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Chen L, Liang J, Zhang Q, Yang C, Lu H, Zhang R, Chen K, Wang S, Li M, Zhang S, He N. Mulberry-derived miR168a downregulates BmMthl1 to promote physical development and fecundity in silkworms. Int J Biol Macromol 2024; 259:129077. [PMID: 38199542 DOI: 10.1016/j.ijbiomac.2023.129077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024]
Abstract
Plant-derived miRNAs and their interactions with host organisms are considered important factors in regulating host physiological processes. In this study, we investigated the interaction between the silkworm, an oligophagous insect, and its primary food source, mulberry, to determine whether mulberry-derived miRNAs can penetrate silkworm cells and regulate their functions. Our results demonstrated that miR168a from mulberry leaves enters the silkworm hemolymph and binds to the silkworm Argonaute1 BmAGO1, which is transported via vesicles secreted by silkworm cells to exert its regulatory functions. In vivo and in vitro functional studies revealed that miR168a targets the mRNA of silkworm G protein-coupled receptor, BmMthl1, thereby inhibiting its expression and activating the JNK-FoxO pathway. This activation reduces oxidative stress responses, prolongs the lifespan of silkworms, and improves their reproductive capacity. These findings highlight the challenges of replacing mulberry leaves with alternative protein sources and provide a foundation for developing silkworm germplasms suitable for factory rearing.
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Affiliation(s)
- Lin Chen
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Jiubo Liang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Qi Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Chao Yang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Hulin Lu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Renze Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Kaiying Chen
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Sheng Wang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Mingbo Li
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Shaoyu Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Ningjia He
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China.
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2
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Xiao C, M’Angale PG, Wang S, Lemieux A, Thomson T. Identifying new players in structural synaptic plasticity through dArc1 interrogation. iScience 2023; 26:108048. [PMID: 37876812 PMCID: PMC10590816 DOI: 10.1016/j.isci.2023.108048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/28/2023] [Accepted: 09/22/2023] [Indexed: 10/26/2023] Open
Abstract
The formation, expansion, and pruning of synapses, known as structural synaptic plasticity, is needed for learning and memory, and perturbation of plasticity is associated with many neurological disorders and diseases. Previously, we observed that the Drosophila homolog of Activity-regulated cytoskeleton-associated protein (dArc1), forms a capsid-like structure, associates with its own mRNA, and is transported across synapses. We demonstrated that this transfer is needed for structural synaptic plasticity. To identify mRNAs that are modified by dArc1 in presynaptic neuron and postsynaptic muscle, we disrupted the expression of dArc1 and performed genomic analysis with deep sequencing. We found that dArc1 affects the expression of genes involved in metabolism, phagocytosis, and RNA-splicing. Through immunoprecipitation we also identified potential mRNA cargos of dArc1 capsids. This study suggests that dArc1 acts as a master regulator of plasticity by affecting several distinct and highly conserved cellular processes.
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Affiliation(s)
- Cong Xiao
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - P. Githure M’Angale
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Shuhao Wang
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Adrienne Lemieux
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Travis Thomson
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
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3
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Jusyte M, Blaum N, Böhme MA, Berns MMM, Bonard AE, Vámosi ÁB, Pushpalatha KV, Kobbersmed JRL, Walter AM. Unc13A dynamically stabilizes vesicle priming at synaptic release sites for short-term facilitation and homeostatic potentiation. Cell Rep 2023; 42:112541. [PMID: 37243591 DOI: 10.1016/j.celrep.2023.112541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/10/2023] [Accepted: 05/03/2023] [Indexed: 05/29/2023] Open
Abstract
Presynaptic plasticity adjusts neurotransmitter (NT) liberation. Short-term facilitation (STF) tunes synapses to millisecond repetitive activation, while presynaptic homeostatic potentiation (PHP) of NT release stabilizes transmission over minutes. Despite different timescales of STF and PHP, our analysis of Drosophila neuromuscular junctions reveals functional overlap and shared molecular dependence on the release-site protein Unc13A. Mutating Unc13A's calmodulin binding domain (CaM-domain) increases baseline transmission while blocking STF and PHP. Mathematical modeling suggests that Ca2+/calmodulin/Unc13A interaction plastically stabilizes vesicle priming at release sites and that CaM-domain mutation causes constitutive stabilization, thereby blocking plasticity. Labeling the functionally essential Unc13A MUN domain reveals higher STED microscopy signals closer to release sites following CaM-domain mutation. Acute phorbol ester treatment similarly enhances NT release and blocks STF/PHP in synapses expressing wild-type Unc13A, while CaM-domain mutation occludes this, indicating common downstream effects. Thus, Unc13A regulatory domains integrate signals across timescales to switch release-site participation for synaptic plasticity.
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Affiliation(s)
- Meida Jusyte
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Einstein Center for Neurosciences Berlin, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Natalie Blaum
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Mathias A Böhme
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Manon M M Berns
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Alix E Bonard
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Ábel B Vámosi
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | | | - Janus R L Kobbersmed
- Department of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark; Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Alexander M Walter
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Einstein Center for Neurosciences Berlin, Charité Universitätsmedizin Berlin, Berlin, Germany; Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.
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4
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Malpe MS, McSwain LF, Kudyba K, Ng CL, Nicholson J, Brady M, Qian Y, Choksi V, Hudson AG, Parrott BB, Schulz C. G-protein signaling is required for increasing germline stem cell division frequency in response to mating in Drosophila males. Sci Rep 2020; 10:3888. [PMID: 32127590 PMCID: PMC7054589 DOI: 10.1038/s41598-020-60807-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/17/2020] [Indexed: 02/07/2023] Open
Abstract
Adult stem cells divide to renew the stem cell pool and replenish specialized cells that are lost due to death or usage. However, little is known about the mechanisms regulating how stem cells adjust to a demand for specialized cells. A failure of the stem cells to respond to this demand can have serious consequences, such as tissue loss, or prolonged recovery post injury. Here, we challenge the male germline stem cells (GSCs) of Drosophila melanogaster for the production of specialized cells, sperm cells, using mating experiments. We show that repeated mating reduced the sperm pool and increased the percentage of GSCs in M- and S-phase of the cell cycle. The increase in dividing GSCs depended on the activity of the highly conserved G-proteins. Germline expression of RNA-Interference (RNA-i) constructs against G-proteins, or a dominant negative G-protein eliminated the increase in GSC division frequency in mated males. Consistent with a role for the G-proteins in regulating GSC division frequency, RNA-i against seven out of 35 G-protein coupled receptors (GPCRs) within the germline cells also eliminated the capability of males to increase the numbers of dividing GSCs in response to mating.
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Affiliation(s)
- Manashree S Malpe
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Leon F McSwain
- Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Karl Kudyba
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Chun L Ng
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jennie Nicholson
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Maximilian Brady
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Yue Qian
- University of North Georgia, Department of Biology, Oakwood, GA, 30566, USA
| | - Vinay Choksi
- School of Medicine, Duke University, Durham, NC, 27708, USA
| | - Alicia G Hudson
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | | | - Cordula Schulz
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
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5
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Ma Z, Zhang Y, You C, Zeng X, Gao X. The role of G protein-coupled receptor-related genes in cytochrome P450-mediated resistance of the house fly, Musca domestica (Diptera: Muscidae), to imidacloprid. Insect Mol Biol 2020; 29:92-103. [PMID: 31456272 DOI: 10.1111/imb.12615] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 07/21/2019] [Accepted: 07/26/2019] [Indexed: 06/10/2023]
Abstract
Ninety-four putative G protein-coupled receptors (GPCRs) were identified in the Musca domestica genome. They were annotated and compared with their homologues in Drosophila melanogaster. Phylogenetic analyses of the GPCRs from both species revealed that several family members shared a closer relationship based on the domain architecture. The expression profiles of these genes were examined by quantitative real-time PCR amongst three strains of the house fly, a near-isogenic line strain with imidacloprid resistance (N-IRS), the corresponding susceptible strain (CSS) and another strain derived from field populations with imidacloprid resistance (IRS). We found that five GPCR genes were upregulated in the N-IRS and eight GPCR genes were upregulated in the IRS strains compared to the CSS strain. The transgenic lines of D. melanogaster with the GPCR genes (LOC101899380 in the N-IRS strain and LOC101895664 in the IRS strain) exhibited significantly increased tolerance to imidacloprid, and higher expression of cytochrome P450 genes. Bioinformatic analysis of LOC101899380 was carried out based on its full-length nucleic acid sequence and putative amino acid sequence, and it was named Methuselah-like10 (Mthl10) owing to its homology with D. melanogaster Mthl10. A cell-base cell counting kit-8 toxicity assay demonstrated that the expression of the GPCR gene LOC101899380 in Spodoptera frugiperda (Sf9) cells using a baculovirus-mediated expression system can elevate the cell tolerance to imidacloprid, indirectly supporting the hypothesis that the GPCR gene LOC101899380 plays some role in imidacloprid resistance. These results should be useful for furthering understanding of the regulatory pathway by which house flies develop resistance.
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Affiliation(s)
- Z Ma
- Department of Entomology, China Agricultural University, Beijing, China
| | - Y Zhang
- Department of Entomology, China Agricultural University, Beijing, China
| | - C You
- Department of Entomology, China Agricultural University, Beijing, China
| | - X Zeng
- Beijing Center for Diseases Prevention and Control, Beijing, China
| | - X Gao
- Department of Entomology, China Agricultural University, Beijing, China
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6
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Qin X, Jin X, Zhou K, Li H, Wang Q, Li W, Wang Q. EsGPCR89 regulates cerebral antimicrobial peptides through hemocytes in Eriocheir sinensis. Fish Shellfish Immunol 2019; 95:151-162. [PMID: 31605765 DOI: 10.1016/j.fsi.2019.10.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/02/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
G protein-coupled receptors (GPCRs) are important transmembrane receptors that participate in diverse physiological processes including metabolism, cell growth and immune processes by transmitting extracellular signals to intracellular effectors. In this study, a gene belonging to the GPCR family was cloned from Eriocheir sinensis and named EsGPCR89. The full-length gene includes an open reading frame (ORF) of 465 amino acid residues, and bioinformatic analysis confirmed the high conservation between species. EsGPCR89 was detected in various tissues of E. sinensis, and was up-regulated in brain following Staphylococcus aureus infection. Expression levels of cerebral antimicrobial peptides (AMPs) were also up-regulated following bacterial challenge, reflecting their function in cerebral immunity. Additionally, EsGPCR89 silencing in hemocytes by RNA interference, down-regulated AMPs in brain after S. aureus infection. Moreover, through Immunisation assay and Polyacrylamide gel electrophoresis (SDS-PAGE) experiments, we could infer that bacterially infected hemocytes released effectors under the regulation of EsGPCR89, thereby activating transcription of cerebral AMPs. These results demonstrate that EsGPCR89 plays important roles in cerebral antimicrobial function via hemocytes.
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Affiliation(s)
- Xiang Qin
- State Key Laboratory of Estuarine and Coastal Research, and The Laboratory of Invertebrate Immunological Defense and Reproductive Biology, School of Life Science, East China Normal University, Shanghai, PR China
| | - Xingkun Jin
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, PR China
| | - Kaimin Zhou
- State Key Laboratory of Estuarine and Coastal Research, and The Laboratory of Invertebrate Immunological Defense and Reproductive Biology, School of Life Science, East China Normal University, Shanghai, PR China
| | - Hao Li
- State Key Laboratory of Estuarine and Coastal Research, and The Laboratory of Invertebrate Immunological Defense and Reproductive Biology, School of Life Science, East China Normal University, Shanghai, PR China
| | - Qiying Wang
- State Key Laboratory of Estuarine and Coastal Research, and The Laboratory of Invertebrate Immunological Defense and Reproductive Biology, School of Life Science, East China Normal University, Shanghai, PR China
| | - Weiwei Li
- State Key Laboratory of Estuarine and Coastal Research, and The Laboratory of Invertebrate Immunological Defense and Reproductive Biology, School of Life Science, East China Normal University, Shanghai, PR China.
| | - Qun Wang
- State Key Laboratory of Estuarine and Coastal Research, and The Laboratory of Invertebrate Immunological Defense and Reproductive Biology, School of Life Science, East China Normal University, Shanghai, PR China.
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7
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Cao C, Sun L, Du H, Moural TW, Bai H, Liu P, Zhu F. Physiological functions of a methuselah-like G protein coupled receptor in Lymantria dispar Linnaeus. Pestic Biochem Physiol 2019; 160:1-10. [PMID: 31519242 DOI: 10.1016/j.pestbp.2019.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 06/13/2019] [Accepted: 07/03/2019] [Indexed: 06/10/2023]
Abstract
Insect G protein coupled receptors (GPCRs) have been identified as a highly attractive target for new generation insecticides discovery due to their critical physiological functions. However, few insect GPCRs have been functionally characterized. Here, we cloned the full length of a methuselah-like GPCR gene (Ldmthl1) from the Asian gypsy moth, Lymantria dispar. We then characterized the secondary and tertiary structures of Ldmthl1. We also predicted the global structure of this insect GPCR protein which is composed of three major domains. RNA interference of Ldmthl1 resulted in a reduction of gypsy moths' resistance to deltamethrin and suppressed expression of downstream stress-associated genes, such as P450s, glutathione S transferases, and heat shock proteins. The function of Ldmthl1 was further investigated using transgenic lines of Drosophila melanogaster. Drosophila with overexpression of Ldmthl1 showed significantly longer lifespan than control flies. Taken together, our studies revealed that the physiological functions of Ldmthl1 in L. dispar are associated with longevity and resistance to insecticide stresses. Potentially, Ldmthl1 can be used as a target for new insecticide discovery in order to manage this notorious forest pest.
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Affiliation(s)
- Chuanwang Cao
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, People's Republic of China
| | - Lili Sun
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, People's Republic of China
| | - Hui Du
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, People's Republic of China
| | - Timothy W Moural
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA
| | - Hua Bai
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Peng Liu
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, People's Republic of China
| | - Fang Zhu
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA.
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8
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Zhu D, Yang L, Huang J, Zhou F, Yang Q, Jiang S, Jiang S. The comprehensive expression analysis of the G protein-coupled receptor from Penaeus monodon indicating it participates in innate immunity and anti-ammonia nitrogen stress. Fish Shellfish Immunol 2018; 75:17-26. [PMID: 29410275 DOI: 10.1016/j.fsi.2018.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 01/09/2018] [Accepted: 01/12/2018] [Indexed: 06/07/2023]
Abstract
The G protein-coupled receptors (GPCRs) composed a superfamily that played an important role in physiological processes of crustaceans, with multiple functions such as growth and development, acting as a defense against stimulations from external factors. In this paper, one kind of GPCRs were identified from Penaeus monodon, called PmGPCR, included an open reading frame (ORF) of 1113 bp. Bioinformatic analysis showed that PmGPCR protein had the typical structure of seven transmembrane domains (7TM), especially the special Asp-Arg-Try motif (DRY motif) between the third transmembrane structures (TM3) and the second intracellular loops (IL-2) which can prove that PmGPCR belongs to the rhodopsin-like family. The analyses of phylogenetic tree indicated that the amino acid sequence of PmGPCR should be merged into Procambarus clarkiic with high identity (98%). Quantitative real-time PCR (q RT-PCR) revealed that PmGPCR mRNA was highly expressed in hepatopancreas, abdominal ganglia and lymph, in which it was significantly higher than that of other tissues (P < 0.05). In addition, the expression of PmGPCR was analyzed during three days post-stimulation with the gram-positive/negative bacteria, the mRNA expression level increased after challenged with gram - positive bacteria in hepatopancreas, lymph and intestines. During the development stages, PmGPCR showed significantly higher expression in nauplius, zoea III, mysis III and post larvae stages than that in other development stages. Meanwhile, the highest transcripts expression of PmGPCR in abdominal ganglia, hepatopancreas, lymph and intestines respectively appeared at D0, D1, D2 and D3/D4 stages of molting. High or low concentration of ammonia nitrogen up-regulated the expression level of PmGPCR at the initial stage in hepatopancreas and gill, and then down-regulated at 48 h. These results indicated PmGPCR may mediate the pathways that involved in growth and development process, survival in the adversity, in addition, provided the useful data to research GPCR-mediated physiological and biological process and explain the mechanisms to defense pathogens and anti-stress in shrimp.
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Affiliation(s)
- Dandan Zhu
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou, 510300, PR China; College of Aqua-life Science and Technology, Shanghai Ocean University, Shanghai, PR China
| | - Lishi Yang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou, 510300, PR China
| | - Jianhua Huang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou, 510300, PR China; Shenzhen Base of South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shenzhen, 518108, PR China
| | - Falin Zhou
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou, 510300, PR China
| | - Qibin Yang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou, 510300, PR China
| | - Song Jiang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou, 510300, PR China
| | - Shigui Jiang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou, 510300, PR China; Shenzhen Base of South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shenzhen, 518108, PR China.
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Abstract
A combination of liquid chromatography, ion mobility spectrometry, mass spectrometry, and database searching techniques were used to characterize the proteomes of four biological replicates of adult Drosophila melanogaster heads at seven time points across their lifespans. Based on the detection of tryptic peptides, the identities of 1281 proteins were determined. An estimate of the abundance of each protein, based on the three most intense peptide ions, shows that the quantified species vary in concentration over a factor of ~103. Compared to initial studies in the field of Drosophila proteomics, our current results show an eight-fold higher temporal protein coverage with increased quantitative accuracy. Across the lifespan, we observe a range of trends in the abundance of different proteins, including: an increase in abundance of proteins involved in oxidative phosphorylation, and the tricarboxylic acid cycle; a decrease in proteasomal proteins, as well as ribosomal proteins; and, many types of proteins, which remain relatively unchanged. For younger flies, proteomes are relatively similar within their age group. For older flies, proteome similarity decreases within their age group. These combined results illustrate a correlation between increasing age and decreasing proteostasis.
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Affiliation(s)
- Christopher J. Brown
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, United States
| | - Thomas Kaufman
- Department of Biology, Indiana University, Bloomington, IN, 47405, United States
| | - Jonathan C. Trinidad
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, United States
- Corresponding authors. (J.C. Trinidad), (D.E. Clemmer)
| | - David E. Clemmer
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, United States
- Corresponding authors. (J.C. Trinidad), (D.E. Clemmer)
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10
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Delanoue R, Meschi E, Agrawal N, Mauri A, Tsatskis Y, McNeill H, Léopold P. Drosophila insulin release is triggered by adipose Stunted ligand to brain Methuselah receptor. Science 2017; 353:1553-1556. [PMID: 27708106 DOI: 10.1126/science.aaf8430] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/24/2016] [Indexed: 12/31/2022]
Abstract
Animals adapt their growth rate and body size to available nutrients by a general modulation of insulin-insulin-like growth factor signaling. In Drosophila, dietary amino acids promote the release in the hemolymph of brain insulin-like peptides (Dilps), which in turn activate systemic organ growth. Dilp secretion by insulin-producing cells involves a relay through unknown cytokines produced by fat cells. Here, we identify Methuselah (Mth) as a secretin-incretin receptor subfamily member required in the insulin-producing cells for proper nutrient coupling. We further show, using genetic and ex vivo organ culture experiments, that the Mth ligand Stunted (Sun) is a circulating insulinotropic peptide produced by fat cells. Therefore, Sun and Mth define a new cross-organ circuitry that modulates physiological insulin levels in response to nutrients.
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Affiliation(s)
- Renald Delanoue
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), 06100 Nice, France.
| | - Eleonora Meschi
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), 06100 Nice, France
| | - Neha Agrawal
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), 06100 Nice, France
| | - Alessandra Mauri
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), 06100 Nice, France
| | - Yonit Tsatskis
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Helen McNeill
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Pierre Léopold
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), 06100 Nice, France.
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11
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Zhang Z, Wang H, Hao C, Zhang W, Yang M, Chang Y, Li M. Identification, Characterization and Expression of Methuselah-Like Genes in Dastarcus helophoroides (Coleoptera: Bothrideridae). Genes (Basel) 2016; 7:E91. [PMID: 27775676 DOI: 10.3390/genes7100091] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 10/15/2016] [Accepted: 10/17/2016] [Indexed: 11/24/2022] Open
Abstract
Dastarcus helophoroides, which has a relatively longer lifespan compared to other insects, is one of the most effective natural enemies of many large-body long-horned beetles. Methuselah (Mth) is associated with the lifespan, stress resistance, and reproduction in Drosophila melanogaster, but Mth is not present in non-drosophiline insects. A number of methuselah-like genes (mth-likes, mthls) have been identified in non-drosophiline insects, but it is still unknown whether they are present in Dastarcus helophoroides. We identified three novel mth-like genes in D. helophoroides: mth-like1, mth-like2, and mth-like5, and carried out bioinformatic analysis based on the full-length nucleic acid sequences and deduced amino acid sequences. Real-time quantitative polymerase chain reaction (RT-qPCR) showed variations in expression patterns of mth-like genes in different tissues (highly expressed in reproductive systems) and at different developmental stages, indicating that mth-likes were likely be involved in reproduction and development. The altered mRNA expression in aging adults and under oxidation, high temperature, and starvation stress, indicated that mth-like genes were likely to be involved in aging and the resistance of oxidation, high temperature, and starvation. These results characterize, for the first time, the basic properties of three mth-like genes from D. helophoroides that probably play important roles in development, aging, reproduction, and stress resistance.
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de Mendoza A, Jones JW, Friedrich M. Methuselah/Methuselah-like G protein-coupled receptors constitute an ancient metazoan gene family. Sci Rep 2016; 6:21801. [PMID: 26915348 DOI: 10.1038/srep21801] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/01/2016] [Indexed: 01/09/2023] Open
Abstract
Inconsistent conclusions have been drawn regarding the phylogenetic age of the Methuselah/Methuselah-like (Mth/Mthl) gene family of G protein-coupled receptors, the founding member of which regulates development and lifespan in Drosophila. Here we report the results from a targeted homolog search of 39 holozoan genomes and phylogenetic analysis of the conserved seven transmembrane domain. Our findings reveal that the Mth/Mthl gene family is ancient, has experienced numerous extinction and expansion events during metazoan evolution, and acquired the current definition of the Methuselah ectodomain during its exceptional expansion in arthropods. In addition, our findings identify Mthl1, Mthl5, Mthl14, and Mthl15 as the oldest Mth/Mthl gene family paralogs in Drosophila. Future studies of these genes have the potential to define ancestral functions of the Mth/Mthl gene family.
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Miller PB, Obrik-Uloho OT, Phan MH, Medrano CL, Renier JS, Thayer JL, Wiessner G, Bloch Qazi MC. The song of the old mother: reproductive senescence in female drosophila. Fly (Austin) 2015; 8:127-39. [PMID: 25523082 DOI: 10.4161/19336934.2014.969144] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Among animals with multiple reproductive episodes, changes in adult condition over time can have profound effects on lifetime reproductive fitness and offspring performance. The changes in condition associated with senescence can be particularly acute for females who support reproductive processes from oogenesis through fertilization. The pomace fly Drosophila melanogaster is a well-established model system for exploring the physiology of reproduction and senescence. In this review, we describe how increasing maternal age in Drosophila affects reproductive fitness and offspring performance as well as the genetic foundation of these effects. Describing the processes underlying female reproductive senescence helps us understand diverse phenomena including population demographics, condition-dependent selection, sexual conflict, and transgenerational effects of maternal condition on offspring fitness. Understanding the genetic basis of reproductive senescence clarifies the nature of life-history trade-offs as well as potential ways to augment and/or limit female fertility in a variety of organisms.
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Affiliation(s)
- Paige B Miller
- a Department of Biology ; Gustavus Adolphus College ; St Peter , MN USA
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14
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Wise A, Tenezaca L, Fernandez RW, Schatoff E, Flores J, Ueda A, Zhong X, Wu CF, Simon AF, Venkatesh T. Drosophila mutants of the autism candidate gene neurobeachin (rugose) exhibit neuro-developmental disorders, aberrant synaptic properties, altered locomotion, and impaired adult social behavior and activity patterns. J Neurogenet 2015; 29:135-43. [PMID: 26100104 DOI: 10.3109/01677063.2015.1064916] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder in humans characterized by complex behavioral deficits, including intellectual disability, impaired social interactions, and hyperactivity. ASD exhibits a strong genetic component with underlying multigene interactions. Candidate gene studies have shown that the neurobeachin (NBEA) gene is disrupted in human patients with idiopathic autism ( Castermans et al., 2003 ). The NBEA gene spans the common fragile site FRA 13A and encodes a signal scaffold protein ( Savelyeva et al., 2006 ). In mice, NBEA has been shown to be involved in the trafficking and function of a specific subset of synaptic vesicles. ( Medrihan et al., 2009 ; Savelyeva et al., 2006 ). Rugose (rg) is the Drosophila homolog of the mammalian and human NBEA. Our previous genetic and molecular analyses have shown that rg encodes an A kinase anchor protein (DAKAP 550), which interacts with components of the epidermal growth factor receptor or EGFR and Notch-mediated signaling pathways, facilitating cross talk between these and other pathways ( Shamloula et al., 2002 ). We now present functional data from studies on the larval neuromuscular junction that reveal abnormal synaptic architecture and physiology. In addition, adult rg loss-of-function mutants exhibit defective social interactions, impaired habituation, aberrant locomotion, and hyperactivity. These results demonstrate that Drosophila NBEA (rg) mutants exhibit phenotypic characteristics reminiscent of human ASD and thus could serve as a genetic model for studying ASDs.
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Affiliation(s)
- Alexandria Wise
- a Department of Biology , City College of New York , NY , USA
| | - Luis Tenezaca
- a Department of Biology , City College of New York , NY , USA
| | - Robert W Fernandez
- b Department of Molecular Biophysics and Biochemistry , Yale University , New Haven, Connecticut , USA
| | - Emma Schatoff
- a Department of Biology , City College of New York , NY , USA
| | - Julian Flores
- a Department of Biology , City College of New York , NY , USA
| | - Atsushi Ueda
- c Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Xiaotian Zhong
- c Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Chun-Fang Wu
- c Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Anne F Simon
- d Department of Biology,Western University , Ontario , Canada
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Pandey A, Khatoon R, Saini S, Vimal D, Patel DK, Narayan G, Chowdhuri DK. Efficacy of methuselah gene mutation toward tolerance of dichlorvos exposure in Drosophila melanogaster. Free Radic Biol Med 2015; 83:54-65. [PMID: 25746179 DOI: 10.1016/j.freeradbiomed.2015.02.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 11/19/2022]
Abstract
Adverse reports on the exposure of organisms to dichlorvos (DDVP; an organophosphate insecticide) necessitate studies of organismal resistance/tolerance by way of pharmacological or genetic means. In the context of genetic modulation, a mutation in methuselah (mth; encodes a class II G-protein-coupled receptor (GPCR)) is reported to extend (~35%) the life span of Drosophila melanogaster and enhance their resistance to oxidative stress induced by paraquat exposure (short term, high level). A lack of studies on organismal tolerance of DDVP by genetic modulation prompted us to examine the protective efficacy of mth mutation in exposed Drosophila. Flies were exposed to 1.5 and 15.0 ng/ml DDVP for 12-48 h to examine oxidative stress endpoints and chemical resistance. After prolonged exposure of flies to DDVP, antioxidant enzyme activities, oxidative stress, glutathione content, and locomotor performance were assayed at various days (0, 10, 20, 30, 40, 50) of age. Flies with the mth mutation (mth(1)) showed improved chemical resistance and rescued redox impairment after acute DDVP exposure. Exposed mth(1) flies exhibited improved life span along with enhanced antioxidant enzyme activities and rescued oxidative perturbations and locomotor insufficiency up to middle age (~20 days) over similarly exposed w(1118) flies. However, at late (≥30 days) age, these benefits were undermined. Further, similarly exposed mth-knockdown flies showed effects similar to those observed in mth(1) flies. This study provides evidence of tolerance in organisms carrying a mth mutation against prolonged DDVP exposure and further warrants examination of similar class II GPCR signaling facets toward better organismal health.
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Affiliation(s)
- Ashutosh Pandey
- Embryotoxicology Section, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India; Department of Molecular and Human Genetics, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
| | - Rehana Khatoon
- Embryotoxicology Section, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India
| | - Sanjay Saini
- Embryotoxicology Section, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India
| | - Divya Vimal
- Embryotoxicology Section, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Campus, Lucknow, India
| | - Devendra Kumar Patel
- Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Campus, Lucknow, India; Analytical Chemistry Section, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India
| | - Gopeshwar Narayan
- Department of Molecular and Human Genetics, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
| | - Debapratim Kar Chowdhuri
- Embryotoxicology Section, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Campus, Lucknow, India.
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Shukla AK, Pragya P, Chaouhan HS, Patel D, Abdin M, Kar Chowdhuri D. A mutation in Drosophila methuselah resists paraquat induced Parkinson-like phenotypes. Neurobiol Aging 2014; 35:2419.e1-2419.e16. [DOI: 10.1016/j.neurobiolaging.2014.04.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 03/14/2014] [Accepted: 04/13/2014] [Indexed: 11/23/2022]
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Li C, Zhang Y, Yun X, Wang Y, Sang M, Liu X, Hu X, Li B. Methuselah-like genes affect development, stress resistance, lifespan and reproduction in Tribolium castaneum. Insect Mol Biol 2014; 23:587-597. [PMID: 24924269 DOI: 10.1111/imb.12107] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Methuselah (Mth) is associated with lifespan, stress resistance and reproduction in Drosophila melanogaster, but Mth is not present in nondrosophiline insects. A number of methuselah-likes (mthls) have been identified in nondrosophiline insects, but it is unknown whether the functions of mth are shared by mthls or are divergent from them. Five mthls have been identified in Tribolium castaneum. Although they have different developmental expression patterns, they all enhance resistance to starvation. Only mthl1 and mthl2 enhance resistance to high temperature, whereas mthl4 and mthl5 negatively regulate oxidative stress in T. castaneum. Unlike in the fly with mth mutation, knockdown of mthls, except mthl3, shortens the lifespan of T. castaneum. Moreover, mthl1 and mthl2 are critical for Tribolium development. mthl1 plays important roles in larval and pupal development and adult eclosion, while mthl2 is required for eclosion. Moreover, mthl1 and mthl2 silencing reduces the fertility of T. castaneum, and mthl1 and mthl4 are also essential for embryo development. In conclusion, mthls have a significant effect on insect development, lifespan, stress resistance and reproduction. These results provide experimental evidence for functional divergence among mthls/mth and clues for the signal transduction of Mthls.
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Affiliation(s)
- Chengjun Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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Cassar M, Issa AR, Riemensperger T, Petitgas C, Rival T, Coulom H, Iché-Torres M, Han KA, Birman S. A dopamine receptor contributes to paraquat-induced neurotoxicity in Drosophila. Hum Mol Genet 2014; 24:197-212. [PMID: 25158689 DOI: 10.1093/hmg/ddu430] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Long-term exposure to environmental oxidative stressors, like the herbicide paraquat (PQ), has been linked to the development of Parkinson's disease (PD), the most frequent neurodegenerative movement disorder. Paraquat is thus frequently used in the fruit fly Drosophila melanogaster and other animal models to study PD and the degeneration of dopaminergic neurons (DNs) that characterizes this disease. Here, we show that a D1-like dopamine (DA) receptor, DAMB, actively contributes to the fast central nervous system (CNS) failure induced by PQ in the fly. First, we found that a long-term increase in neuronal DA synthesis reduced DAMB expression and protected against PQ neurotoxicity. Secondly, a striking age-related decrease in PQ resistance in young adult flies correlated with an augmentation of DAMB expression. This aging-associated increase in oxidative stress vulnerability was not observed in a DAMB-deficient mutant. Thirdly, targeted inactivation of this receptor in glutamatergic neurons (GNs) markedly enhanced the survival of Drosophila exposed to either PQ or neurotoxic levels of DA, whereas, conversely, DAMB overexpression in these cells made the flies more vulnerable to both compounds. Fourthly, a mutation in the Drosophila ryanodine receptor (RyR), which inhibits activity-induced increase in cytosolic Ca(2+), also strongly enhanced PQ resistance. Finally, we found that DAMB overexpression in specific neuronal populations arrested development of the fly and that in vivo stimulation of either DNs or GNs increased PQ susceptibility. This suggests a model for DA receptor-mediated potentiation of PQ-induced neurotoxicity. Further studies of DAMB signaling in Drosophila could have implications for better understanding DA-related neurodegenerative disorders in humans.
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Affiliation(s)
- Marlène Cassar
- Genes Circuits Rhythms and Neuropathologies, Brain Plasticity Unit, CNRS, PSL Research University, ESPCI ParisTech, 10 rue Vauquelin, 75005 Paris, France
| | - Abdul-Raouf Issa
- Genes Circuits Rhythms and Neuropathologies, Brain Plasticity Unit, CNRS, PSL Research University, ESPCI ParisTech, 10 rue Vauquelin, 75005 Paris, France
| | - Thomas Riemensperger
- Genes Circuits Rhythms and Neuropathologies, Brain Plasticity Unit, CNRS, PSL Research University, ESPCI ParisTech, 10 rue Vauquelin, 75005 Paris, France
| | - Céline Petitgas
- Genes Circuits Rhythms and Neuropathologies, Brain Plasticity Unit, CNRS, PSL Research University, ESPCI ParisTech, 10 rue Vauquelin, 75005 Paris, France
| | - Thomas Rival
- Genetics and Physiopathology of Neurotransmission, Developmental Biology Institute of Marseille-Luminy, CNRS, Université de la Méditerranée, 13009 Marseille, France and
| | - Hélène Coulom
- Genetics and Physiopathology of Neurotransmission, Developmental Biology Institute of Marseille-Luminy, CNRS, Université de la Méditerranée, 13009 Marseille, France and
| | - Magali Iché-Torres
- Genetics and Physiopathology of Neurotransmission, Developmental Biology Institute of Marseille-Luminy, CNRS, Université de la Méditerranée, 13009 Marseille, France and
| | - Kyung-An Han
- Department of Biological Sciences, Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Serge Birman
- Genes Circuits Rhythms and Neuropathologies, Brain Plasticity Unit, CNRS, PSL Research University, ESPCI ParisTech, 10 rue Vauquelin, 75005 Paris, France Genetics and Physiopathology of Neurotransmission, Developmental Biology Institute of Marseille-Luminy, CNRS, Université de la Méditerranée, 13009 Marseille, France and
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Petrosyan A, Gonçalves ÓF, Hsieh IH, Saberi K. Improved functional abilities of the life-extended Drosophila mutant Methuselah are reversed at old age to below control levels. Age (Dordr) 2014; 36:213-21. [PMID: 23913251 PMCID: PMC3889883 DOI: 10.1007/s11357-013-9568-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 07/12/2013] [Indexed: 06/02/2023]
Abstract
Methuselah (mth) is a chromosome 3 Drosophila mutant with an increased lifespan. A large number of studies have investigated the genetic, molecular, and biochemical mechanisms of the mth gene. Much less is known about the effects of mth on preservation of sensorimotor abilities throughout Drosophila's lifespan, particularly in late life. The current study investigated functional senescence in mth and its parental-control line (w1118) in two experiments that measured age-dependent changes in flight functions and locomotor activity. In experiment 1, a total of 158 flies (81 mth and 77 controls) with an age range from 10 to 70 days were individually tethered under an infrared laser-sensor system that allowed monitoring of flight duration during phototaxic flight. We found that mth has a statistically significant advantage in maintaining continuous flight over control flies at age 10 days, but not during middle and late life. At age 70 days, the trend reversed and parental control flies had a small but significant advantage, suggesting an interaction between age and genotype in the ability to sustain flight. In experiment 2, a total of 173 different flies (97 mth and 76 controls) with an age range from 50 to 76 days were individually placed in a large well-lit arena (60 × 45 cm) and their locomotor activity quantified as the distance walked in a 1-min period. Results showed that mth flies had lower levels of locomotor activity relative to controls at ages 50 and 60 days. These levels converged for the two genotypes at the oldest ages tested. Findings show markedly different patterns of functional decline for the mth line relative to those previously reported for other life-extended genotypes, suggesting that different life-extending genes have dissimilar effects on preservation of sensory and motor abilities throughout an organism's lifespan.
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Affiliation(s)
- Agavni Petrosyan
- />Department of Cognitive Sciences, University of California, Irvine, CA 92697-5100 USA
- />Neuropsychophysiology Lab, CIPsi, School of Psychology, University of Minho, Braga, Portugal
| | - Óscar F. Gonçalves
- />Neuropsychophysiology Lab, CIPsi, School of Psychology, University of Minho, Braga, Portugal
- />Department of Counseling & Applied Educational Psychology, Bouvé College of Health Sciences, Northeastern University, Boston, USA
| | - I-Hui Hsieh
- />Institute of Cognitive Neuroscience, National Central University, Jhongli City, Taiwan
| | - Kourosh Saberi
- />Department of Cognitive Sciences, University of California, Irvine, CA 92697-5100 USA
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Araújo AR, Reis M, Rocha H, Aguiar B, Morales-Hojas R, Macedo-Ribeiro S, Fonseca NA, Reboiro-Jato D, Reboiro-Jato M, Fdez-Riverola F, Vieira CP, Vieira J. The Drosophila melanogaster methuselah gene: a novel gene with ancient functions. PLoS One 2013; 8:e63747. [PMID: 23696853 PMCID: PMC3655951 DOI: 10.1371/journal.pone.0063747] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/05/2013] [Indexed: 01/10/2023] Open
Abstract
The Drosophila melanogaster G protein-coupled receptor gene, methuselah (mth), has been described as a novel gene that is less than 10 million years old. Nevertheless, it shows a highly specific expression pattern in embryos, larvae, and adults, and has been implicated in larval development, stress resistance, and in the setting of adult lifespan, among others. Although mth belongs to a gene subfamily with 16 members in D. melanogaster, there is no evidence for functional redundancy in this subfamily. Therefore, it is surprising that a novel gene influences so many traits. Here, we explore the alternative hypothesis that mth is an old gene. Under this hypothesis, in species distantly related to D. melanogaster, there should be a gene with features similar to those of mth. By performing detailed phylogenetic, synteny, protein structure, and gene expression analyses we show that the D. virilis GJ12490 gene is the orthologous of mth in species distantly related to D. melanogaster. We also show that, in D. americana (a species of the virilis group of Drosophila), a common amino acid polymorphism at the GJ12490 orthologous gene is significantly associated with developmental time, size, and lifespan differences. Our results imply that GJ12490 orthologous genes are candidates for developmental time and lifespan differences in Drosophila in general.
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Affiliation(s)
- Ana Rita Araújo
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Micael Reis
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Helder Rocha
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Bruno Aguiar
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Ramiro Morales-Hojas
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Sandra Macedo-Ribeiro
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Nuno A. Fonseca
- Center of Research in Advanced Computing Systems (CRACS-INESC Porto), Universidade do Porto, Porto, Portugal
- EMBL-European Bioinformatics Institute, Hinxton, Cambridge, United Kingdom
| | | | | | | | - Cristina P. Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Jorge Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- * E-mail:
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Gimenez LED, Ghildyal P, Fischer KE, Hu H, Ja WW, Eaton BA, Wu Y, Austad SN, Ranjan R. Modulation of methuselah expression targeted to Drosophila insulin-producing cells extends life and enhances oxidative stress resistance. Aging Cell 2013; 12:121-9. [PMID: 23121290 DOI: 10.1111/acel.12027] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2012] [Indexed: 01/14/2023] Open
Abstract
Ubiquitously reduced signaling via Methuselah (MTH), a G-protein-coupled receptor (GPCR) required for neurosecretion, has previously been reported to extend life and enhance stress resistance in flies. Whether these effects are due to reduced MTH signalling in specific tissues remains unknown. We determined that reduced expression of mth targeted to the insulin-producing cells (IPCs) of the fly brain was sufficient to extend life and enhance oxidative stress resistance. Paradoxically, we discovered that overexpression of mth targeted to the same cells has similar phenotypic effects to reduced expression due to MTH's interaction with β-arrestin, which uncouples GPCRs from their G-proteins. We confirmed the functional relationship between MTH and β-arrestin by finding that IPC-targeted overexpression of β-arrestin alone mimics the longevity phenotype of reduced MTH signaling. As reduced MTH signaling also inhibits insulin secretion from the IPCs, the most parsimonious mechanistic explanation of its longevity and stress-resistance enhancement might be through reduced insulin/IGF signaling (IIS). However, examination of phenotypic features of long-lived IPC-mth modulated flies as well as several downstream IIS targets implicates enhanced activity of the JNK stress-resistance pathway more directly than insulin signaling in the longevity and stress-resistance phenotypes.
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Affiliation(s)
- Luis E. D. Gimenez
- Department of Pharmacology; University of Texas Health Science Center San Antonio; San Antonio; TX; 78245; USA
| | - Parakashtha Ghildyal
- Department of Pharmacology; University of Texas Health Science Center San Antonio; San Antonio; TX; 78245; USA
| | - Kathleen E. Fischer
- Department of Physiology; University of Texas Health Science Center San Antonio; San Antonio; TX; 78229; USA
| | - Hongxiang Hu
- Department of Pharmacology; University of Texas Health Science Center San Antonio; San Antonio; TX; 78245; USA
| | - William W. Ja
- Department of Metabolism & Aging; The Scripps Research Institute; Jupiter; FL; 33458; USA
| | - Benjamin A. Eaton
- Department of Physiology; University of Texas Health Science Center San Antonio; San Antonio; TX; 78229; USA
| | - Yimin Wu
- Department of Physiology; University of Texas Health Science Center San Antonio; San Antonio; TX; 78229; USA
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Patel MV, Hallal DA, Jones JW, Bronner DN, Zein R, Caravas J, Husain Z, Friedrich M, Vanberkum MFA. Dramatic expansion and developmental expression diversification of the methuselah gene family during recent Drosophila evolution. J Exp Zool B Mol Dev Evol 2012; 318:368-87. [PMID: 22711569 DOI: 10.1002/jez.b.22453] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Functional studies of the methuselah/methuselah-like (mth/mthl) gene family have focused on the founding member mth, but little is known regarding the developmental functions of this receptor or any of its paralogs. We undertook a comprehensive analysis of developmental expression and sequence divergence in the mth/mthl gene family. Using in situ hybridization techniques, we detect expression of six genes (mthl1, 5, 9, 11, 13, and 14) in the embryo during gastrulation and development of the gut, heart, and lymph glands. Four receptors (mthl3, 4, 6, and 8) are expressed in the larval central nervous system, imaginal discs, or both, and two receptors (mthl10 and mth) are expressed in both embryos and larvae. Phylogenetic analysis of all mth/mthl genes in five Drosophila species, mosquito and flour beetle structured the mth/mthl family into several subclades. mthl1, 5, and 14 are present in most species, each forming a separate clade. A newly identified Drosophila mthl gene (CG31720; herein mthl15) formed another ancient clade. The remaining Drosophila receptors, including mth, are members of a large "superclade" that diversified relatively recently during dipteran evolution, in many cases within the melanogaster subgroup. Comparing the expression patterns of the mth/mthl "superclade" paralogs to the embryonic expression of the singleton ortholog in Tribolium suggests both subfunctionalization and acquisition of novel functionalities. Taken together, our findings shed novel light on mth as a young member of an adaptively evolving developmental gene family.
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Affiliation(s)
- Meghna V Patel
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
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Abstract
BACKGROUND Histone acetylation of chromatin plays a key role in promoting the dynamic transcriptional responses in neurons that influence the neuroplasticity linked to cognitive ability, yet the specific histone acetyltransferases (HATs) that create such epigenetic marks remain to be elucidated. METHODS AND FINDINGS Here we use the Drosophila neuromuscular junction (NMJ) as a well-characterized synapse model to identify HATs that control synaptic remodeling and structure. We show that the HAT dTip60 is concentrated both pre and post-synaptically within the NMJ. Presynaptic targeted reduction of dTip60 HAT activity causes a significant increase in synaptic bouton number that specifically affects type Is boutons. The excess boutons show a suppression of the active zone synaptic function marker bruchpilot, suggesting defects in neurotransmission function. Analysis of microtubule organization within these excess boutons using immunohistochemical staining to the microtubule associated protein futsch reveals a significant increase in the rearrangement of microtubule loop architecture that is required for bouton division. Moreover, α-tubulin acetylation levels of microtubules specifically extending into the terminal synaptic boutons are reduced in response to dTip60 HAT reduction. CONCLUSIONS Our results are the first to demonstrate a causative role for the HAT dTip60 in the control of synaptic plasticity that is achieved, at least in part, via regulation of the synaptic microtubule cytoskeleton. These findings have implications for dTip60 HAT dependant epigenetic mechanisms underlying cognitive function.
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Affiliation(s)
- Jessica Sarthi
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Felice Elefant
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
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Dong C, Zhang P. A putative G protein-coupled receptor involved in innate immune defense of Procambarus clarkii against bacterial infection. Comp Biochem Physiol A Mol Integr Physiol 2011; 161:95-101. [PMID: 21964155 DOI: 10.1016/j.cbpa.2011.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 09/18/2011] [Accepted: 09/19/2011] [Indexed: 01/10/2023]
Abstract
The immune functions of G protein-coupled receptor (GPCR) were widely investigated in mammals. However, limited researches on immune function of GPCRs were reported in invertebrates. In the present study, the immune functions of HP1R gene, a putative GPCR identified from red swamp crayfish Procambarus clarkii were reported. Expression of HP1R gene was significant up-regulated in response to heat-killed Aeromonas hydrophila challenge. HP1R gene silencing mediated by RNA interference significantly enhanced the susceptibility of red swamp crayfish to A. hydrophila and Vibrio alginolyticus, indicating that HP1R was required for red swamp crayfish to defend against bacterial challenge. In HP1R-silenced crayfish, increased bacterial burden and decreased THC in response to bacterial challenge were observed when compared with control crayfish. No significant difference of proPO gene expression was observed between HP1R-silenced and control crayfish after challenge with heat-killed A. hydrophila. However, PO activity in response to bacterial challenge was significantly reduced in HP1R-silenced crayfish. The results collectively indicated that HP1R was an important immune molecule which was required for red swamp crayfish to defend against bacterial infection.
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Affiliation(s)
- Chaohua Dong
- College of Life Science, Qingdao Agricultural University, Qingdao 266109, China.
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25
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Repnikova E, Koles K, Nakamura M, Pitts J, Li H, Ambavane A, Zoran MJ, Panin VM. Sialyltransferase regulates nervous system function in Drosophila. J Neurosci 2010; 30:6466-76. [PMID: 20445073 DOI: 10.1523/JNEUROSCI.5253-09.2010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In vertebrates, sialylated glycans participate in a wide range of biological processes and affect the development and function of the nervous system. While the complexity of glycosylation and the functional redundancy among sialyltransferases provide obstacles for revealing biological roles of sialylation in mammals, Drosophila possesses a sole vertebrate-type sialyltransferase, Drosophila sialyltransferase (DSiaT), with significant homology to its mammalian counterparts, suggesting that Drosophila could be a suitable model to investigate the function of sialylation. To explore this possibility and investigate the role of sialylation in Drosophila, we inactivated DSiaT in vivo by gene targeting and analyzed phenotypes of DSiaT mutants using a combination of behavioral, immunolabeling, electrophysiological, and pharmacological approaches. Our experiments demonstrated that DSiaT expression is restricted to a subset of CNS neurons throughout development. We found that DSiaT mutations result in significantly decreased life span, locomotor abnormalities, temperature-sensitive paralysis, and defects of neuromuscular junctions. Our results indicate that DSiaT regulates neuronal excitability and affects the function of a voltage-gated sodium channel. Finally, we showed that sialyltransferase activity is required for DSiaT function in vivo, which suggests that DSiaT mutant phenotypes result from a defect in sialylation of N-glycans. This work provided the first evidence that sialylation has an important biological function in protostomes, while also revealing a novel, nervous system-specific function of alpha2,6-sialylation. Thus, our data shed light on one of the most ancient functions of sialic acids in metazoan organisms and suggest a possibility that this function is evolutionarily conserved between flies and mammals.
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26
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Ja WW, Carvalho GB, Madrigal M, Roberts RW, Benzer S. The Drosophila G protein-coupled receptor, Methuselah, exhibits a promiscuous response to peptides. Protein Sci 2010; 18:2203-8. [PMID: 19672878 DOI: 10.1002/pro.221] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Methuselah (Mth) is a G protein-coupled receptor (GPCR) associated with longevity in Drosophila melanogaster. Previously, Stunted (Sun) was identified as a peptide agonist of Mth. Here, we identify two additional activators of Mth signaling: Drosophila Sex Peptide (SP) and a novel peptide (Serendipitous Peptide Activator of Mth, SPAM). Minimal functional sequences and key residues were identified from Sun and SPAM by studying truncation and alanine-scanning mutations. These peptide agonists share little sequence homology and illustrate the promiscuity of Mth for activation. mth mutants exhibit no defects in behaviors controlled by SP, casting doubt on the biological significance of Mth activation by any of these agonists, and illustrating the difficulty in applying in vitro studies to their relevance in vivo. Future studies of Mth ligands will help further our understanding of the functional interaction of agonists and GPCRs.
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Affiliation(s)
- William W Ja
- Division of Biology, California Institute of Technology, Pasadena, California 91125, USA
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27
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Flatt T, Schmidt PS. Integrating evolutionary and molecular genetics of aging. Biochim Biophys Acta 2009; 1790:951-62. [PMID: 19619612 PMCID: PMC2972575 DOI: 10.1016/j.bbagen.2009.07.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2009] [Revised: 07/07/2009] [Accepted: 07/10/2009] [Indexed: 12/25/2022]
Abstract
Aging or senescence is an age-dependent decline in physiological function, demographically manifest as decreased survival and fecundity with increasing age. Since aging is disadvantageous it should not evolve by natural selection. So why do organisms age and die? In the 1940s and 1950s evolutionary geneticists resolved this paradox by positing that aging evolves because selection is inefficient at maintaining function late in life. By the 1980s and 1990s this evolutionary theory of aging had received firm empirical support, but little was known about the mechanisms of aging. Around the same time biologists began to apply the tools of molecular genetics to aging and successfully identified mutations that affect longevity. Today, the molecular genetics of aging is a burgeoning field, but progress in evolutionary genetics of aging has largely stalled. Here we argue that some of the most exciting and unresolved questions about aging require an integration of molecular and evolutionary approaches. Is aging a universal process? Why do species age at different rates? Are the mechanisms of aging conserved or lineage-specific? Are longevity genes identified in the laboratory under selection in natural populations? What is the genetic basis of plasticity in aging in response to environmental cues and is this plasticity adaptive? What are the mechanisms underlying trade-offs between early fitness traits and life span? To answer these questions evolutionary biologists must adopt the tools of molecular biology, while molecular biologists must put their experiments into an evolutionary framework. The time is ripe for a synthesis of molecular biogerontology and the evolutionary biology of aging.
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Affiliation(s)
- Thomas Flatt
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Josef Baumann Gasse 1, A-1210 Wien, Austria
| | - Paul S. Schmidt
- University of Pennsylvania, Department of Biology, 433 South University Avenue, Philadelphia, PA 19104-6018, USA.
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28
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Russo GJ, Louie K, Wellington A, Macleod GT, Hu F, Panchumarthi S, Zinsmaier KE. Drosophila Miro is required for both anterograde and retrograde axonal mitochondrial transport. J Neurosci 2009; 29:5443-55. [PMID: 19403812 DOI: 10.1523/JNEUROSCI.5417-08.2009] [Citation(s) in RCA: 168] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Microtubule-based transport of mitochondria into dendrites and axons is vital for sustaining neuronal function. Transport along microtubule tracks proceeds in a series of plus and minus end-directed movements that are facilitated by kinesin and dynein motors. How the opposing movements are controlled to achieve effective transport over large distances remains unclear. Previous studies showed that the conserved mitochondrial GTPase Miro is required for mitochondrial transport into axons and dendrites and serves as a Ca(2+) sensor that controls mitochondrial mobility. To directly examine Miro's significance for kinesin- and/or dynein-mediated mitochondrial motility, we live-imaged movements of GFP-tagged mitochondria in larval Drosophila motor axons upon genetic manipulations of Miro. Loss of Drosophila Miro (dMiro) reduced the effectiveness of both anterograde and retrograde mitochondrial transport by selectively impairing kinesin- or dynein-mediated movements, depending on the direction of net transport. Net anterogradely transported mitochondria exhibited reduced kinesin- but normal dynein-mediated movements. Net retrogradely transported mitochondria exhibited much shorter dynein-mediated movements, whereas kinesin-mediated movements were minimally affected. In both cases, the duration of short stationary phases increased proportionally. Overexpression (OE) of dMiro also impaired the effectiveness of mitochondrial transport. Finally, loss and OE of dMiro altered the length of mitochondria in axons through a mechanistically separate pathway. We suggest that dMiro promotes effective antero- and retrograde mitochondrial transport by extending the processivity of kinesin and dynein motors according to a mitochondrion's programmed direction of transport.
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30
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Abstract
The congenital muscular dystrophies present in infancy with muscle weakness and are often associated with mental retardation. Many of these inherited disorders share a common etiology: defective O-glycosylation of alpha-dystroglycan, a component of the dystrophin complex. Protein-O-mannosyl transferase 1 (POMT1) is the first enzyme required for the glycosylation of alpha-dystroglycan, and mutations in the POMT1 gene can lead to both Walker-Warburg syndrome (WWS) and limb girdle muscular dystrophy type 2K (LGMD2K). WWS is associated with severe mental retardation and major structural abnormalities in the brain; however, LGMD2K patients display a more mild retardation with no obvious structural defects in the brain. In a screen for synaptic mutants in Drosophila, we identified mutations in the Drosophila ortholog of POMT1, dPOMT1. Because synaptic defects are a plausible cause of mental retardation, we investigated the molecular and physiological defects associated with loss of dPOMT1 in Drosophila. In dPOMT1 mutants, there is a decrease in the efficacy of synaptic transmission and a change in the subunit composition of the postsynaptic glutamate receptors at the neuromuscular junction. We demonstrate that dPOMT1 is required to glycosylate the Drosophila dystroglycan ortholog Dg in vivo, and that this is the likely cause of these synaptic defects because (1) mutations in Dg lead to similar synaptic defects and (2) genetic interaction studies suggest that dPOMT1 and Dg function in the same pathway. These results are consistent with the model that dPOMT1-dependent glycosylation of Dg is necessary for proper synaptic function and raise the possibility that similar synaptic defects occur in the congenital muscular dystrophies.
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31
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Paaby AB, Schmidt PS. Functional significance of allelic variation at methuselah, an aging gene in Drosophila. PLoS One 2008; 3:e1987. [PMID: 18414670 DOI: 10.1371/journal.pone.0001987] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Accepted: 03/04/2008] [Indexed: 12/19/2022] Open
Abstract
Background Longevity and age-specific patterns of mortality are complex traits that vary within and among taxa. Multiple candidate genes for aging have been identified in model systems by extended longevity mutant phenotypes, including the G-protein coupled receptor methuselah (mth) in D. melanogaster. These genes offer important insights into the mechanisms of lifespan determination and have been major targets of interest in the biology of aging. However, it is largely unknown whether these genes contribute to genetic variance for lifespan in natural populations, and consequently contribute to lifespan evolution. Methodology/Principle Findings For a gene to contribute to genetic variance for a particular trait, it must meet two criteria: natural allelic variation and functional differences among variants. Previous work showed that mth varies significantly among wild populations; here we assess the functional significance of wild-derived mth alleles on lifespan, fecundity and stress resistance using a quantitative complementation scheme. Our results demonstrate that mth alleles segregating in nature have a functional effect on all three traits. Conclusions/Significance These results suggest that allelic variation at mth contributes to observed differences in lifespan and correlated phenotypes in natural populations, and that evaluation of genetic diversity at candidate genes for aging can be a fruitful approach to identifying loci contributing to lifespan evolution.
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32
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Abstract
A peptide ligand for the receptor Methuselah has been identified that extends fly life span. A recent report describes the identification through the use of in vitro selection of a peptide that antagonizes Methuselah signaling in Drosophila in vitro and extends fly life span in vivo.
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Affiliation(s)
- Nazif Alic
- UCL Centre for Research on Ageing, Department of Biology, Darwin Building, University College London, Gower St, London WC1E 6BT, UK
| | - Linda Partridge
- UCL Centre for Research on Ageing, Department of Biology, Darwin Building, University College London, Gower St, London WC1E 6BT, UK
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34
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Ja WW, West AP, Delker SL, Bjorkman PJ, Benzer S, Roberts RW. Extension of Drosophila melanogaster life span with a GPCR peptide inhibitor. Nat Chem Biol 2007; 3:415-9. [PMID: 17546039 PMCID: PMC2803097 DOI: 10.1038/nchembio.2007.2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Accepted: 05/11/2007] [Indexed: 11/09/2022]
Abstract
G protein-coupled receptors (GPCRs) mediate signaling from extracellular ligands to intracellular signal transduction proteins. Methuselah (Mth) is a class B (secretin-like) GPCR, a family typified by their large, ligand-binding, N-terminal extracellular domains. Downregulation of mth increases the life span of Drosophila melanogaster; inhibitors of Mth signaling should therefore enhance longevity. We used mRNA display selection to identify high-affinity (K(d) = 15 to 30 nM) peptide ligands that bind to the N-terminal ectodomain of Mth. The selected peptides are potent antagonists of Mth signaling, and structural studies suggest that they perturb the interface between the Mth ecto- and transmembrane domains. Flies constitutively expressing a Mth antagonist peptide have a robust life span extension, which suggests that the peptides inhibit Mth signaling in vivo. Our work thus provides new life span-extending ligands for a metazoan and a general approach for the design of modulators of this important class of GPCRs.
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Affiliation(s)
- William W. Ja
- Division of Biology, 1200 E. California Blvd. 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Anthony P. West
- Division of Biology, 1200 E. California Blvd. 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Silvia L. Delker
- Division of Biology, 1200 E. California Blvd. 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Pamela J. Bjorkman
- Division of Biology, 1200 E. California Blvd. 156-29, California Institute of Technology, Pasadena, CA 91125, USA
- Howard Hughes Medical Institute, 1200 E. California Blvd. 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Seymour Benzer
- Division of Biology, 1200 E. California Blvd. 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Richard W. Roberts
- Departments of Chemistry and Chemical Engineering, University of Southern California, Los Angeles, CA 90089, USA
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35
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Petrosyan A, Hsieh IH, Saberi K. Age-dependent stability of sensorimotor functions in the life-extended Drosophila mutant methuselah. Behav Genet 2007; 37:585-94. [PMID: 17534708 DOI: 10.1007/s10519-007-9159-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 05/02/2007] [Indexed: 10/23/2022]
Abstract
Methuselah is a Drosophila mutant with a 35% increased lifespan. We examined the robustness of methuselah's sensorimotor abilities in tethered flight as a function of age in experiments designed to test visuomotor synchronization and phototaxis in simulated flight. A total of 282 flies from different age groups (4 hours to 70 days) and genotypes (mth and w1118) were individually tethered under an infrared laser-sensor system that digitally recorded wing-beat frequency (WBF). We found that mth has a higher average WBF throughout most of its lifespan compared to parental control flies (w1118) and develops flight ability at a younger age. Its WBF at late life, however, is not significantly different than that of its parental control line. We further found that mth entrains during flight to motion of a visual grating significantly better than its parental line. These findings suggest that the mth gene not only delays chronological aging but enhances sensorimotor abilities critical to survival during early and middle, but not late life.
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Affiliation(s)
- Agavni Petrosyan
- Department of Cognitive Sciences, University of California, Irvine, CA 92697-5100, USA
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36
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Dawson-Scully K, Lin Y, Imad M, Zhang J, Marin L, Horne JA, Meinertzhagen IA, Karunanithi S, Zinsmaier KE, Atwood HL. Morphological and functional effects of altered cysteine string protein at the Drosophila larval neuromuscular junction. Synapse 2007; 61:1-16. [PMID: 17068777 DOI: 10.1002/syn.20335] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The synaptic vesicle-associated cysteine string protein (CSP) is critical for neurotransmitter release at the neuromuscular junction (NMJ) of Drosophila, where the approximately 4% of mutant flies lacking CSP that survive to adulthood exhibit spastic jumping and shaking, temperature-sensitive paralysis, and premature death. Previously, it has been shown that CSP is also required for nerve terminal growth and the prevention of neurodegeneration in Drosophila and mice. At larval csp null mutant NMJs of Drosophila, intracellular recordings from the muscle showed that evoked release is significantly reduced at room temperature. However, it remained unclear whether the reduction in evoked release might be due to a loss of synaptic boutons, loss of synapses, and alterations in trafficking of vesicles to synapses. To resolve these issues, we have examined synaptic structure and function of csp null mutant NMJs at the level of single boutons. csp null mutations proportionally reduce the number of synaptic boutons of both motor neurons (1s and 1b) innervating larval muscles 6 and 7, while the number of synapses per bouton remains normal. However, focal recordings from individual synaptic boutons show that nerve-evoked neurotransmitter release is also impaired in both 1s and 1b boutons. Further, our ultrastructural analyses show that the reduction in evoked release at low stimulation frequencies is not due to a loss of synapses or to alterations in docked vesicles at synapses. Together, these data suggest that CSP promotes synaptic growth and evoked neurotransmitter release by mechanistically independent signaling pathways.
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Affiliation(s)
- Ken Dawson-Scully
- Department of Biology, University of Toronto, Mississauga, Ontario L5L 1C6, Canada.
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Baldal EA, Baktawar W, Brakefield PM, Zwaan BJ. Methuselah life history in a variety of conditions, implications for the use of mutants in longevity research. Exp Gerontol 2006; 41:1126-35. [PMID: 17064868 DOI: 10.1016/j.exger.2006.08.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Revised: 08/23/2006] [Accepted: 08/24/2006] [Indexed: 10/24/2022]
Abstract
The laboratory has yielded many long-lived mutants of several model-organisms in the past few years. Many of the resulting claims for extended longevity have been nuanced or shown to be restricted to specific conditions, including environments and genetic backgrounds. Here, we test whether the long-lived mutant fruit fly methuselah (mth(1)) displays its apparent superiority in longevity and stress resistance in different environments, at different ages and in correlated traits. The results demonstrate that stress resistance at different times in life is not consistently higher in the mutant relative to its progenitor strain (w(1118)). Furthermore, the mth(1) genotype only leads to an increase in longevity in an environment where reproduction is not stimulated. Also, virgin and mated life span were compared and showed that mating negatively affects life span, especially in the mth(1) individuals. This reduced the life span enhancing effect of the mutation to zero. This apparent environment and mating dependent trade-off between longevity and reproduction supports the disposable soma theory of ageing. We conclude that these data can only provide limited information on natural variation. The data show the need to uncover the full complexity of variation in such traits in natural environments.
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Affiliation(s)
- E A Baldal
- Institute of Biology, Leiden University, P.O. Box 9516, 2300 RA Leiden, The Netherlands
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Ueda A, Wu CF. Distinct frequency-dependent regulation of nerve terminal excitability and synaptic transmission by IA and IK potassium channels revealed by Drosophila Shaker and Shab mutations. J Neurosci 2006; 26:6238-48. [PMID: 16763031 PMCID: PMC6675186 DOI: 10.1523/jneurosci.0862-06.2006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Regulation of synaptic efficacy by nerve terminal excitability has not been extensively studied. We performed genetic and pharmacological dissections for presynaptic actions of K+ channels in Drosophila neuromuscular transmission by using electrophysiological and optical imaging techniques. Current understanding of the roles of the Shab IK channel and its mammalian Kv2 counterparts is relatively poor, as compared with that for Shaker IA channels and their Kv1 homologues. Our results revealed the striking effect of Shab mutations during high-frequency synaptic activity, as well as a functional division in synaptic regulation between the Shaker and Shab channels. Shaker channels control the basal level of release, indicated by a response to single nerve stimulation, whereas Shab channels regulate repetitive synaptic activities. These observations highlight the crucial control of nerve terminal excitability by Shaker and Shab channels to confer temporal patterns of synaptic transmission and suggest the potential participation of these channels, along with the transmitter release machinery, in activity-dependent synaptic plasticity.
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Mockett RJ, Sohal RS. Temperature-dependent trade-offs between longevity and fertility in the Drosophila mutant, methuselah. Exp Gerontol 2006; 41:566-73. [PMID: 16677788 DOI: 10.1016/j.exger.2006.03.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 03/24/2006] [Accepted: 03/27/2006] [Indexed: 10/24/2022]
Abstract
Single gene, hypomorphic mutations which extend the life spans of cold-blooded animals, such as the methuselah (mth) mutation in the fruit fly, Drosophila melanogaster, may have additional, deleterious effects on overall fitness. The hypotheses tested here were: (i) that the extension of life span by mth might be temperature-dependent, and (ii) that it might be associated with depression of reproductive output, physical activity, or the rate of metabolism. The effect of mth on life span was smaller in magnitude than reported previously, and it was both sex-specific and temperature-dependent. Female longevity was increased only at 29 degrees C, whereas for male flies the extension of mean life span diminished progressively from 15-25% 25-29 degrees C to 2% at 18 degrees C, and the survival time at 4 degrees C was decreased by 22-39%. Conversely, the lifetime reproductive output of mth mutants was decreased at 29 degrees C, but increased at 18-22 degrees C. The walking speed of mth flies was significantly elevated, but mth had no effect on the rate of oxygen consumption at 25 degrees C. Collectively, the results demonstrate that where the life span is extended, there is an offsetting effect on reproductive output, suggesting that mth induces trade-off effects and is not a direct, mechanistic regulator of the aging process.
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Affiliation(s)
- Robin J Mockett
- Department of Molecular Pharmacology and Toxicology, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90033, USA
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Poirier L, Seroude L. Genetic approaches to study aging in Drosophila melanogaster. Age (Dordr) 2005; 27:165-82. [PMID: 23598651 PMCID: PMC3458491 DOI: 10.1007/s11357-005-2919-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Revised: 03/03/2005] [Accepted: 05/15/2005] [Indexed: 06/02/2023]
Abstract
The process of aging can be described as a progressive decline in an organism's function that invariably results in death. This decline results from the activities of intrinsic genetic factors within an organism. The relative contributions of the biological and environmental components to senescence are hard to measure, however different strategies have been devised in Drosophila melanogaster to isolate and identify genetic influences on aging. These strategies include selective breeding, quantitative trait loci (QTL) mapping and single gene mutant analysis. Selective breeding effectively demonstrated a genetic, heritable component to aging while QTL mapping located regions within the Drosophila genome carrying loci that influence the aging process. Within the past decade, single gene mutant analysis has facilitated the identification of specific genes whose activities play a determinative role in Drosophila aging. This review will focus on the application of selective breeding, QTL mapping and single gene mutant analysis used in Drosophila to study aging as well as the results obtained through these strategies to date.
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Affiliation(s)
- Luc Poirier
- Department of Biology, BioSciences Complex, Queen's University, Kingston, ON K7L 3N6 Canada
| | - Laurent Seroude
- Department of Biology, BioSciences Complex, Queen's University, Kingston, ON K7L 3N6 Canada
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Bao H, Daniels RW, MacLeod GT, Charlton MP, Atwood HL, Zhang B. AP180 maintains the distribution of synaptic and vesicle proteins in the nerve terminal and indirectly regulates the efficacy of Ca2+-triggered exocytosis. J Neurophysiol 2005; 94:1888-903. [PMID: 15888532 DOI: 10.1152/jn.00080.2005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
AP180 plays an important role in clathrin-mediated endocytosis of synaptic vesicles (SVs) and has also been implicated in retrieving SV proteins. In Drosophila, deletion of its homologue, Like-AP180 (LAP), has been shown to increase the size of SVs but decrease the number of SVs and transmitter release. However, it remains elusive whether a reduction in the total vesicle pool directly affects transmitter release. Further, it is unknown whether the lap mutation also affects vesicle protein retrieval and synaptic protein localization and, if so, how it might affect exocytosis. Using a combination of electrophysiology, optical imaging, electron microscopy, and immunocytochemistry, we have further characterized the lap mutant and hereby show that LAP plays additional roles in maintaining both normal synaptic transmission and protein distribution at synapses. While increasing the rate of spontaneous vesicle fusion, the lap mutation dramatically reduces impulse-evoked transmitter release at steps downstream of calcium entry and vesicle docking. Notably, lap mutations disrupt calcium coupling to exocytosis and reduce calcium cooperativity. These results suggest a primary defect in calcium sensors on the vesicles or on the release machinery. Consistent with this hypothesis, three vesicle proteins critical for calcium-mediated exocytosis, synaptotagmin I, cysteine-string protein, and neuronal synaptobrevin, are all mislocalized to the extrasynaptic axonal regions along with Dap160, an active zone marker (nc82), and glutamate receptors in the mutant. These results suggest that AP180 is required for either recycling vesicle proteins and/or maintaining the distribution of both vesicle and synaptic proteins in the nerve terminal.
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Affiliation(s)
- Hong Bao
- Section of Neurobiology, Institute for Neuroscience, 1 University Station, The University of Texas at Austin, Austin, Texas 78712, USA
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42
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Abstract
The Drosophila larval neuromuscular system serves as a valuable model for studying the genes required for synaptic development and function. N-Ethylmaleimide sensitive factor (NSF) is a molecule known to be important in vesicular trafficking but neural expression of a dominant negative form of NSF2 induces an unexpected overgrowth of the Drosophila larval neuromuscular synapse. We have taken a genetic approach to understanding this novel phenotype by conducting a gain-of-function modifier screen to isolate genes that interact with the overgrowth phenotype. Our approach was to directly visualize the neuromuscular junction (NMJ) using a GFP transgene and screen for suppressors of NMJ overgrowth using the Gene Search collection of P-element insertions. Of the 3000 lines screened, we identified 99 lines that can partially restore the normal phenotype. Analysis of the GS element insertion sites by inverse PCR and comparison of the flanking DNA sequence to the Drosophila genome sequence revealed nearby genes for all but 10 of the 99 lines. The recovered genes, both known and predicted, include transcription factors, cytoskeletal elements, components of the ubiquitin pathway, and several signaling molecules. This collection of genes that suppress the NSF2 neuromuscular junction overgrowth phenotype is a valuable resource in our efforts to further understand the role of NSF at the synapse.
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Kidd T, Abu-Shumays R, Katzen A, Sisson JC, Jiménez G, Pinchin S, Sullivan W, Ish-Horowicz D. The epsilon-subunit of mitochondrial ATP synthase is required for normal spindle orientation during the Drosophila embryonic divisions. Genetics 2005; 170:697-708. [PMID: 15834145 PMCID: PMC1450411 DOI: 10.1534/genetics.104.037648] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We describe the maternal-effect and zygotic phenotypes of null mutations in the Drosophila gene for the epsilon-subunit of mitochondrial ATP synthase, stunted (sun). Loss of zygotic sun expression leads to a dramatic delay in the growth rate of first instar larvae and ultimately death. Embryos lacking maternally supplied sun (sun embryos) have a sixfold reduction in ATP synthase activity. Cellular analysis of sun embryos shows defects only after the nuclei have migrated to the cortex. During the cortical divisions the actin-based metaphase and cellularization furrows do not form properly, and the nuclei show abnormal spacing and division failures. The most striking abnormality is that nuclei and spindles form lines and clusters, instead of adopting a regular spacing. This is reflected in a failure to properly position neighboring nonsister centrosomes during the telophase-to-interphase transition of the cortical divisions. Our study is consistent with a role for Sun in mitochondrial ATP synthesis and suggests that reduced ATP levels selectively affect molecular motors. As Sun has been identified as the ligand for the Methuselah receptor that regulates aging, Sun may function both within and outside mitochondria.
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Affiliation(s)
- Thomas Kidd
- Developmental Genetics Laboratory, Cancer Research UK, London, England.
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44
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Claeys I, Poels J, Simonet G, Franssens V, Van Loy T, Van Hiel MB, Breugelmans B, Vanden Broeck J. Insect Neuropeptide and Peptide Hormone Receptors: Current Knowledge and Future Directions. Vitamins & Hormones 2005; 73:217-82. [PMID: 16399412 DOI: 10.1016/s0083-6729(05)73007-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Peptides form a very versatile class of extracellular messenger molecules that function as chemical communication signals between the cells of an organism. Molecular diversity is created at different levels of the peptide synthesis scheme. Peptide messengers exert their biological functions via specific signal-transducing membrane receptors. The evolutionary origin of several peptide precursor and receptor gene families precedes the divergence of the important animal Phyla. In this chapter, current knowledge is reviewed with respect to the analysis of peptide receptors from insects, incorporating many recent data that result from the sequencing of different insect genomes. Therefore, detailed information is provided on six different peptide receptor families belonging to two distinct receptor categories (i.e., the heptahelical and the single transmembrane receptors). In addition, the remaining problems, the emerging concepts, and the future prospects in this area of research are discussed.
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MESH Headings
- Animals
- Drosophila/genetics
- Drosophila/physiology
- Drosophila Proteins/genetics
- Drosophila Proteins/physiology
- Forecasting
- Frizzled Receptors/genetics
- Frizzled Receptors/physiology
- Insecta/genetics
- Insecta/physiology
- Invertebrate Hormones/genetics
- Invertebrate Hormones/physiology
- Receptor Protein-Tyrosine Kinases/physiology
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/physiology
- Receptors, Gastrointestinal Hormone/genetics
- Receptors, Gastrointestinal Hormone/physiology
- Receptors, Guanylate Cyclase-Coupled/genetics
- Receptors, Guanylate Cyclase-Coupled/physiology
- Receptors, Invertebrate Peptide/genetics
- Receptors, Invertebrate Peptide/physiology
- Receptors, Peptide/genetics
- Receptors, Peptide/physiology
- Receptors, Tachykinin/genetics
- Receptors, Tachykinin/physiology
- Receptors, Transforming Growth Factor beta/physiology
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Affiliation(s)
- Ilse Claeys
- Laboratory for Developmental Physiology, Genomics and Proteomics Department of Animal Physiology and Neurobiology, Zoological Institute K.U.Leuven, Naamsestraat 59, B-3000 Leuven, Belgium
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45
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Willson J, Amliwala K, Davis A, Cook A, Cuttle MF, Kriek N, Hopper NA, O'Connor V, Harder A, Walker RJ, Holden-Dye L. Latrotoxin receptor signaling engages the UNC-13-dependent vesicle-priming pathway in C. elegans. Curr Biol 2004; 14:1374-9. [PMID: 15296755 DOI: 10.1016/j.cub.2004.07.056] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Revised: 06/08/2004] [Accepted: 06/10/2004] [Indexed: 11/21/2022]
Abstract
alpha-latrotoxin (LTX), a 120 kDa protein in black widow spider venom, triggers massive neurotransmitter exocytosis. Previous studies have highlighted a role for both intrinsic pore-forming activity and receptor binding in the action of this toxin. Intriguingly, activation of a presynaptic G protein-coupled receptor, latrophilin, may trigger release independent of pore-formation. Here we have utilized a previously identified ligand of nematode latrophilin, emodepside, to define a latrophilin-dependent pathway for neurotransmitter release in C. elegans. In the pharyngeal nervous system of this animal, emodepside (100 nM) stimulates exocytosis and elicits pharyngeal paralysis. The pharynxes of animals with latrophilin (lat-1) gene knockouts are resistant to emodepside, indicating that emodepside exerts its high-affinity paralytic effect through LAT-1. The expression pattern of lat-1 supports the hypothesis that emodepside exerts its effect on the pharynx primarily via neuronal latrophilin. We build on these observations to show that pharynxes from animals with either reduction or loss of function mutations in Gq, phospholipaseC-beta, and UNC-13 are resistant to emodepside. The latter is a key priming molecule essential for synaptic vesicle-mediated release of neurotransmitter. We conclude that the small molecule ligand emodepside triggers latrophilin-mediated exocytosis via a pathway that engages UNC-13-dependent vesicle priming.
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Affiliation(s)
- James Willson
- Neurosciences Research Group, School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, United Kingdom
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46
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Abstract
The mechanisms through which volatile general anaesthetics exert their behavioural effects remain unclear. The accessibility of the Drosophila larval neuromuscular junction to genetic and neurophysiological analysis has made it an attractive model system for identification of anaesthetic targets. This study provides a mechanistic basis for the genetic analysis of anaesthetic action, by analysing the neurophysiological effects of the volatile anaesthetic isoflurane on axonal and synaptic function in the Drosophila larva. The most robust effect of isoflurane was a reversible decrease in the amplitude and area of glutamatergic excitatory junctional currents (EJCs) evoked at the neuromuscular junction. Isoflurane did not affect postsynaptic glutamate receptor function detectably, in that the amplitudes, areas and decay times of spontaneous miniature EJCs were unchanged at any concentration. Therefore, decreased EJC amplitude resulted from reduction of neurotransmitter release. Reduced neurotransmitter release was associated with decreased presynaptic excitability, measured as increased delay to EJC onset and reduced axonal conduction velocity. EJC amplitude was rescued to control levels by direct electrotonic stimulation of the synapse in the presence of tetrodotoxin, indicating that isoflurane inhibits neurotransmitter release by reducing presynaptic excitability. In addition, isoflurane reduced release probability, measured as increased paired-pulse facilitation. The EC(50) for suppression of larval locomotion was similar to that for reduction of transmitter release, indicating that the axonal and synaptic effects were occurring in a behaviourally relevant range. These results provide a cellular context for ongoing genetic and neurophysiological analyses of volatile anaesthetic action in Drosophila, and suggest candidate anaesthetic target molecules.
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Affiliation(s)
- David J Sandstrom
- Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health MSC 4034, Bethesda, MD 20892, USA.
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Cvejic S, Zhu Z, Felice SJ, Berman Y, Huang XY. The endogenous ligand Stunted of the GPCR Methuselah extends lifespan in Drosophila. Nat Cell Biol 2004; 6:540-6. [PMID: 15133470 DOI: 10.1038/ncb1133] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Accepted: 04/13/2004] [Indexed: 11/08/2022]
Abstract
Many extracellular signals are transmitted to the interior of the cell by receptors with seven membrane-spanning helices that trigger their effects by means of heterotrimeric guanine-nucleotide-binding regulatory proteins (G proteins). These G-protein-coupled receptors (GPCRs) control various physiological functions in evolution from pheromone-induced mating in yeast to cognition in humans. The potential role of the G-protein signalling system in the control of animal ageing has been highlighted by the genetic revelation that mutation of a GPCR encoded by methuselah extends the lifespan of adult Drosophila flies. How methuselah functions in controlling ageing is not clear. A first essential step towards the understanding of methuselah function is to determine the ligands of Methuselah. Here we report the identification and characterization of two endogenous peptide ligands of Methuselah, designated Stunted A and B. Flies with mutations in the gene encoding these ligands show an increase in lifespan and resistance to oxidative stress. We conclude that the Stunted-Methuselah system is involved in the control of animal ageing.
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Affiliation(s)
- Svetlana Cvejic
- Department of Physiology, Cornell University Weill Medical College, New York, New York 10021, USA
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48
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Coyle IP, Koh YH, Lee WCM, Slind J, Fergestad T, Littleton JT, Ganetzky B. Nervous Wreck, an SH3 Adaptor Protein that Interacts with Wsp, Regulates Synaptic Growth in Drosophila. Neuron 2004; 41:521-34. [PMID: 14980202 DOI: 10.1016/s0896-6273(04)00016-9] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2003] [Revised: 11/13/2003] [Accepted: 01/07/2004] [Indexed: 10/26/2022]
Abstract
We describe the isolation and characterization of nwk (nervous wreck), a temperature-sensitive paralytic mutant that causes excessive growth of larval neuromuscular junctions (NMJs), resulting in increased synaptic bouton number and branch formation. Ultrastructurally, mutant boutons have reduced size and fewer active zones, associated with a reduction in synaptic transmission. nwk encodes an FCH and SH3 domain-containing adaptor protein that localizes to the periactive zone of presynaptic terminals and binds to the Drosophila ortholog of Wasp (Wsp), a key regulator of actin polymerization. wsp null mutants display synaptic overgrowth similar to nwk and enhance the nwk morphological phenotype in a dose-dependent manner. Evolutionarily, Nwk belongs to a previously undescribed family of adaptor proteins that includes the human srGAPs, which regulate Rho activity downstream of Robo receptors. We propose that Nwk controls synapse morphology by regulating actin dynamics downstream of growth signals in presynaptic terminals.
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Affiliation(s)
- Ian P Coyle
- Laboratory of Genetics, University of Wisconsin, Madison, WI 53706, USA
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49
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Abstract
Stress-sensitive mutants in Drosophila have been shown to exhibit activity-dependent defects in neurotransmission. Using the neuromuscular junction (NMJ), this study investigates synaptic function more specifically in two stress-sensitive mutants: stress-sensitive B (sesB), which encodes a mitochondrial ADP/ATP translocase (ANT); and Atpalpha(2206), a conditional mutant of the Na+/K+ ATPase alpha-subunit. Mechanical shock induces a period of brief paralysis in both homozygous and double heterozygous mutants, but further analysis revealed distinct activity-dependent neurotransmission lesions in each mutant. Basal neurotransmission appeared similar to wild-type controls in both mutants under low frequency stimulation. High frequency stimulation, however, caused pronounced synaptic fatigue as well as slow and incomplete synaptic recovery in sesB mutants while Atpalpha(2206) mutants displayed an increase (25-fold) in synaptic failures. Perhaps to compensate for these activity dependent defects, the neuromuscular synapse was found to be overgrown in both mutants. Passive electrotonic stimulation, which initiates synaptic transmission independent of action potentials, ameliorated synaptic failures and resulted in increased neurotransmission amplitude in Atpalpha(2206) mutants. In addition, spontaneous synaptic vesicle fusion rates were increased in Atpalpha(2206) mutants, suggesting that, in the absence of action potential requirements, these synaptic terminals are healthy, if not hyperactive. Dye labeling studies revealed aberrant synaptic vesicle cycling in sesB mutants indicating a reduction of functional synaptic vesicles. We therefore postulate that both stress-sensitive mutants harbor unique neurotransmission defects: Atpalpha(2206) mutants are unable to maintain ionic gradients required during repetitive action potential propagation, and sesB mutants cannot maintain synaptic vesicle cycling during periods of high demand.
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Affiliation(s)
- Nick Trotta
- Department of Biological Sciences, Program in Developmental Biology, Brain Institute, VU Station B, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
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50
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Abstract
The genetic analysis of larval neuromuscular junctions (NMJs) of Drosophila has provided detailed insights into molecular mechanisms that control the morphological and physiological development of these glutamatergic synapses. However, because of the chronic defects caused by mutations, a time-resolved analysis of these mechanisms and their functional relationships has been difficult so far. In this study we provide a first temporal map of some of the molecular and cellular key processes, which are triggered in wild-type animals by natural larval locomotor activity and then mediate experience-dependent strengthening of larval NMJs. Larval locomotor activity was increased either by chronically rearing a larval culture at 29 degrees C instead of 18 or 25 degrees C or by acutely transferring larvae from a culture vial onto agar plates. Within 2 hr of enhanced locomotor activity, NMJs showed a significant potentiation of signal transmission that was rapidly reversed by an induced paralysis of the temperature-sensitive mutant parats1. Enhanced locomotor activity was also associated with a significant increase in the number of large subsynaptic translation aggregates. After 4 hr, postsynaptic DGluR-IIA glutamate receptor subunits started to transiently accumulate in ring-shaped areas around synapses, and they condensed later on, after chronic locomotor stimulation at 29 degrees C, into typical postsynaptic patches. These NMJs showed a reduced perisynaptic expression of the cell adhesion molecule Fasciclin II, an increased number of junctional boutons, and significantly more active zones. Such temporal mapping of experience-dependent adaptations at developing wild-type and mutant NMJs will provide detailed insights into the dynamic control of glutamatergic signal transmission.
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