolarization. Despite its central role in synaptic function, regulation of the machinery that loads vesicles with neurotransmitters remains poorly understood. We find that synaptic glutamate signaling in a C. elegans chemosensory circuit is regulated by antagonistic interactions between the canonical vesicular glutamate transporter EAT-4/VGLUT and another vesicular transporter, VST-1. Loss of VST-1 strongly potentiates glutamate release from chemosensory BAG neurons and disrupts chemotaxis behavior. Analysis of the circuitry downstream of BAG neurons shows that excess glutamate release disrupts behavior by inappropriately recruiting RIA interneurons to the BAG-associated chemotaxis circuit. Our data indicate that in vivo the strength of glutamatergic synapses is controlled by regulation of neurotransmitter packaging into synaptic vesicles via functional coupling of VGLUT and VST-1. The authors describe a vesicular transporter, VST-1, that is required in glutamatergic chemosensory neurons for chemotactic avoidance behavior in C. elegans. VST-1 antagonizes VGLUT-dependent packaging of glutamate into synaptic vesicles and determines the strength of synaptic glutamate signaling.
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4
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Vesicular neurotransmitter transporters in Drosophila melanogaster. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183308. [PMID: 32305263 DOI: 10.1016/j.bbamem.2020.183308] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 12/11/2022]
Abstract
Drosophila melanogaster express vesicular transporters for the storage of neurotransmitters acetylcholine, biogenic amines, GABA, and glutamate. The large array of powerful molecular-genetic tools available in Drosophila enhances the use of this model organism for studying transporter function and regulation.
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5
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Moriyama Y, Hatano R, Moriyama S, Uehara S. Vesicular polyamine transporter as a novel player in amine-mediated chemical transmission. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183208. [PMID: 32004521 DOI: 10.1016/j.bbamem.2020.183208] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/23/2020] [Accepted: 01/26/2020] [Indexed: 02/06/2023]
Abstract
The solute carrier 18B1 (SLC18B1) is the most recently identified gene of the vesicular amine transporter family and is conserved in the animal kingdom from insects to humans. Proteoliposomes containing the purified human SLC18B1 protein transport not only monoamines, but also polyamines, such as spermidine (Spd) and spermine (Spm), using an electrochemical gradient of H+ established by vacuolar H+-ATPase (V-ATPase) as the driving force. SLC18B1 gene knockdown abolished the exocytosis of polyamines from mast cells, which affected the secretion of histamine. SLC18B1 gene knockout decreased polyamine levels by ~20% in the brain, and impaired short- and long-term memory. Thus, the SLC18B1 protein is responsible for the vesicular storage and release of polyamines, and functions as a vesicular polyamine transporter (VPAT). VPAT may define when, where, and how polyamine-mediated chemical transmission occurs, providing insights into the more versatile and complex features of amine-mediated chemical transmission than currently considered.
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Affiliation(s)
- Yoshinori Moriyama
- Department of Biochemistry, Matsumoto Dental University, Shiojiri 399-0781, Japan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan; CYRIC Tohoku University, Sendai 980-8578, Japan.
| | - Ryo Hatano
- Department of Medicinal Physiology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Satomi Moriyama
- Laboratory of Bio-Molecular Dynamics, Department of Collaborative Research, Nara Medical University, Kashihara 634-8521, Japan
| | - Shunsuke Uehara
- Department of Biochemistry, Matsumoto Dental University, Shiojiri 399-0781, Japan
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6
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Vásquez-Procopio J, Osorio B, Cortés-Martínez L, Hernández-Hernández F, Medina-Contreras O, Ríos-Castro E, Comjean A, Li F, Hu Y, Mohr S, Perrimon N, Missirlis F. Intestinal response to dietary manganese depletion inDrosophila. Metallomics 2020; 12:218-240. [DOI: 10.1039/c9mt00218a] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Metabolic adaptations to manganese deficiency.
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7
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Brunet Avalos C, Maier GL, Bruggmann R, Sprecher SG. Single cell transcriptome atlas of the Drosophila larval brain. eLife 2019; 8:e50354. [PMID: 31746739 PMCID: PMC6894929 DOI: 10.7554/elife.50354] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 11/19/2019] [Indexed: 12/15/2022] Open
Abstract
Cell diversity of the brain and how it is affected by starvation, remains largely unknown. Here, we introduce a single cell transcriptome atlas of the entire Drosophila first instar larval brain. We first assigned cell-type identity based on known marker genes, distinguishing five major groups: neural progenitors, differentiated neurons, glia, undifferentiated neurons and non-neural cells. All major classes were further subdivided into multiple subtypes, revealing biological features of various cell-types. We further assessed transcriptional changes in response to starvation at the single-cell level. While after starvation the composition of the brain remains unaffected, transcriptional profile of several cell clusters changed. Intriguingly, different cell-types show very distinct responses to starvation, suggesting the presence of cell-specific programs for nutrition availability. Establishing a single-cell transcriptome atlas of the larval brain provides a powerful tool to explore cell diversity and assess genetic profiles from developmental, functional and behavioral perspectives.
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Affiliation(s)
| | - G Larisa Maier
- Department of BiologyUniversity of FribourgFribourgSwitzerland
| | - Rémy Bruggmann
- Interfaculty Bioinformatics UnitUniversity of BernBernSwitzerland
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8
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Hamid R, Hajirnis N, Kushwaha S, Saleem S, Kumar V, Mishra RK. Drosophila Choline transporter non-canonically regulates pupal eclosion and NMJ integrity through a neuronal subset of mushroom body. Dev Biol 2019; 446:80-93. [DOI: 10.1016/j.ydbio.2018.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/25/2018] [Accepted: 12/07/2018] [Indexed: 12/19/2022]
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9
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Mushroom Body Specific Transcriptome Analysis Reveals Dynamic Regulation of Learning and Memory Genes After Acquisition of Long-Term Courtship Memory in Drosophila. G3-GENES GENOMES GENETICS 2018; 8:3433-3446. [PMID: 30158319 PMCID: PMC6222587 DOI: 10.1534/g3.118.200560] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The formation and recall of long-term memory (LTM) requires neuron activity-induced gene expression. Transcriptome analysis has been used to identify genes that have altered expression after memory acquisition, however, we still have an incomplete picture of the transcriptional changes that are required for LTM formation. The complex spatial and temporal dynamics of memory formation creates significant challenges in defining memory-relevant gene expression changes. The Drosophila mushroom body (MB) is a signaling hub in the insect brain that integrates sensory information to form memories across several different experimental memory paradigms. Here, we performed transcriptome analysis in the MB at two time points after the acquisition of LTM: 1 hr and 24 hr. The MB transcriptome was compared to biologically paired whole head (WH) transcriptomes. In both, we identified more transcript level changes at 1 hr after memory acquisition (WH = 322, MB = 302) than at 24 hr (WH = 23, MB = 20). WH samples showed downregulation of developmental genes and upregulation of sensory response genes. In contrast, MB samples showed vastly different changes in transcripts involved in biological processes that are specifically related to LTM. MB-downregulated genes were highly enriched for metabolic function. MB-upregulated genes were highly enriched for known learning and memory processes, including calcium-mediated neurotransmitter release and cAMP signaling. The neuron activity inducible genes Hr38 and sr were also specifically induced in the MB. These results highlight the importance of sampling time and cell type in capturing biologically relevant transcript level changes involved in learning and memory. Our data suggests that MB cells transiently upregulate known memory-related pathways after memory acquisition and provides a critical frame of reference for further investigation into the role of MB-specific gene regulation in memory.
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10
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Hida N, Aboukilila MY, Burow DA, Paul R, Greenberg MM, Fazio M, Beasley S, Spitale RC, Cleary MD. EC-tagging allows cell type-specific RNA analysis. Nucleic Acids Res 2017. [PMID: 28641402 PMCID: PMC5587779 DOI: 10.1093/nar/gkx551] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Purification of cell type-specific RNAs remains a significant challenge. One solution involves biosynthetic tagging of target RNAs. RNA tagging via incorporation of 4-thiouracil (TU) in cells expressing transgenic uracil phosphoribosyltransferase (UPRT), a method known as TU-tagging, has been used in multiple systems but can have limited specificity due to endogenous pathways of TU incorporation. Here, we describe an alternative method that requires the activity of two enzymes: cytosine deaminase (CD) and UPRT. We found that the sequential activity of these enzymes converts 5-ethynylcytosine (EC) to 5-ethynyluridine monophosphate that is subsequently incorporated into nascent RNAs. The ethynyl group allows efficient detection and purification of tagged RNAs. We show that ‘EC-tagging’ occurs in tissue culture cells and Drosophila engineered to express CD and UPRT. Additional control can be achieved through a split-CD approach in which functional CD is reconstituted from independently expressed fragments. We demonstrate the sensitivity and specificity of EC-tagging by obtaining cell type-specific gene expression data from intact Drosophila larvae, including transcriptome measurements from a small population of central brain neurons. EC-tagging provides several advantages over existing techniques and should be broadly useful for investigating the role of differential RNA expression in cell identity, physiology and pathology.
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Affiliation(s)
- Naoki Hida
- Molecular and Cell Biology Unit, Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
| | - Mohamed Y Aboukilila
- Molecular and Cell Biology Unit, Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
| | - Dana A Burow
- Molecular and Cell Biology Unit, Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
| | - Rakesh Paul
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Marc M Greenberg
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Michael Fazio
- Department of Pharmaceutical Sciences and Department of Chemistry, University of California, Irvine, CA 92697, USA
| | - Samantha Beasley
- Department of Pharmaceutical Sciences and Department of Chemistry, University of California, Irvine, CA 92697, USA
| | - Robert C Spitale
- Department of Pharmaceutical Sciences and Department of Chemistry, University of California, Irvine, CA 92697, USA
| | - Michael D Cleary
- Molecular and Cell Biology Unit, Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
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11
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Immunolocalization of the vesicular acetylcholine transporter in larval and adult Drosophila neurons. Neurosci Lett 2017; 643:76-83. [PMID: 28188850 DOI: 10.1016/j.neulet.2017.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/20/2017] [Accepted: 02/06/2017] [Indexed: 11/21/2022]
Abstract
Vesicular acetylcholine transporter (VAChT) function is essential for organismal survival, mediating the packaging of acetylcholine (ACh) for exocytotic release. However, its expression pattern in the Drosophila brain has not been fully elucidated. To investigate the localization of VAChT, we developed an antibody against the C terminal region of the protein and we show that this antibody recognizes a 65KDa protein corresponding to VAChT on an immunoblot in both Drosophila head homogenates and in Schneider 2 cells. Further, we report for the first time the expression of VAChT in the antennal lobe and ventral nerve cord of Drosophila larva; and we independently confirm the expression of the protein in mushroom bodies and optic lobes of adult Drosophila. Importantly, we show that VAChT co-localizes with a synaptic vesicle marker in vivo, confirming previous reports of the localization of VAChT to synaptic terminals. Together, these findings help establish the vesicular localization of VAChT in cholinergic neurons in Drosophila and present an important molecular tool with which to dissect the function of the transporter in vivo.
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12
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Barnstedt O, Owald D, Felsenberg J, Brain R, Moszynski JP, Talbot CB, Perrat PN, Waddell S. Memory-Relevant Mushroom Body Output Synapses Are Cholinergic. Neuron 2016; 89:1237-1247. [PMID: 26948892 PMCID: PMC4819445 DOI: 10.1016/j.neuron.2016.02.015] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 01/04/2016] [Accepted: 01/27/2016] [Indexed: 11/17/2022]
Abstract
Memories are stored in the fan-out fan-in neural architectures of the mammalian cerebellum and hippocampus and the insect mushroom bodies. However, whereas key plasticity occurs at glutamatergic synapses in mammals, the neurochemistry of the memory-storing mushroom body Kenyon cell output synapses is unknown. Here we demonstrate a role for acetylcholine (ACh) in Drosophila. Kenyon cells express the ACh-processing proteins ChAT and VAChT, and reducing their expression impairs learned olfactory-driven behavior. Local ACh application, or direct Kenyon cell activation, evokes activity in mushroom body output neurons (MBONs). MBON activation depends on VAChT expression in Kenyon cells and is blocked by ACh receptor antagonism. Furthermore, reducing nicotinic ACh receptor subunit expression in MBONs compromises odor-evoked activation and redirects odor-driven behavior. Lastly, peptidergic corelease enhances ACh-evoked responses in MBONs, suggesting an interaction between the fast- and slow-acting transmitters. Therefore, olfactory memories in Drosophila are likely stored as plasticity of cholinergic synapses. Mushroom body Kenyon cell function requires ChAT and VAChT expression Kenyon cell-released acetylcholine drives mushroom body output neurons Blocking nicotinic receptors impairs mushroom body output neuron activation Acetylcholine interacts with coreleased neuropeptide
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Affiliation(s)
- Oliver Barnstedt
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - David Owald
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
| | - Johannes Felsenberg
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Ruth Brain
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - John-Paul Moszynski
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Clifford B Talbot
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Paola N Perrat
- Department of Neurobiology, UMass Medical School, Worcester, MA 01605, USA
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
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13
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Hige T, Aso Y, Rubin GM, Turner GC. Plasticity-driven individualization of olfactory coding in mushroom body output neurons. Nature 2015; 526:258-62. [PMID: 26416731 PMCID: PMC4860018 DOI: 10.1038/nature15396] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 08/11/2015] [Indexed: 12/18/2022]
Abstract
Although all sensory circuits ascend to higher brain areas where stimuli are represented in sparse, stimulus-specific activity patterns, relatively little is known about sensory coding on the descending side of neural circuits, as a network converges. In insects, mushroom bodies (MBs) have been an important model system for studying sparse coding in the olfactory system1–3, where this format is important for accurate memory formation4–6. In Drosophila, it has recently been shown that the 2000 Kenyon cells (KCs) of the MB converge onto a population of only 35 MB output neurons (MBONs), that fall into 22 anatomically distinct cell types7,8. Here we provide the first comprehensive view of olfactory representations at the fourth layer of the circuit, where we find a clear transition in the principles of sensory coding. We show that MBON tuning curves are highly correlated with one another. This is in sharp contrast to the process of progressive decorrelation of tuning in the earlier layers of the circuit2,9. Instead, at the population level, odor representations are reformatted so that positive and negative correlations arise between representations of different odors. At the single-cell level, we show that uniquely identifiable MBONs display profoundly different tuning across different animals, but tuning of the same neuron across the two hemispheres of an individual fly was nearly identical. Thus, individualized coordination of tuning arises at this level of the olfactory circuit. Furthermore, we find that this individualization is an active process that requires a learning-related gene, rutabaga. Ultimately, neural circuits have to flexibly map highly stimulus-specific information in sparse layers onto a limited number of different motor outputs. The reformatting of sensory representations we observe here may mark the beginning of this sensory-motor transition in the olfactory system.
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Affiliation(s)
- Toshihide Hige
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia 20147, USA
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia 20147, USA
| | - Glenn C Turner
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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14
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Drosophila melanogaster as a genetic model system to study neurotransmitter transporters. Neurochem Int 2014; 73:71-88. [PMID: 24704795 DOI: 10.1016/j.neuint.2014.03.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 12/30/2022]
Abstract
The model genetic organism Drosophila melanogaster, commonly known as the fruit fly, uses many of the same neurotransmitters as mammals and very similar mechanisms of neurotransmitter storage, release and recycling. This system offers a variety of powerful molecular-genetic methods for the study of transporters, many of which would be difficult in mammalian models. We review here progress made using Drosophila to understand the function and regulation of neurotransmitter transporters and discuss future directions for its use.
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15
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Anne C, Gasnier B. Vesicular neurotransmitter transporters: mechanistic aspects. CURRENT TOPICS IN MEMBRANES 2014; 73:149-74. [PMID: 24745982 DOI: 10.1016/b978-0-12-800223-0.00003-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Secondary transporters driven by a V-type H⁺-ATPase accumulate nonpeptide neurotransmitters into synaptic vesicles. Distinct transporter families are involved depending on the neurotransmitter. Monoamines and acetylcholine on the one hand, and glutamate and ATP on the other hand, are accumulated by SLC18 and SLC17 transporters, respectively, which belong to the major facilitator superfamily (MFS). GABA and glycine accumulate through a common SLC32 transporter from the amino acid/polyamine/organocation (APC) superfamily. Although crystallographic structures are not yet available for any vesicular transporter, homology modeling studies of MFS-type vesicular transporters based on distantly related bacterial structures recently provided significant advances, such as the characterization of substrate-binding pockets or the identification of spatial clusters acting as hinge points during the alternating-access cycle. However, several basic issues, such as the ion stoichiometry of vesicular amino acid transporters, remain unsettled.
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Affiliation(s)
- Christine Anne
- Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8192, Centre Universitaire des Saints-Pères, Paris, France
| | - Bruno Gasnier
- Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8192, Centre Universitaire des Saints-Pères, Paris, France.
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SLC18: Vesicular neurotransmitter transporters for monoamines and acetylcholine. Mol Aspects Med 2013; 34:360-72. [PMID: 23506877 DOI: 10.1016/j.mam.2012.07.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 05/29/2012] [Indexed: 01/06/2023]
Abstract
The exocytotic release of neurotransmitters requires active transport into synaptic vesicles and other types of secretory vesicles. Members of the SLC18 family perform this function for acetylcholine (SLC18A3, the vesicular acetylcholine transporter or VAChT) and monoamines such as dopamine and serotonin (SLC18A1 and 2, the vesicular monoamine transporters VMAT1 and 2, respectively). To date, no specific diseases have been attributed to a mutation in an SLC18 family member; however, polymorphisms in SLC18A1 and SLC18A2 may confer risk for some neuropsychiatric disorders. Additional members of this family include SLC18A4, expressed in insects, and SLC18B1, the function of which is not known. SLC18 is part of the Drug:H(+) Antiporter-1 Family (DHA1, TCID 2.A.1.2) within the Major Facilitator Superfamily (MFS, TCID 2.A.1).
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Short neuropeptide F acts as a functional neuromodulator for olfactory memory in Kenyon cells of Drosophila mushroom bodies. J Neurosci 2013; 33:5340-5. [PMID: 23516298 DOI: 10.1523/jneurosci.2287-12.2013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In insects, many complex behaviors, including olfactory memory, are controlled by a paired brain structure, the so-called mushroom bodies (MB). In Drosophila, the development, neuroanatomy, and function of intrinsic neurons of the MB, the Kenyon cells, have been well characterized. Until now, several potential neurotransmitters or neuromodulators of Kenyon cells have been anatomically identified. However, whether these neuroactive substances of the Kenyon cells are functional has not been clarified yet. Here we show that a neuropeptide precursor gene encoding four types of short neuropeptide F (sNPF) is required in the Kenyon cells for appetitive olfactory memory. We found that activation of Kenyon cells by expressing a thermosensitive cation channel (dTrpA1) leads to a decrease in sNPF immunoreactivity in the MB lobes. Targeted expression of RNA interference against the sNPF precursor in Kenyon cells results in a highly significant knockdown of sNPF levels. This knockdown of sNPF in the Kenyon cells impairs sugar-rewarded olfactory memory. This impairment is not due to a defect in the reflexive sugar preference or odor response. Consistently, knockdown of sNPF receptors outside the MB causes deficits in appetitive memory. Altogether, these results suggest that sNPF is a functional neuromodulator released by Kenyon cells.
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Henry GL, Davis FP, Picard S, Eddy SR. Cell type-specific genomics of Drosophila neurons. Nucleic Acids Res 2012; 40:9691-704. [PMID: 22855560 PMCID: PMC3479168 DOI: 10.1093/nar/gks671] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Many tools are available to analyse genomes but are often challenging to use in a cell type–specific context. We have developed a method similar to the isolation of nuclei tagged in a specific cell type (INTACT) technique [Deal,R.B. and Henikoff,S. (2010) A simple method for gene expression and chromatin profiling of individual cell types within a tissue. Dev. Cell, 18, 1030–1040; Steiner,F.A., Talbert,P.B., Kasinathan,S., Deal,R.B. and Henikoff,S. (2012) Cell-type-specific nuclei purification from whole animals for genome-wide expression and chromatin profiling. Genome Res., doi:10.1101/gr.131748.111], first developed in plants, for use in Drosophila neurons. We profile gene expression and histone modifications in Kenyon cells and octopaminergic neurons in the adult brain. In addition to recovering known gene expression differences, we also observe significant cell type–specific chromatin modifications. In particular, a small subset of differentially expressed genes exhibits a striking anti-correlation between repressive and activating histone modifications. These genes are enriched for transcription factors, recovering those known to regulate mushroom body identity and predicting analogous regulators of octopaminergic neurons. Our results suggest that applying INTACT to specific neuronal populations can illuminate the transcriptional regulatory networks that underlie neuronal cell identity.
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Affiliation(s)
- Gilbert L Henry
- Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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