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Ricardo PC, Arias MC, de Souza Araujo N. Decoding bee cleptoparasitism through comparative transcriptomics of Coelioxoides waltheriae and its host Tetrapedia diversipes. Sci Rep 2024; 14:12361. [PMID: 38811580 PMCID: PMC11137135 DOI: 10.1038/s41598-024-56261-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 03/04/2024] [Indexed: 05/31/2024] Open
Abstract
Cleptoparasitism, also known as brood parasitism, is a widespread strategy among bee species in which the parasite lays eggs into the nests of the host species. Even though this behavior has significant ecological implications for the dynamics of several species, little is known about the molecular pathways associated with cleptoparasitism. To shed some light on this issue, we used gene expression data to perform a comparative analysis between two solitary neotropical bees: Coelioxoides waltheriae, an obligate parasite, and their specific host Tetrapedia diversipes. We found that ortholog genes involved in signal transduction, sensory perception, learning, and memory formation were differentially expressed between the cleptoparasite and the host. We hypothesize that these genes and their associated molecular pathways are engaged in cleptoparasitism-related processes and, hence, are appealing subjects for further investigation into functional and evolutionary aspects of cleptoparasitism in bees.
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Affiliation(s)
- Paulo Cseri Ricardo
- Departamento de Genética e Biologia Evolutiva - Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
| | - Maria Cristina Arias
- Departamento de Genética e Biologia Evolutiva - Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
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2
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Ringo JM, Segal D. Altered Grooming Cycles in Transgenic Drosophila. Behav Genet 2024; 54:290-301. [PMID: 38536593 DOI: 10.1007/s10519-024-10180-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 03/14/2024] [Indexed: 04/21/2024]
Abstract
Head grooming in Drosophila consists of repeated sweeps of the legs across the head, comprising regular cycles. We used the GAL4-UAS system to study the effects of overexpressing shibirets1 and of Adar knockdown via RNA interference, on the period of head-grooming cycles in Drosophila. Overexpressing shibirets1 interferes with synaptic vesicle recycling and thus with cell communication, while Adar knockdown reduces RNA editing of neuronal transcripts for a large number of genes. All transgenic flies and their controls were tested at 22° to avoid temperature effects; in wild type, cycle frequency varied with temperature with a Q10 of 1.3. Two experiments were performed with transgenic shibirets1: (1) each fly was heat-shocked for 10 min at 30° immediately before testing at 22° and (2) flies were not heat shocked. In both experiments, cycle period was increased when shibirets1 was overexpressed in all neurons, but was not increased when shibirets1 was overexpressed in motoneurons alone. We hypothesize that grooming cycles in flies overexpressing shibirets1 are lengthened because of synaptic impairment in neural circuits that control head-grooming cycles. In flies with constitutive, pan-neuronal Adar knockdown, cycle period was more variable within individuals, but mean cycle period was not significantly altered. We conclude that RNA editing is essential for the maintenance of within-individual stereotypy of head-grooming cycles.
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Affiliation(s)
- John M Ringo
- School of Biology and Ecology, University of Maine, Orono, ME, 04473, USA.
| | - Daniel Segal
- Shmunis School of Biomedicine and Cancer Research, Sagol School of Neuroscience, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
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3
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Peng D, Zheng L, Liu D, Han C, Wang X, Yang Y, Song L, Zhao M, Wei Y, Li J, Ye X, Wei Y, Feng Z, Huang X, Chen M, Gou Y, Xue Y, Zhang L. Large-language models facilitate discovery of the molecular signatures regulating sleep and activity. Nat Commun 2024; 15:3685. [PMID: 38693116 PMCID: PMC11063160 DOI: 10.1038/s41467-024-48005-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 04/17/2024] [Indexed: 05/03/2024] Open
Abstract
Sleep, locomotor and social activities are essential animal behaviors, but their reciprocal relationships and underlying mechanisms remain poorly understood. Here, we elicit information from a cutting-edge large-language model (LLM), generative pre-trained transformer (GPT) 3.5, which interprets 10.2-13.8% of Drosophila genes known to regulate the 3 behaviors. We develop an instrument for simultaneous video tracking of multiple moving objects, and conduct a genome-wide screen. We have identified 758 fly genes that regulate sleep and activities, including mre11 which regulates sleep only in the presence of conspecifics, and NELF-B which regulates sleep regardless of whether conspecifics are present. Based on LLM-reasoning, an educated signal web is modeled for understanding of potential relationships between its components, presenting comprehensive molecular signatures that control sleep, locomotor and social activities. This LLM-aided strategy may also be helpful for addressing other complex scientific questions.
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Affiliation(s)
- Di Peng
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Liubin Zheng
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Dan Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Cheng Han
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Xin Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Yan Yang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Li Song
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Miaoying Zhao
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Yanfeng Wei
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Jiayi Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Xiaoxue Ye
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Yuxiang Wei
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Zihao Feng
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Xinhe Huang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Miaomiao Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Yujie Gou
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Yu Xue
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
- Nanjing University Institute of Artificial Intelligence Biomedicine, Nanjing, Jiangsu, 210031, China.
| | - Luoying Zhang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, Hubei, 430022, China.
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Rouyar A, Patil AA, Leon-Noreña M, Li M, Coutinho-Abreu IV, Akbari OS, Riffell JA. Transgenic line for characterizing GABA-receptor expression to study the neural basis of olfaction in the yellow-fever mosquito. Front Physiol 2024; 15:1381164. [PMID: 38606012 PMCID: PMC11008680 DOI: 10.3389/fphys.2024.1381164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/14/2024] [Indexed: 04/13/2024] Open
Abstract
The mosquito Aedes aegypti is an important vector of diseases including dengue, Zika, chikungunya, and yellow fever. Olfaction is a critical modality for mosquitoes enabling them to locate hosts, sources of nectar, and sites for oviposition. GABA is an essential neurotransmitter in olfactory processing in the insect brain, including the primary olfactory center, the antennal lobe. Previous work with Ae. aegypti has suggested that antennal lobe inhibition via GABA may be involved in the processing of odors. However, little is known about GABA receptor expression in the mosquito brain, or how they may be involved in odor attraction. In this context, generating mutants that target the mosquito's olfactory responses, and particularly the GABAergic system, is essential to achieve a better understanding of these diverse processes and olfactory coding in these disease vectors. Here we demonstrate the potential of a transgenic line using the QF2 transcription factor, GABA-B1QF2-ECFP, as a new neurogenetic tool to investigate the neural basis of olfaction in Ae. aegypti. Our results show that the gene insertion has a moderate impact on mosquito fitness. Moreover, the line presented here was crossed with a QUAS reporter line expressing the green fluorescent protein and used to determine the location of the metabotropic GABA-B1 receptor expression. We find high receptor expression in the antennal lobes, especially the cell bodies surrounding the antennal lobes. In the mushroom bodies, receptor expression was high in the Kenyon cells, but had low expression in the mushroom body lobes. Behavioral experiments testing the fruit odor attractants showed that the mutants lost their behavioral attraction. Together, these results show that the GABA-B1QF2-ECFP line provides a new tool to characterize GABAergic systems in the mosquito nervous system.
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Affiliation(s)
- Angela Rouyar
- Department of Biology, University of Washington, Seattle, WA, United States
| | - Anandrao A. Patil
- Department of Biology, University of Washington, Seattle, WA, United States
| | | | - Ming Li
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Iliano V. Coutinho-Abreu
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Omar S. Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Jeff A. Riffell
- Department of Biology, University of Washington, Seattle, WA, United States
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5
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Clabough EBD, Aspili C, Fussy WS, Ingersoll JD, Kislyakov A, Li ES, Su MJ, Wiles DB, Watson TE, Willy AJ, Thomas Vinyard H, Mollica Iii PJ, Taylor JV, Smith CW, Roark DA, Tabrani ZP, Thomas HL, Shin M, Venton BJ, Hayes D, Sipe CW. Huntingtin Plays a Role in the Physiological Response to Ethanol in Drosophila. J Huntingtons Dis 2023; 12:241-252. [PMID: 37661891 DOI: 10.3233/jhd-230581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
BACKGROUND Huntingtin (htt) protein is an essential regulator of nervous system function through its various neuroprotective and pro-survival functions, and loss of wild-type htt function is implicated in the etiology of Huntington's disease. While its pathological role is typically understood as a toxic gain-of-function, some neuronal phenotypes also result from htt loss. Therefore, it is important to understand possible roles for htt in other physiological circumstances. OBJECTIVE To elucidate the role of htt in the context of ethanol exposure, we investigated how loss of htt impacts behavioral and physiological responses to ethanol in Drosophila. METHODS We tested flies lacking htt for ethanol sensitivity and tolerance, preference for ethanol using capillary feeder assays, and recovery of mobility after intoxication. Levels of dopamine neurotransmitter and numbers of dopaminergic cells in brains lacking dhtt were also measured. RESULTS We found that dhtt-null flies are both less sensitive and more tolerant to ethanol exposure in adulthood. Moreover, flies lacking dhtt are more averse to alcohol than controls, and they recover mobility faster following acute ethanol intoxication. We showed that dhtt mediates these effects at least in part through the dopaminergic system, as dhtt is required to maintain normal levels of dopamine in the brain and normal numbers of dopaminergic cells in the adult protocerebrum. CONCLUSIONS Our results demonstrate that htt regulates the physiological response to ethanol and indicate a novel neuroprotective role for htt in the dopaminergic system, raising the possibility that it may be involved more generally in the response to toxic stimuli.
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Affiliation(s)
- Erin B D Clabough
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Christia Aspili
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - William S Fussy
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - James D Ingersoll
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Amy Kislyakov
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - Elizabeth S Li
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - Meng-Jiuan Su
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - Dustin B Wiles
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Thomas E Watson
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Aaron J Willy
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - H Thomas Vinyard
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | | | - James V Taylor
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Cody W Smith
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Dallas A Roark
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Zachary P Tabrani
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Harris L Thomas
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, USA
| | - Mimi Shin
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - B Jill Venton
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, USA
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - David Hayes
- Department of Biology, Shepherd University, Shepherdstown, WV, USA
- Department of Biology, Kansas State University, Manhattan, KS, USA
| | - Conor W Sipe
- Department of Biology, Shepherd University, Shepherdstown, WV, USA
- Department of Biology, University of Virginia, Charlottesville, VA, USA
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Abstract
One in three epilepsy cases is drug resistant, and seizures often begin in infancy, when they are life-threatening and when therapeutic options are highly limited. An important tool for prioritizing and validating genes associated with epileptic conditions, which is suitable for large-scale screening, is disease modeling in Drosophila. Approximately two-thirds of disease genes are conserved in Drosophila, and gene-specific fly models exhibit behavioral changes that are related to symptoms of epilepsy. Models are based on behavior readouts, seizure-like attacks and paralysis following stimulation, and neuronal, cell-biological readouts that are in the majority based on changes in nerve cell activity or morphology. In this review, we focus on behavioral phenotypes. Importantly, Drosophila modeling is independent of, and complementary to, other approaches that are computational and based on systems analysis. The large number of known epilepsy-associated gene variants indicates a need for efficient research strategies. We will discuss the status quo of epilepsy disease modelling in Drosophila and describe promising steps towards the development of new drugs to reduce seizure rates and alleviate other epileptic symptoms.
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Affiliation(s)
- Paul Lasko
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Department of Biology, McGill University, Montréal, Québec, Canada
| | - Kevin Lüthy
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
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Chvilicek MM, Titos I, Rothenfluh A. The Neurotransmitters Involved in Drosophila Alcohol-Induced Behaviors. Front Behav Neurosci 2020; 14:607700. [PMID: 33384590 PMCID: PMC7770116 DOI: 10.3389/fnbeh.2020.607700] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Alcohol is a widely used and abused substance with numerous negative consequences for human health and safety. Historically, alcohol's widespread, non-specific neurobiological effects have made it a challenge to study in humans. Therefore, model organisms are a critical tool for unraveling the mechanisms of alcohol action and subsequent effects on behavior. Drosophila melanogaster is genetically tractable and displays a vast behavioral repertoire, making it a particularly good candidate for examining the neurobiology of alcohol responses. In addition to being experimentally amenable, Drosophila have high face and mechanistic validity: their alcohol-related behaviors are remarkably consistent with humans and other mammalian species, and they share numerous conserved neurotransmitters and signaling pathways. Flies have a long history in alcohol research, which has been enhanced in recent years by the development of tools that allow for manipulating individual Drosophila neurotransmitters. Through advancements such as the GAL4/UAS system and CRISPR/Cas9 mutagenesis, investigation of specific neurotransmitters in small subsets of neurons has become ever more achievable. In this review, we describe recent progress in understanding the contribution of seven neurotransmitters to fly behavior, focusing on their roles in alcohol response: dopamine, octopamine, tyramine, serotonin, glutamate, GABA, and acetylcholine. We chose these small-molecule neurotransmitters due to their conservation in mammals and their importance for behavior. While neurotransmitters like dopamine and octopamine have received significant research emphasis regarding their contributions to behavior, others, like glutamate, GABA, and acetylcholine, remain relatively unexplored. Here, we summarize recent genetic and behavioral findings concerning these seven neurotransmitters and their roles in the behavioral response to alcohol, highlighting the fitness of the fly as a model for human alcohol use.
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Affiliation(s)
- Maggie M. Chvilicek
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
| | - Iris Titos
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
| | - Adrian Rothenfluh
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, United States
- Department of Human Genetics, University of Utah, Salt Lake City, UT, United States
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Mustard JA, Jones L, Wright GA. GABA signaling affects motor function in the honey bee. JOURNAL OF INSECT PHYSIOLOGY 2020; 120:103989. [PMID: 31805284 DOI: 10.1016/j.jinsphys.2019.103989] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/26/2019] [Accepted: 11/29/2019] [Indexed: 06/10/2023]
Abstract
GABA is the most common inhibitory neurotransmitter in both vertebrate and invertebrate nervous systems. In insects, inhibition plays important roles at the neuromuscular junction, in the regulation of central pattern generators, and in the modulation of information in higher brain processing centers. Additionally, increasing our understanding of the functions of GABA is important since GABAA receptors are the targets of several classes of pesticides. To investigate the role of GABA in motor function, honey bee foragers were injected with GABA or with agonists or antagonists specific for either GABAA or GABAB receptors. Compounds that activated either type of GABA receptor decreased activity levels. Bees injected with the GABAA receptor antagonist picrotoxin lost the ability to right themselves, whereas blockade of GABAB receptors led to increases in grooming. Injection with antagonists of either GABAA or GABAB receptors resulted in an increase in extended wing behavior, during which bees kept their wings out at right angles to their body rather than folded along their back. These data suggest that the GABA receptor types play distinct roles in behavior and that GABA may affect behavior at several different levels.
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Affiliation(s)
- Julie A Mustard
- Department of Biology, University of Texas Rio Grande Valley, Brownsville, TX 78520, USA.
| | - Lisa Jones
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Geraldine A Wright
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom; Department of Zoology, University of Oxford, Oxford OX1 3SZ, United Kingdom
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Ki Y, Lim C. Sleep-promoting effects of threonine link amino acid metabolism in Drosophila neuron to GABAergic control of sleep drive. eLife 2019; 8:40593. [PMID: 31313987 PMCID: PMC6636906 DOI: 10.7554/elife.40593] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 06/27/2019] [Indexed: 01/09/2023] Open
Abstract
Emerging evidence indicates the role of amino acid metabolism in sleep regulation. Here we demonstrate sleep-promoting effects of dietary threonine (SPET) in Drosophila. Dietary threonine markedly increased daily sleep amount and decreased the latency to sleep onset in a dose-dependent manner. High levels of synaptic GABA or pharmacological activation of metabotropic GABA receptors (GABAB-R) suppressed SPET. By contrast, synaptic blockade of GABAergic neurons or transgenic depletion of GABAB-R in the ellipsoid body R2 neurons enhanced sleep drive non-additively with SPET. Dietary threonine reduced GABA levels, weakened metabotropic GABA responses in R2 neurons, and ameliorated memory deficits in plasticity mutants. Moreover, genetic elevation of neuronal threonine levels was sufficient for facilitating sleep onset. Taken together, these data define threonine as a physiologically relevant, sleep-promoting molecule that may intimately link neuronal metabolism of amino acids to GABAergic control of sleep drive via the neuronal substrate of sleep homeostasis. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Yoonhee Ki
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Chunghun Lim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
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10
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Hong KB, Park Y, Suh HJ. Two combined amino acids promote sleep activity in caffeine-induced sleepless model systems. Nutr Res Pract 2018; 12:208-214. [PMID: 29854326 PMCID: PMC5974066 DOI: 10.4162/nrp.2018.12.3.208] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/08/2018] [Accepted: 03/13/2018] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND/OBJECTIVES The aim of this study was to evaluate the biological and sleep-promoting effects of combined γ-aminobutyric acid (GABA) and 5-hydroxytryptophan (5-HTP) using caffeine-induced sleepless fruit flies, ICR mice, and Sprague-Dawley rats. MATERIALS/METHODS Video-tracking analysis was applied to investigate behavioral changes of Drosophila melanogaster. Pentobarbital-induced sleep test and electroencephalogram (EEG) patterns were used for analysis of sleep latency, duration, and quantity and quality of sleep in vertebrate models. RESULTS Administration of combined GABA/5-HTP could significantly reverse the caffeine induced total distance of flies (P < 0.001). Also, individually administered and combined GABA/5-HTP significantly increased the total sleeping time in the caffeine-induced sleepless ICR mice (P < 0.001). In the caffeine-induced sleepless SD-rats, combined GABA/5-HTP showed significant differences in sleep quality between individual amino acid administrations (P < 0.05). CONCLUSIONS Taken together, we identified inhibitory effects of combined GABA/5-HTP in locomotor activity, sleep quantity and quality in caffeine-induced sleepless models, indicating that combined GABA/5-HTP may be effective in patients with insomnia by providing sufficient sleep.
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Affiliation(s)
- Ki-Bae Hong
- Department of Biological Sciences and Environmental Sciences Program, Southern Illinois University-Edwardsville, Edwardsville, IL 62026, United States
| | - Yooheon Park
- Dongguk University Research Institute of Biotechnology and Medical Converged Science, Dongguk University, Gyeonggi 10325, Korea
| | - Hyung Joo Suh
- Department of Public Health Sciences, Korea University, 145 Anam-ro, Sungbuk-gu, Seoul 02841, Korea
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11
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Sakakibara Y, Sekiya M, Fujisaki N, Quan X, Iijima KM. Knockdown of wfs1, a fly homolog of Wolfram syndrome 1, in the nervous system increases susceptibility to age- and stress-induced neuronal dysfunction and degeneration in Drosophila. PLoS Genet 2018; 14:e1007196. [PMID: 29357349 PMCID: PMC5794194 DOI: 10.1371/journal.pgen.1007196] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/01/2018] [Accepted: 01/09/2018] [Indexed: 01/08/2023] Open
Abstract
Wolfram syndrome (WS), caused by loss-of-function mutations in the Wolfram syndrome 1 gene (WFS1), is characterized by juvenile-onset diabetes mellitus, bilateral optic atrophy, and a wide spectrum of neurological and psychiatric manifestations. WFS1 encodes an endoplasmic reticulum (ER)-resident transmembrane protein, and mutations in this gene lead to pancreatic β-cell death induced by high levels of ER stress. However, the mechanisms underlying neurodegeneration caused by WFS1 deficiency remain elusive. Here, we investigated the role of WFS1 in the maintenance of neuronal integrity in vivo by knocking down the expression of wfs1, the Drosophila homolog of WFS1, in the central nervous system. Neuronal knockdown of wfs1 caused age-dependent behavioral deficits and neurodegeneration in the fly brain. Knockdown of wfs1 in neurons and glial cells resulted in premature death and significantly exacerbated behavioral deficits in flies, suggesting that wfs1 has important functions in both cell types. Although wfs1 knockdown alone did not promote ER stress, it increased the susceptibility to oxidative stress-, excitotoxicity- or tauopathy-induced behavioral deficits, and neurodegeneration. The glutamate release inhibitor riluzole significantly suppressed premature death phenotypes induced by neuronal and glial knockdown of wfs1. This study highlights the protective role of wfs1 against age-associated neurodegeneration and furthers our understanding of potential disease-modifying factors that determine susceptibility and resilience to age-associated neurodegenerative diseases. Wolfram syndrome (WS), a neurodegenerative disorder with an autosomal recessive inheritance pattern, has a variable clinical presentation that includes diabetes mellitus, optic atrophy, and a wide spectrum of neurological and psychiatric manifestations. Homozygous mutations in WFS1 are causative for WS. The prognosis of WS is poor, and most patients die prematurely with respiratory failure due to brain stem atrophy. However, the mechanisms underlying the neurological manifestations of WS remain elusive. In this study, we used the fruit fly Drosophila to examine the neurological features of WS by generating genetically modified flies harboring knockdown of wfs1, the fly homolog of WFS1, in the central nervous system. These flies developed age-dependent behavioral deficits, neurodegeneration and premature death. wfs1-deficient flies were vulnerable to various age-related stressors such as oxidative stress and excitotoxicity, and to neurodegeneration caused by Alzheimer’s disease-related toxic proteins. The premature death phenotype in wfs1-deficient flies was ameliorated by administration of riluzole, which inhibits glutamate-induced excitotoxicity. This study provides insight into the mechanisms underlying neurodegeneration not only in WS, but also in age-associated neurodegenerative diseases such as Alzheimer’s disease.
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Affiliation(s)
- Yasufumi Sakakibara
- Department of Alzheimer’s Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Michiko Sekiya
- Department of Alzheimer’s Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Naoki Fujisaki
- Department of Alzheimer’s Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
- Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3–1 Tanabe-dori, Mizuho-ku, Nagoya, Japan
| | - Xiuming Quan
- Department of Alzheimer’s Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Koichi M. Iijima
- Department of Alzheimer’s Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
- Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3–1 Tanabe-dori, Mizuho-ku, Nagoya, Japan
- * E-mail:
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12
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Rogdi Defines GABAergic Control of a Wake-promoting Dopaminergic Pathway to Sustain Sleep in Drosophila. Sci Rep 2017; 7:11368. [PMID: 28900300 PMCID: PMC5595912 DOI: 10.1038/s41598-017-11941-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 09/01/2017] [Indexed: 12/12/2022] Open
Abstract
Kohlschutter-Tönz syndrome (KTS) is a rare genetic disorder with neurological dysfunctions including seizure and intellectual impairment. Mutations at the Rogdi locus have been linked to development of KTS, yet the underlying mechanisms remain elusive. Here we demonstrate that a Drosophila homolog of Rogdi acts as a novel sleep-promoting factor by supporting a specific subset of gamma-aminobutyric acid (GABA) transmission. Rogdi mutant flies displayed insomnia-like behaviors accompanied by sleep fragmentation and delay in sleep initiation. The sleep suppression phenotypes were rescued by sustaining GABAergic transmission primarily via metabotropic GABA receptors or by blocking wake-promoting dopaminergic pathways. Transgenic rescue further mapped GABAergic neurons as a cell-autonomous locus important for Rogdi-dependent sleep, implying metabotropic GABA transmission upstream of the dopaminergic inhibition of sleep. Consistently, an agonist specific to metabotropic but not ionotropic GABA receptors titrated the wake-promoting effects of dopaminergic neuron excitation. Taken together, these data provide the first genetic evidence that implicates Rogdi in sleep regulation via GABAergic control of dopaminergic signaling. Given the strong relevance of GABA to epilepsy, we propose that similar mechanisms might underlie the neural pathogenesis of Rogdi-associated KTS.
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13
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Zmejkoski D, Petković B, Pavković-Lučić S, Prolić Z, Anđelković M, Savić T. Different responses of Drosophila subobscura isofemale lines to extremely low frequency magnetic field (50 Hz, 0.5 mT): fitness components and locomotor activity. Int J Radiat Biol 2016; 93:544-552. [PMID: 27921519 DOI: 10.1080/09553002.2017.1268281] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE Extremely low frequency (ELF) magnetic fields as essential ecological factors may induce specific responses in genetically different lines. The object of this study was to investigate the impact of the ELF magnetic field on fitness components and locomotor activity of five Drosophila subobscura isofemale (IF) lines. MATERIALS AND METHODS Each D. subobscura IF line, arbitrarily named: B16/1, B24/4, B39/1, B57/2 and B69/5, was maintained in five full-sib inbreeding generations. Their genetic structures were defined based on the mitochondrial DNA variability. Egg-first instar larvae and 1-day-old flies were exposed to an ELF magnetic field (50 Hz, 0.5 mT, 48 h) and thereafter, fitness components and locomotor activity of males and females in an open field test were observed for each selected IF line, respectively. RESULTS Exposure of egg-first instar larvae to an ELF magnetic field shortened developmental time, and did not affect the viability and sex ratio of D. subobscura IF lines. Exposure of 1-day-old males and females IF lines B16/1 and B24/4 to an ELF magnetic field significantly decreased their locomotor activity and this effect lasted longer in females than males. CONCLUSIONS These results indicate various responses of D. subobscura IF lines to the applied ELF magnetic field depending on their genetic background.
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Affiliation(s)
- Danica Zmejkoski
- a Laboratory of Materials Science, University of Belgrade, Vinča Institute of Nuclear Sciences , Belgrade , Serbia
| | - Branka Petković
- b Department of Neurophysiology, University of Belgrade, Institute for Biological Research , Belgrade , Serbia
| | - Sofija Pavković-Lučić
- c Chair of Genetics and Evolution, Faculty of Biology , University of Belgrade , Belgrade , Serbia
| | - Zlatko Prolić
- d Department of Insect Physiology and Biochemistry , University of Belgrade, Institute for Biological Research , Belgrade , Serbia
| | - Marko Anđelković
- c Chair of Genetics and Evolution, Faculty of Biology , University of Belgrade , Belgrade , Serbia.,e Department of Chemical and Biological Sciences , Serbian Academy of Sciences and Arts , Belgrade , Serbia.,f Department of Genetics of Populations and Ecogenotoxicology , University of Belgrade, Institute for Biological Research , Belgrade , Serbia
| | - Tatjana Savić
- f Department of Genetics of Populations and Ecogenotoxicology , University of Belgrade, Institute for Biological Research , Belgrade , Serbia
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14
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Hong KB, Park Y, Suh HJ. Sleep-promoting effects of a GABA/5-HTP mixture: Behavioral changes and neuromodulation in an invertebrate model. Life Sci 2016; 150:42-9. [PMID: 26921634 DOI: 10.1016/j.lfs.2016.02.086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 02/17/2016] [Accepted: 02/23/2016] [Indexed: 11/25/2022]
Abstract
AIMS This study was to investigate the sleep promoting effects of combined γ-aminobutyric acid (GABA) and 5-hydroxytryptophan (5-HTP), by examining neuronal processes governing mRNA level alterations, as well as assessing neuromodulator concentrations, in a fruit fly model. MAIN METHODS Behavioral assays were applied to investigate subjective nighttime activity, sleep episodes, and total duration of subjective nighttime sleep of two amino acids and GABA/5-HTP mixture with caffeine treated flies. Also, real-time PCR and HPLC analysis were applied to analyze the signaling pathway. KEY FINDINGS Subjective nighttime activity and sleep patterns of individual flies significantly decreased with 1% GABA treatment in conjunction with 0.1% 5-HTP treatment (p<0.001). Furthermore, GABA/5-HTP mixture resulted in significant differences between groups related to sleep patterns (40%, p<0.017) and significantly induced subjective nighttime sleep in the awake model (p<0.003). These results related to transcript levels of the GABAB receptor (GABAB-R1) and serotonin receptor (5-HT1A), compared to the control group. In addition, GABA/5-HTP mixture significantly increased GABA levels 1h and 12h following treatment (2.1 fold and 1.2 fold higher than the control, respectively) and also increased 5-HTP levels (0 h: 1.01 μg/protein, 12h: 3.45 μg/protein). SIGNIFICANCE In this regard, we successfully demonstrated that using a GABA/5-HTP mixture modulates subjective nighttime activity, sleep episodes, and total duration of subjective nighttime sleep to a greater extent than single administration of each amino acid, and that this modulation occurs via GABAergic and serotonergic signaling.
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Affiliation(s)
- Ki-Bae Hong
- Department of Public Health Sciences, Korea University, Seoul 136-713, Republic of Korea
| | - Yooheon Park
- Dongguk University Research Institute of Biotechnology, Goyang 10326, Republic of Korea.
| | - Hyung Joo Suh
- Department of Public Health Sciences, Korea University, Seoul 136-713, Republic of Korea.
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15
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Abstract
Drosophila melanogaster is an incredibly versatile organism capable of both innate and higher-order behaviors. These behaviors offer not only a way to assay whether or not the animal is physiologically compromised (e.g., feeding, locomotion), but also serve to assess changes in centrally mediated functions. Here we describe several high throughput, reproducible, yet inexpensive and facile behavioral assays for both larval and adult Drosophila. The larval assays all employ an agar substrate in a petri dish; the adult assays are grouped into "vial-based" and "arena-based" paradigms. While these protocols are largely designed to assess individual animals, they are sufficiently rapid that ample numbers can be tested to determine behavioral significance. Importantly, this also allows for one to control for reproductive status, age, and sex, since these factors all have a significant impact on adult behaviors. In general, it is best to designate a dedicated area for any assay, so that lighting conditions are consistent, and all animals should be tested at roughly the same time each day to minimize circadian fluctuations. Temperature and humidity should also be maintained at a constant level to minimize variability in the assays.
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Affiliation(s)
- Wendi S Neckameyer
- Department of Pharmacological and Physiological Science, St Louis University School of Medicine, 1402 South Grand Boulevard, St. Louis, MO, 63104, USA.
| | - Parag Bhatt
- Department of Pharmacological and Physiological Science, St Louis University School of Medicine, 1402 South Grand Boulevard, St. Louis, MO, 63104, USA
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16
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Zheng JC, Tham CT, Keatings K, Fan S, Liou AYC, Numata Y, Allan D, Numata M. Secretory Carrier Membrane Protein (SCAMP) deficiency influences behavior of adult flies. Front Cell Dev Biol 2014; 2:64. [PMID: 25478561 PMCID: PMC4235465 DOI: 10.3389/fcell.2014.00064] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 10/17/2014] [Indexed: 12/21/2022] Open
Abstract
Secretory Carrier Membrane Proteins (SCAMPs) are a group of tetraspanning integral membrane proteins evolutionarily conserved from insects to mammals and plants. Mammalian genomes contain five SCAMP genes SCAMP1-SCAMP5 that regulate membrane dynamics, most prominently membrane-depolarization and Ca2+-induced regulated secretion, a key mechanism for neuronal and neuroendocrine signaling. However, the biological role of SCAMPs has remained poorly understood primarily owing to the lack of appropriate model organisms and behavior assays. Here we generate Drosophila Scamp null mutants and show that they exhibit reduced lifespan and behavioral abnormalities including impaired climbing, deficiency in odor associated long-term memory, and a susceptibility to heat-induced seizures. Neuron-specific restoration of Drosophila Scamp rescues all Scamp null behavioral phenotypes, indicating that the phenotypes are due to loss of neuronal Scamp. Remarkably, neuronal expression of human SCAMP genes rescues selected behavioral phenotypes of the mutants, suggesting the conserved function of SCAMPs across species. The newly developed Drosophila mutants present the first evidence that genetic depletion of SCAMP at the organismal level leads to varied behavioral abnormalities, and the obtained results indicate the importance of membrane dynamics in neuronal functions in vivo.
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Affiliation(s)
- JiaLin C Zheng
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Chook Teng Tham
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Kathleen Keatings
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Steven Fan
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Angela Yen-Chun Liou
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Yuka Numata
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Douglas Allan
- Department of Cellular and Physiological Sciences, University of British Columbia Vancouver, BC, Canada
| | - Masayuki Numata
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
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17
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Neuron-glia interactions through the Heartless FGF receptor signaling pathway mediate morphogenesis of Drosophila astrocytes. Neuron 2014; 83:388-403. [PMID: 25033182 DOI: 10.1016/j.neuron.2014.06.026] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2014] [Indexed: 11/24/2022]
Abstract
Astrocytes are critically important for neuronal circuit assembly and function. Mammalian protoplasmic astrocytes develop a dense ramified meshwork of cellular processes to form intimate contacts with neuronal cell bodies, neurites, and synapses. This close neuron-glia morphological relationship is essential for astrocyte function, but it remains unclear how astrocytes establish their intricate morphology, organize spatial domains, and associate with neurons and synapses in vivo. Here we characterize a Drosophila glial subtype that shows striking morphological and functional similarities to mammalian astrocytes. We demonstrate that the Fibroblast growth factor (FGF) receptor Heartless autonomously controls astrocyte membrane growth, and the FGFs Pyramus and Thisbe direct astrocyte processes to ramify specifically in CNS synaptic regions. We further show that the shape and size of individual astrocytes are dynamically sculpted through inhibitory or competitive astrocyte-astrocyte interactions and Heartless FGF signaling. Our data identify FGF signaling through Heartless as a key regulator of astrocyte morphological elaboration in vivo.
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18
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Perkins AD, Tanentzapf G. An ongoing role for structural sarcomeric components in maintaining Drosophila melanogaster muscle function and structure. PLoS One 2014; 9:e99362. [PMID: 24915196 PMCID: PMC4051695 DOI: 10.1371/journal.pone.0099362] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 05/14/2014] [Indexed: 11/29/2022] Open
Abstract
Animal muscles must maintain their function while bearing substantial mechanical loads. How muscles withstand persistent mechanical strain is presently not well understood. The basic unit of muscle is the sarcomere, which is primarily composed of cytoskeletal proteins. We hypothesized that cytoskeletal protein turnover is required to maintain muscle function. Using the flight muscles of Drosophila melanogaster, we confirmed that the sarcomeric cytoskeleton undergoes turnover throughout adult life. To uncover which cytoskeletal components are required to maintain adult muscle function, we performed an RNAi-mediated knockdown screen targeting the entire fly cytoskeleton and associated proteins. Gene knockdown was restricted to adult flies and muscle function was analyzed with behavioural assays. Here we analyze the results of that screen and characterize the specific muscle maintenance role for several hits. The screen identified 46 genes required for muscle maintenance: 40 of which had no previously known role in this process. Bioinformatic analysis highlighted the structural sarcomeric proteins as a candidate group for further analysis. Detailed confocal and electron microscopic analysis showed that while muscle architecture was maintained after candidate gene knockdown, sarcomere length was disrupted. Specifically, we found that ongoing synthesis and turnover of the key sarcomere structural components Projectin, Myosin and Actin are required to maintain correct sarcomere length and thin filament length. Our results provide in vivo evidence of adult muscle protein turnover and uncover specific functional defects associated with reduced expression of a subset of cytoskeletal proteins in the adult animal.
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Affiliation(s)
- Alexander D. Perkins
- Department of Cellular and Physiological Sciences, University of British Columbia, Life Sciences Institute, Vancouver, British Columbia, Canada
| | - Guy Tanentzapf
- Department of Cellular and Physiological Sciences, University of British Columbia, Life Sciences Institute, Vancouver, British Columbia, Canada
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19
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Drosophila melanogaster as a genetic model system to study neurotransmitter transporters. Neurochem Int 2014; 73:71-88. [PMID: 24704795 DOI: 10.1016/j.neuint.2014.03.015] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 12/30/2022]
Abstract
The model genetic organism Drosophila melanogaster, commonly known as the fruit fly, uses many of the same neurotransmitters as mammals and very similar mechanisms of neurotransmitter storage, release and recycling. This system offers a variety of powerful molecular-genetic methods for the study of transporters, many of which would be difficult in mammalian models. We review here progress made using Drosophila to understand the function and regulation of neurotransmitter transporters and discuss future directions for its use.
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20
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Abstract
Mutations to the SPG4 gene encoding the microtubule-severing protein spastin are the most common cause of hereditary spastic paraplegia. Haploinsufficiency, the prevalent model for the disease, cannot readily explain many of its key aspects, such as its adult onset or its specificity for the corticospinal tracts. Treatment strategies based solely on haploinsufficiency are therefore likely to fail. Toward developing effective therapies, here we investigated potential gain-of-function effects of mutant spastins. The full-length human spastin isoform called M1 or a slightly shorter isoform called M87, both carrying the same pathogenic mutation C448Y, were expressed in three model systems: primary rat cortical neurons, fibroblasts, and transgenic Drosophila. Although both isoforms had ill effects on motor function in transgenic flies and decreased neurite outgrowth from primary cortical neurons, mutant M1 was notably more toxic than mutant M87. The observed phenotypes did not result from dominant-negative effects of mutated spastins. Studies in cultured cells revealed that microtubules can be heavily decorated by mutant M1 but not mutant M87. Microtubule-bound mutant M1 decreased microtubule dynamics, whereas unbound M1 or M87 mutant spastins increased microtubule dynamics. The alterations in microtubule dynamics observed in the presence of mutated spastins are not consistent with haploinsufficiency and are better explained by a gain-of-function mechanism. Our results fortify a model wherein toxicity of mutant spastin proteins, especially mutant M1, contributes to axonal degeneration in the corticospinal tracts. Furthermore, our results provide details on the mechanism of the toxicity that may chart a course toward more effective treatment regimens.
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21
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The systematic identification of cytoskeletal genes required for Drosophila melanogaster muscle maintenance. Sci Data 2014; 1:140002. [PMID: 25977760 PMCID: PMC4365872 DOI: 10.1038/sdata.2014.2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 01/23/2014] [Indexed: 11/18/2022] Open
Abstract
Animal muscles must maintain their function and structure while bearing substantial mechanical loads. How muscles withstand persistent mechanical strain is presently not well understood. Understanding the mechanisms by which tissues maintain their complex architecture is a key goal of cell biology. This dataset represents a systematic screen through the Drosophila melanogaster cytoskeleton to identify genes that are required to maintain tissue, specifically muscle, architecture. Using RNA interference (RNAi), we knocked down 238 genes in Drosophila and assayed for climbing ability with a robust behavioural assay. Here we present the summary of the screen and provide the complete results of the assays. We have uncovered a number of novel hits that would reward further study. The data are easy to use: the raw data are provided to allow researchers to perform their own analysis and analysed results are given indicating whether or not the genes are required for muscle maintenance. This dataset will allow other researchers to identify candidate genes for more detailed study and lead to better understanding of muscle maintenance.
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22
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Berglund EC, Makos MA, Keighron JD, Phan N, Heien ML, Ewing AG. Oral administration of methylphenidate blocks the effect of cocaine on uptake at the Drosophila dopamine transporter. ACS Chem Neurosci 2013; 4:566-74. [PMID: 23402315 DOI: 10.1021/cn3002009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Although our understanding of the actions of cocaine in the brain has improved, an effective drug treatment for cocaine addiction has yet to be found. Methylphenidate binds the dopamine transporter and increases extracellular dopamine levels in mammalian central nervous systems similar to cocaine, but it is thought to elicit fewer addictive and reinforcing effects owing to slower pharmacokinetics for different routes of administration between the drugs. This study utilizes the fruit fly model system to quantify the effects of oral methylphenidate on dopamine uptake during direct cocaine exposure to the fly CNS. The effect of methylphenidate on the dopamine transporter has been explored by measuring the uptake of exogenously applied dopamine. The data suggest that oral consumption of methylphenidate inhibits the Drosophila dopamine transporter and the inhibition is concentration dependent. The peak height increased to 150% of control when cocaine was used to block the dopamine transporter for untreated flies but only to 110% for methylphenidate-treated flies. Thus, the dopamine transporter is mostly inhibited for the methylphenidate-fed flies before the addition of cocaine. The same is true for the rate of the clearance of dopamine measured by amperometry. For untreated flies the rate of clearance changes 40% when the dopamine transporter is inhibited with cocaine, and for treated flies the rate changes only 10%. The results were correlated to the in vivo concentration of methylphenidate determined by CE-MS. Our data suggest that oral consumption of methylphenidate inhibits the Drosophila dopamine transporter for cocaine uptake, and the inhibition is concentration dependent.
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Affiliation(s)
- E. Carina Berglund
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, SE-412 96, Göteborg,
Sweden
| | - Monique A. Makos
- Department of Chemistry, The Pennsylvania State University, University Park,
Pennsylvania 16802, United States
| | - Jacqueline D. Keighron
- Department of Chemistry, Chalmers University of Technology, Kemivägen 10, SE-412 96, Göteborg, Sweden
| | - Nhu Phan
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, SE-412 96, Göteborg,
Sweden
| | - Michael L. Heien
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Boulevard,
Tucson, Arizona 85721, United States
| | - Andrew G. Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, SE-412 96, Göteborg,
Sweden
- Department of Chemistry, Chalmers University of Technology, Kemivägen 10, SE-412 96, Göteborg, Sweden
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23
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Pronovost SM, Beckerle MC, Kadrmas JL. Elevated expression of the integrin-associated protein PINCH suppresses the defects of Drosophila melanogaster muscle hypercontraction mutants. PLoS Genet 2013; 9:e1003406. [PMID: 23555310 PMCID: PMC3610608 DOI: 10.1371/journal.pgen.1003406] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 02/07/2013] [Indexed: 01/05/2023] Open
Abstract
A variety of human diseases arise from mutations that alter muscle contraction. Evolutionary conservation allows genetic studies in Drosophila melanogaster to be used to better understand these myopathies and suggest novel therapeutic strategies. Integrin-mediated adhesion is required to support muscle structure and function, and expression of Integrin adhesive complex (IAC) proteins is modulated to adapt to varying levels of mechanical stress within muscle. Mutations in flapwing (flw), a catalytic subunit of myosin phosphatase, result in non-muscle myosin hyperphosphorylation, as well as muscle hypercontraction, defects in size, motility, muscle attachment, and subsequent larval and pupal lethality. We find that moderately elevated expression of the IAC protein PINCH significantly rescues flw phenotypes. Rescue requires PINCH be bound to its partners, Integrin-linked kinase and Ras suppressor 1. Rescue is not achieved through dephosphorylation of non-muscle myosin, suggesting a mechanism in which elevated PINCH expression strengthens integrin adhesion. In support of this, elevated expression of PINCH rescues an independent muscle hypercontraction mutant in muscle myosin heavy chain, MhcSamba1. By testing a panel of IAC proteins, we show specificity for PINCH expression in the rescue of hypercontraction mutants. These data are consistent with a model in which PINCH is present in limiting quantities within IACs, with increasing PINCH expression reinforcing existing adhesions or allowing for the de novo assembly of new adhesion complexes. Moreover, in myopathies that exhibit hypercontraction, strategic PINCH expression may have therapeutic potential in preserving muscle structure and function. A wide variety of diseases of the muscle are caused by mutations that alter either the actin and myosin contractile machinery or its regulation. One class of mutations of interest results in hypercontraction of the muscle—actin and myosin fibers contract, but cannot efficiently relax. We have used the fruit fly as a model to study these mutations because of the striking similarity of fly and human muscle and because of the many genetic techniques that are available in the fly. Using a genetic approach we identified a protein, PINCH, whose increased expression can rescue the defects observed in hypercontraction mutants. PINCH is a component of integrin adhesion complexes, responsible for anchoring cells in their environment. This suggests that strengthening the anchorage of muscles via PINCH may be an effective strategy to prevent or reduce the muscle damage that occurs in diseases of muscle hypercontraction.
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Affiliation(s)
- Stephen M. Pronovost
- Huntsman Cancer Institute, Departments of Biology and Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Mary C. Beckerle
- Huntsman Cancer Institute, Departments of Biology and Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Julie L. Kadrmas
- Huntsman Cancer Institute, Departments of Biology and Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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24
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Abstract
Animals use gustatory information to assess the suitability of potential food sources and make critical decisions on what to consume. For example, the taste of sugar generally signals a potent dietary source of carbohydrates. However, the intensity of the sensory response to a particular sugar, or "sweetness," is not always a faithful reporter of its nutritional value, and recent evidence suggests that animals can sense the caloric content of food independently of taste. Here, we demonstrate that the vinegar fly Drosophila melanogaster uses both taste and calorie sensing to determine feeding choices, and that the relative contribution of each changes over time. Using the capillary feeder assay, we allowed flies to choose between sources of sugars that varied in their ratio of sweetness to caloric value. We found that flies initially consume sugars according to taste. However, over several hours their preference shifts toward the food source with higher caloric content. This behavioral shift occurs more rapidly following food deprivation and is modulated by cAMP and insulin signaling within neurons. Our results are consistent with the existence of a taste-independent calorie sensor in flies, and suggest that calorie-based reward modifies long-term feeding preferences.
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25
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Phototactic personality in fruit flies and its suppression by serotonin and white. Proc Natl Acad Sci U S A 2012; 109:19834-9. [PMID: 23150588 DOI: 10.1073/pnas.1211988109] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Drosophila typically move toward light (phototax positively) when startled. The various species of Drosophila exhibit some variation in their respective mean phototactic behaviors; however, it is not clear to what extent genetically identical individuals within each species behave idiosyncratically. Such behavioral individuality has indeed been observed in laboratory arthropods; however, the neurobiological factors underlying individual-to-individual behavioral differences are unknown. We developed "FlyVac," a high-throughput device for automatically assessing phototaxis in single animals in parallel. We observed surprising variability within every species and strain tested, including identically reared, isogenic strains. In an extreme example, a domesticated strain of Drosophila simulans harbored both strongly photopositive and strongly photonegative individuals. The particular behavior of an individual fly is not heritable and, because it persists for its lifetime, constitutes a model system for elucidating the molecular mechanisms of personality. Although all strains assayed had greater than expected variation (assuming binomial sampling), some had more than others, implying a genetic basis. Using genetics and pharmacology, we identified the metabolite transporter White and white-dependent serotonin as suppressors of phototactic personality. Because we observed behavioral idiosyncrasy in all experimental groups, we suspect it is present in most behaviors of most animals.
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Tunstall NE, Herr A, de Bruyne M, Warr CG. A screen for genes expressed in the olfactory organs of Drosophila melanogaster identifies genes involved in olfactory behaviour. PLoS One 2012; 7:e35641. [PMID: 22530061 PMCID: PMC3329464 DOI: 10.1371/journal.pone.0035641] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 03/19/2012] [Indexed: 12/20/2022] Open
Abstract
Background For insects the sense of smell and associated olfactory-driven behaviours are essential for survival. Insects detect odorants with families of olfactory receptor proteins that are very different to those of mammals, and there are likely to be other unique genes and genetic pathways involved in the function and development of the insect olfactory system. Methodology/Principal Findings We have performed a genetic screen of a set of 505 Drosophila melanogaster gene trap insertion lines to identify novel genes expressed in the adult olfactory organs. We identified 16 lines with expression in the olfactory organs, many of which exhibited expression of the trapped genes in olfactory receptor neurons. Phenotypic analysis showed that six of the lines have decreased olfactory responses in a behavioural assay, and for one of these we showed that precise excision of the P element reverts the phenotype to wild type, confirming a role for the trapped gene in olfaction. To confirm the identity of the genes trapped in the lines we performed molecular analysis of some of the insertion sites. While for many lines the reported insertion sites were correct, we also demonstrated that for a number of lines the reported location of the element was incorrect, and in three lines there were in fact two pGT element insertions. Conclusions/Significance We identified 16 new genes expressed in the Drosophila olfactory organs, the majority in neurons, and for several of the gene trap lines demonstrated a defect in olfactory-driven behaviour. Further characterisation of these genes and their roles in olfactory system function and development will increase our understanding of how the insect olfactory system has evolved to perform the same essential function to that of mammals, but using very different molecular genetic mechanisms.
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Affiliation(s)
| | | | | | - Coral G. Warr
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- * E-mail:
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Abstract
Epistasis and pleiotropy feature prominently in the genetic architecture of quantitative traits but are difficult to assess in outbred populations. We performed a diallel cross among coisogenic Drosophila P-element mutations associated with hyperaggressive behavior and showed extensive epistatic and pleiotropic effects on aggression, brain morphology, and genome-wide transcript abundance in head tissues. Epistatic interactions were often of greater magnitude than homozygous effects, and the topology of epistatic networks varied among these phenotypes. The transcriptional signatures of homozygous and double heterozygous genotypes derived from the six mutations imply a large mutational target for aggressive behavior and point to evolutionarily conserved genetic mechanisms and neural signaling pathways affecting this universal fitness trait.
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Ali YO, Escala W, Ruan K, Zhai RG. Assaying locomotor, learning, and memory deficits in Drosophila models of neurodegeneration. J Vis Exp 2011:2504. [PMID: 21445036 PMCID: PMC3197301 DOI: 10.3791/2504] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system. Most of these diseases, including Alzheimer's, Parkinson's and Huntington's disease are characterized by age-dependent deterioration in learning and memory functions and movement coordination. Here we use behavioral assays, including the negative geotaxis assay and the aversive phototaxic suppression assay (APS assay), to show that some of the behavior characteristics associated with human neurodegeneration can be recapitulated in flies. In the negative geotaxis assay, the natural tendency of flies to move against gravity when agitated is utilized to study genes or conditions that may hinder locomotor capacities. In the APS assay, the learning and memory functions are tested in positively-phototactic flies trained to associate light with aversive bitter taste and hence avoid this otherwise natural tendency to move toward light. Testing these trained flies 6 hours post-training is used to assess memory functions. Using these assays, the contribution of any genetic or environmental factors toward developing neurodegeneration can be easily studied in flies.
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Affiliation(s)
- Yousuf O Ali
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, USA
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29
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Decourtye A, Devillers J, Aupinel P, Brun F, Bagnis C, Fourrier J, Gauthier M. Honeybee tracking with microchips: a new methodology to measure the effects of pesticides. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:429-437. [PMID: 21267650 DOI: 10.1007/s10646-011-0594-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/04/2011] [Indexed: 05/30/2023]
Abstract
Losses of foraging bees are sometimes attributed to altered flight pattern between a meliferous plant treated with an insecticide and the hive. Only a limited number of studies has investigated the impact of pesticides on homing flight due to the difficulty of measuring the flight time between the food source and the hive. Monitoring the flights of the foraging bees needs their individual identification. The number of bees monitored simultaneously and the time span during which observations can be made limit most of the monitoring techniques. However, techniques of automatic tracking and identification of individuals have the potential to revolutionize the study of the ecotoxicological effects of xenobiotics on the bee behaviors. Radio Frequency Identification (RFID) offer numerous advantages such as an unlimited number of codes, a large number of simultaneous recording, and a quick reading, especially through materials (e.g., wood). The aim of this study was to show how the RFID device can be used to study the effects of pesticides on both the behavioral traits and the lifespan of bees. In this context, we have developed a method under tunnel to automatically record the displacements of foragers individualized with RFID tags and to detect the alteration of the flight pattern between an artificial feeder and the hive. Fipronil was selected as test substance due to the lack of information on the effects of this insecticide on the foraging behavior of free-flying bees. We showed that oral treatment of 0.3 ng of fipronil per bee (LD50/20) reduced the number of foraging trips. The strengths of our approach were briefly discussed.
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Affiliation(s)
- Axel Decourtye
- ACTA, UMT PrADE, UMR 406, Site Agroparc, Avignon, France.
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Oland LA, Gibson NJ, Tolbert LP. Localization of a GABA transporter to glial cells in the developing and adult olfactory pathway of the moth Manduca sexta. J Comp Neurol 2010; 518:815-38. [PMID: 20058309 DOI: 10.1002/cne.22244] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Glial cells have several critical roles in the developing and adult olfactory (antennal) lobe of the moth Manduca sexta. Early in development, glial cells occupy discrete regions of the developing olfactory pathway and processes of gamma-aminobutyric acid (GABA)ergic neurons extend into some of these regions. Because GABA is known to have developmental effects in a variety of systems, we explored the possibility that the glial cells express a GABA transporter that could regulate GABA levels to which olfactory neurons and glial cells are exposed. By using an antibody raised against a characterized high-affinity M. sexta GABA transporter with high sequence homology to known mammalian GABA transporters (Mbungu et al. [1995] Arch. Biochem. Biophys. 318:489-497; Umesh and Gill [2002] J. Comp. Neurol. 448:388-398), we found that the GABA transporter is localized to subsets of centrally derived glial cells during metamorphic adult development. The transporter persists into adulthood in a subset of the neuropil-associated glial cells, but its distribution pattern as determined by light-and electron-microscopic-level immunocytochemistry indicates that it could not serve to regulate GABA concentration in the synaptic cleft. Instead, its role is more likely to regulate extracellular GABA levels within the glomerular neuropil. Expression in the sorting zone glial cells disappears after the period of olfactory receptor axon ingrowth, but may be important during ingrowth if GABA regulates axon growth. Glial cells take up GABA, and that uptake can be blocked by L-2,4-diaminobutyric acid (DABA). This is the first molecular evidence that the central glial cell population in this pathway is heterogeneous.
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Affiliation(s)
- Lynne A Oland
- Department of Neuroscience, University of Arizona, Tucson, Arizona 85721, USA.
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Lin FJ, Pierce MM, Sehgal A, Wu T, Skipper DC, Chabba R. Effect of taurine and caffeine on sleep-wake activity in Drosophila melanogaster. Nat Sci Sleep 2010; 2:221-31. [PMID: 23616711 PMCID: PMC3630960 DOI: 10.2147/nss.s13034] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Caffeine and taurine are two major neuromodulators present in large quantities in many popular energy drinks. We investigated their effects on sleep-wake control in constant darkness using the fruit fly Drosophila as a model system. It has been shown that caffeine, as the most widely used psychostimulant, can boost arousal through the dopamine pathway in the mushroom bodies of flies. Taurine is a GABA receptor agonist, which is inhibitory to neuronal firing. We show here that flies receiving a low dose of caffeine (0.01%) increase locomotor activity by 25%, and decrease total sleep by 15%. Treatment with taurine at 0.1% to 1.5% reduces locomotor activity by 28% to 86%, and shifts it from diurnal to nocturnal. At 0.75%, taurine also increases total sleep by 50%. Our results show that taurine increases sleep, while caffeine, as previously reported, attenuates sleep. Flies treated with both caffeine and taurine exhibit two differential effects which depend upon the ratio of taurine to caffeine. A high taurine:caffeine ratio promotes sleep, while a low ratio of taurine:caffeine inhibits sleep to a greater extent than the equivalent amount of caffeine alone. This intriguing enhancement of caffeine action by low doses of taurine may account for the presence of both compounds in energy-promoting drinks such as Red Bull® and Monster®.
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Affiliation(s)
- Fang Ju Lin
- Department of Biology, Coastal Carolina University, Conway, SC, USA
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Perkins AD, Ellis SJ, Asghari P, Shamsian A, Moore EDW, Tanentzapf G. Integrin-mediated adhesion maintains sarcomeric integrity. Dev Biol 2009; 338:15-27. [PMID: 19879257 DOI: 10.1016/j.ydbio.2009.10.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 10/20/2009] [Accepted: 10/23/2009] [Indexed: 10/24/2022]
Abstract
Integrin-mediated adhesion to the ECM is essential for normal development of animal tissues. During muscle development, integrins provide the structural stability required to construct such a highly tensile, force generating tissue. Mutations that disrupt integrin-mediated adhesion in skeletal muscles give rise to a myopathy in humans and mice. To determine if this is due to defects in formation or defects in maintenance of muscle tissue, we used an inducible, targeted RNAi based approach to disrupt integrin-mediated adhesion in fully formed adult fly muscles. A decrease in integrin-mediated adhesion in adult muscles led to a progressive loss of muscle function due to a failure to maintain normal sarcomeric cytoarchitecture. This defect was due to a gradual, age dependent disorganization of the sarcomeric actin, Z-line, and M-line. Electron microscopic analysis showed that reduction in integrin-mediated adhesion resulted in detachment of actin filaments from the Z-lines, separation of the Z-lines from the membrane, and eventually to disintegration of the Z-lines. Our results show that integrin-mediated adhesion is essential for maintaining sarcomeric integrity and illustrate that the seemingly stable adhesive contacts underlying sarcomeric architecture are inherently dynamic.
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Affiliation(s)
- Alexander D Perkins
- Department of Cellular and Physiological Sciences, University of British Columbia, Life Science Institute, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
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Okada R, Awasaki T, Ito K. Gamma-aminobutyric acid (GABA)-mediated neural connections in the Drosophila antennal lobe. J Comp Neurol 2009; 514:74-91. [PMID: 19260068 DOI: 10.1002/cne.21971] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Inhibitory synaptic connections mediated by gamma-aminobutyric acid (GABA) play important roles in the neural computation of the brain. To obtain a detailed overview of the neural connections mediated by GABA signals, we analyzed the distribution of the cells that produce and receive GABA in the Drosophila adult brain. Relatively small numbers of the cells, which form clusters in several areas of the brain, express the GABA synthesis enzyme Gad1. On the other hand, many cells scattered across the brain express ionotropic GABA(A) receptor subunits (Lcch3 and Rdl) and metabotropic GABA(B) receptor subtypes (GABA-B-R1, -2, and -3). To analyze the expression of these genes in distinct identified cell types, we focused on the antennal lobe, where GABAergic neurons play important roles in odor coding. By combining fluorescent in situ hybridization and immunolabeling against GFP expressed with cell-type-specific GAL4 driver strains, we quantified the percentage of the cells that produce or receive GABA for each cell type. GABA was synthesized in the middle antennocerebral tract (mACT) projection neurons and two types of local neurons. Among them, mACT neurons had few presynaptic sites in the antennal lobe, making the local neurons essentially the sole provider of GABA signals there. On the other hand, not only these local neurons but also all types of projection neurons expressed both ionotropic and metabotropic GABA receptors. Thus, even though inhibitory signals are released from only a few, specific types of local neurons, the signals are read by most of the neurons in the antennal lobe neural circuitry.
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Affiliation(s)
- Ryuichi Okada
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
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Turenius CI, Htut MM, Prodon DA, Ebersole PL, Ngo PT, Lara RN, Wilczynski JL, Stanley BG. GABAA receptors in the lateral hypothalamus as mediators of satiety and body weight regulation. Brain Res 2009; 1262:16-24. [DOI: 10.1016/j.brainres.2009.01.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 01/10/2009] [Accepted: 01/13/2009] [Indexed: 10/21/2022]
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Jordan KW, Carbone MA, Yamamoto A, Morgan TJ, Mackay TFC. Quantitative genomics of locomotor behavior in Drosophila melanogaster. Genome Biol 2008; 8:R172. [PMID: 17708775 PMCID: PMC2375002 DOI: 10.1186/gb-2007-8-8-r172] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 03/26/2007] [Accepted: 08/21/2007] [Indexed: 11/21/2022] Open
Abstract
The locomotor behavior of Drosophila melanogaster was quantified in a large population of inbred lines derived from a single natural population, showing that many pleiotropic genes show correlated transcriptional responses to multiple behaviors. Background Locomotion is an integral component of most animal behaviors, and many human health problems are associated with locomotor deficits. Locomotor behavior is a complex trait, with population variation attributable to many interacting loci with small effects that are sensitive to environmental conditions. However, the genetic basis of this complex behavior is largely uncharacterized. Results We quantified locomotor behavior of Drosophila melanogaster in a large population of inbred lines derived from a single natural population, and derived replicated selection lines with different levels of locomotion. Estimates of broad-sense and narrow-sense heritabilities were 0.52 and 0.16, respectively, indicating substantial non-additive genetic variance for locomotor behavior. We used whole genome expression analysis to identify 1,790 probe sets with different expression levels between the selection lines when pooled across replicates, at a false discovery rate of 0.001. The transcriptional responses to selection for locomotor, aggressive and mating behavior from the same base population were highly overlapping, but the magnitude of the expression differences between selection lines for increased and decreased levels of behavior was uncorrelated. We assessed the locomotor behavior of ten mutations in candidate genes with altered transcript abundance between selection lines, and identified seven novel genes affecting this trait. Conclusion Expression profiling of genetically divergent lines is an effective strategy for identifying genes affecting complex behaviors, and reveals that a large number of pleiotropic genes exhibit correlated transcriptional responses to multiple behaviors.
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Affiliation(s)
- Katherine W Jordan
- Department of Genetics and WM Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695-7614, USA
| | - Mary Anna Carbone
- Department of Genetics and WM Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695-7614, USA
| | - Akihiko Yamamoto
- Department of Genetics and WM Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695-7614, USA
| | - Theodore J Morgan
- Division of Biology, Kansas State University, Ackert Hall, Manhattan, KS 66506, USA
| | - Trudy FC Mackay
- Department of Genetics and WM Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695-7614, USA
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Golombieski RM, Graichen DÂS, Rocha JBTD, Valente VLDS, Loreto ÉLDS. Over-activation of the Drosophila melanogaster hsp83 gene by selenium intoxication. Genet Mol Biol 2008. [DOI: 10.1590/s1415-47572008000100022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Rawls AS, Schultz SA, Mitra RD, Wolff T. Bedraggled, a putative transporter, influences the tissue polarity complex during the R3/R4 fate decision in the Drosophila eye. Genetics 2007; 177:313-28. [PMID: 17890365 PMCID: PMC2013731 DOI: 10.1534/genetics.107.075945] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The tissue polarity pathway is required for the establishment of epithelial polarity in a variety of vertebrate and invertebrate organs. Core tissue polarity proteins act in a dynamically regulated complex to direct the polarization of the Drosophila eye. We report the identification and characterization of bedraggled (bdg), a novel gene that regulates one output of the tissue polarity pathway--the establishment of the R3/R4 photoreceptor fates. bdg encodes a novel, putative transporter protein and interacts genetically with all of the core polarity genes to influence the specification of the R3 and R4 cell fates. Finally, bdg is required for both viability and the initial stages of imaginal disc development.
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Affiliation(s)
- Amy S Rawls
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Muñoz-Alarcón A, Pavlovic M, Wismar J, Schmitt B, Eriksson M, Kylsten P, Dushay MS. Characterization of lamin mutation phenotypes in Drosophila and comparison to human laminopathies. PLoS One 2007; 2:e532. [PMID: 17565385 PMCID: PMC1885830 DOI: 10.1371/journal.pone.0000532] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 05/18/2007] [Indexed: 11/19/2022] Open
Abstract
Lamins are intermediate filament proteins that make up the nuclear lamina, a matrix underlying the nuclear membrane in all metazoan cells that is important for nuclear form and function. Vertebrate A-type lamins are expressed in differentiating cells, while B-type lamins are expressed ubiquitously. Drosophila has two lamin genes that are expressed in A- and B-type patterns, and it is assumed that similarly expressed lamins perform similar functions. However, Drosophila and vertebrate lamins are not orthologous, and their expression patterns evolved independently. It is therefore of interest to examine the effects of mutations in lamin genes. Mutations in the mammalian lamin A/C gene cause a range of diseases, collectively called laminopathies, that include muscular dystrophies and premature aging disorders. We compared the sequences of lamin genes from different species, and we have characterized larval and adult phenotypes in Drosophila bearing mutations in the lam gene that is expressed in the B-type pattern. Larvae move less and show subtle muscle defects, and surviving lam adults are flightless and walk like aged wild-type flies, suggesting that lam phenotypes might result from neuromuscular defects, premature aging, or both. The resemblance of Drosophila lam phenotypes to human laminopathies suggests that some lamin functions may be performed by differently expressed genes in flies and mammals. Such still-unknown functions thus would not be dependent on lamin gene expression pattern, suggesting the presence of other lamin functions that are expression dependent. Our results illustrate a complex interplay between lamin gene expression and function through evolution.
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Affiliation(s)
- Andrés Muñoz-Alarcón
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden
| | - Maja Pavlovic
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden
| | - Jasmine Wismar
- Max-Planck-Institut für Hirnforschung, Abteilung Neurochemie, Frankfurt, Germany
| | - Bertram Schmitt
- Max-Planck-Institut für Hirnforschung, Abteilung Neurochemie, Frankfurt, Germany
| | - Maria Eriksson
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden
| | - Per Kylsten
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
| | - Mitchell S. Dushay
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
- Department of Comparative Physiology, EBC, Uppsala University, Uppsala, Sweden
- * To whom correspondence should be addressed. E-mail:
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Neckameyer WS, Coleman CM, Eadie S, Goodwin SF. Compartmentalization of neuronal and peripheral serotonin synthesis in Drosophila melanogaster. GENES BRAIN AND BEHAVIOR 2007; 6:756-69. [PMID: 17376153 DOI: 10.1111/j.1601-183x.2007.00307.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In Drosophila, one enzyme (Drosophila tryptophan-phenylalanine hydroxylase, DTPHu) hydroxylates both tryptophan to yield 5-hydroxytryptophan, the first step in serotonin synthesis, and phenylalanine, to generate tyrosine. Analysis of the sequenced Drosophila genome identified an additional enzyme with extensive homology to mammalian tryptophan hydroxylase (TPH), which we have termed DTRHn. We have shown that DTRHn can hydroxylate tryptophan in vitro but displays differential activity relative to DTPHu when using tryptophan as a substrate. Recent studies in mice identified the presence of two TPH genes, Tph1 and Tph2, from distinct genetic loci. Tph1 represents the non-neuronal TPH gene, and Tph2 is expressed exclusively in the brain. In this article, we show that DTRHn is neuronal in expression and function and thus represents the Drosophila homologue of Tph2. Using a DTRHn-null mutation, we show that diminished neuronal serotonin affects locomotor, olfactory and feeding behaviors, as well as heart rate. We also show that DTPHu functions in vivo as a phenylalanine hydroxylase in addition to its role as the peripheral TPH in Drosophila, and is critical for non-neuronal developmental events.
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Affiliation(s)
- W S Neckameyer
- Department of Pharmacological and Physiological Science, St Louis, University School of Medicine, MO 63104, USA.
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40
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Sang TK, Chang HY, Lawless GM, Ratnaparkhi A, Mee L, Ackerson LC, Maidment NT, Krantz DE, Jackson GR. A Drosophila model of mutant human parkin-induced toxicity demonstrates selective loss of dopaminergic neurons and dependence on cellular dopamine. J Neurosci 2007; 27:981-92. [PMID: 17267552 PMCID: PMC6673194 DOI: 10.1523/jneurosci.4810-06.2007] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mutations in human parkin have been identified in familial Parkinson's disease and in some sporadic cases. Here, we report that expression of mutant but not wild-type human parkin in Drosophila causes age-dependent, selective degeneration of dopaminergic (DA) neurons accompanied by a progressive motor impairment. Overexpression or knockdown of the Drosophila vesicular monoamine transporter, which regulates cytosolic DA homeostasis, partially rescues or exacerbates, respectively, the degenerative phenotypes caused by mutant human parkin. These results support a model in which the vulnerability of DA neurons to parkin-induced neurotoxicity results from the interaction of mutant parkin with cytoplasmic dopamine.
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Affiliation(s)
- Tzu-Kang Sang
- Neurogenetics and Movement Disorders Programs, Department of Neurology, and
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Taiwan, Republic of China, and
| | | | - George M. Lawless
- Neurogenetics and Movement Disorders Programs, Department of Neurology, and
| | | | - Lisa Mee
- Neurogenetics and Movement Disorders Programs, Department of Neurology, and
| | | | - Nigel T. Maidment
- Department of Psychiatry and Biobehavioral Sciences
- Brain Research Institute
- Hatos Center for Neuropharmacology, and
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095
| | - David E. Krantz
- Department of Psychiatry and Biobehavioral Sciences
- Brain Research Institute
- Hatos Center for Neuropharmacology, and
| | - George R. Jackson
- Neurogenetics and Movement Disorders Programs, Department of Neurology, and
- Brain Research Institute
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095
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Nichols CD. Drosophila melanogaster neurobiology, neuropharmacology, and how the fly can inform central nervous system drug discovery. Pharmacol Ther 2006; 112:677-700. [PMID: 16935347 DOI: 10.1016/j.pharmthera.2006.05.012] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 05/24/2006] [Indexed: 01/25/2023]
Abstract
Central nervous system (CNS) drug discovery in the post-genomic era is rapidly evolving. Older empirical methods are giving way to newer technologies that include bioinformatics, structural biology, genetics, and modern computational approaches. In the search for new medical therapies, and in particular treatments for disorders of the central nervous system, there has been increasing recognition that identification of a single biological target is unlikely to be a recipe for success; a broad perspective is required. Systems biology is one such approach, and has been increasingly recognized as a very important area of research, as it places specific molecular targets within a context of overall biochemical action. Understanding the complex interactions between the components within a given biological system that lead to modifications in output, such as changes in behavior or development, may be important avenues of discovery to identify new therapies. One avenue to drug discovery that holds tremendous potential is the use of model genetic organisms such as the fruit fly, Drosophila melanogaster. The similarity between mode of drug action, behavior, and gene response in D. melanogaster and mammalian systems, combined with the power of genetics, have recently made the fly a very attractive system to study fundamental neuropharmacological processes relevant to human diseases. The promise that the use of model organisms such as the fly offers is speed, high throughput, and dramatically reduced overall costs that together should result in an enhanced rate of discovery.
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Affiliation(s)
- Charles D Nichols
- Department of Pharmacology and Experimental Therapeutics, LSU Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA.
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Jordan KW, Morgan TJ, Mackay TFC. Quantitative trait loci for locomotor behavior in Drosophila melanogaster. Genetics 2006; 174:271-84. [PMID: 16783013 PMCID: PMC1569784 DOI: 10.1534/genetics.106.058099] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Locomotion is an integral component of most animal behaviors and many human diseases and disorders are associated with locomotor deficits, but little is known about the genetic basis of natural variation in locomotor behavior. Locomotion is a complex trait, with variation attributable to the joint segregation of multiple interacting quantitative trait loci (QTL), with effects that are sensitive to the environment. We assessed variation in a component of locomotor behavior (locomotor reactivity) in a population of 98 recombinant inbred lines of Drosophila melanogaster and mapped four QTL affecting locomotor reactivity by linkage to polymorphic roo transposable element insertion sites. We used complementation tests of deficiencies to fine map these QTL to 12 chromosomal regions and complementation tests of mutations to identify 13 positional candidate genes affecting locomotor reactivity, including Dopa decarboxylase (Ddc), which catalyzes the final step in the synthesis of serotonin and dopamine. Linkage disequilibrium mapping in a population of 164 second chromosome substitution lines derived from a single natural population showed that polymorphisms at Ddc were associated with naturally occurring genetic variation in locomotor behavior. These data implicate variation in the synthesis of bioamines as a factor contributing to natural variation in locomotor reactivity.
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Affiliation(s)
- Katherine W Jordan
- Department of Genetics and W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina 27695-7614, USA.
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Hyun S, Lee Y, Hong ST, Bang S, Paik D, Kang J, Shin J, Lee J, Jeon K, Hwang S, Bae E, Kim J. Drosophila GPCR Han is a receptor for the circadian clock neuropeptide PDF. Neuron 2006; 48:267-78. [PMID: 16242407 DOI: 10.1016/j.neuron.2005.08.025] [Citation(s) in RCA: 219] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Revised: 06/16/2005] [Accepted: 08/19/2005] [Indexed: 11/22/2022]
Abstract
The pigment-dispersing factor (PDF) is a neuropeptide controlling circadian behavioral rhythms in Drosophila, but its receptor is not yet known. From a large-scale temperature preference behavior screen in Drosophila, we isolated a P insertion mutant that preferred different temperatures during the day and night. This mutation, which we named han, reduced the transcript level of CG13758. We found that Han was expressed specifically in 13 pairs of circadian clock neurons in the adult brain. han null flies showed arrhythmic circadian behavior in constant darkness. The behavioral characteristics of han null mutants were similar to those of pdf null mutants. We also found that PDF binds specifically to S2 cells expressing Han, which results in the elevation of cAMP synthesis. Therefore, we herein propose that Han is a PDF receptor regulating circadian behavioral rhythm through coordination of activities of clock neurons.
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Affiliation(s)
- Seogang Hyun
- Department of Biological Sciences, Korea Advanced Institute of Science & Technology, 373-1 Guseong-Dong, Yuseong-Gu, Daejeon 305-701, Korea
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El Hassani AK, Dacher M, Gauthier M, Armengaud C. Effects of sublethal doses of fipronil on the behavior of the honeybee (Apis mellifera). Pharmacol Biochem Behav 2005; 82:30-9. [PMID: 16102801 DOI: 10.1016/j.pbb.2005.07.008] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Revised: 07/12/2005] [Accepted: 07/13/2005] [Indexed: 10/25/2022]
Abstract
Fipronil is a phenylpyrazole insecticide introduced for pest control, but it can also affect non-target insects such as honeybees. In insects, fipronil is known to block GABA receptors and to inhibit ionotropic glutamate-gated chloride channels, but the behavioral effects of low doses are not yet fully understood. We have studied the effect of sublethal doses of fipronil on the behavior of the honeybee (Apis mellifera) under controlled laboratory conditions. The drug was either administered orally or applied topically on the thorax. A significant reduction of sucrose sensitivity was observed for the dose of 1 ng/bee 1 h after a thoracic application. No significant effect on sucrose sensitivity was obtained with acute oral treatment. A lower dose of fipronil (0.5 ng/bee applied topically) impaired the olfactory learning of the honeybees. By contrast, locomotor activity was not affected. Our results suggest a particular vulnerability of the olfactory memory processes and sucrose perception to sublethal doses of fipronil in the honeybee.
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Affiliation(s)
- Abdessalam Kacimi El Hassani
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III-CNRS UMR 5169, 118 Route de Narbonne, 31062 Toulouse Cedex 04, France
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45
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Morrow G, Samson M, Michaud S, Tanguay RM. Overexpression of the small mitochondrial Hsp22 extends Drosophila life span and increases resistance to oxidative stress. FASEB J 2004; 18:598-9. [PMID: 14734639 DOI: 10.1096/fj.03-0860fje] [Citation(s) in RCA: 267] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Heat shock proteins (Hsp) are involved in protein folding, transport and stress resistance. Studies reporting an increased mRNA level of hsp genes in aged Drosophila suggest that expression of Hsp might be beneficial in preventing damages induced by aging. Because oxidative damage is often observed in aged organisms and mitochondria are sensitive to reactive oxygen species, we tested the hypothesis that increased levels of a small Hsp localized in mitochondria, Hsp22 of Drosophila melanogaster, could protect mitochondrial proteins and influence the aging process. We demonstrate that a ubiquitous or a targeted expression of Hsp22 within motorneurons increases the mean life span by more than 30%. Hsp22 shows beneficial effects on early-aging events since the premortality phase displays the same increase as the mean lifespan. Moreover, flies expressing Hsp22 in their motorneurons maintain their locomotor activity longer as assessed by a negative geotaxis assay. The motorneurons-targeted expression of Hsp22 also significantly increases flies' resistance to oxidative injuries induced by paraquat (up to 35%) and thermal stress (39% at 30 degrees C and 23% at 37 degrees C). These observations establish Hsp22 as a key player in cell-protection mechanisms against oxidative injuries and aging in Drosophila and corroborate the pivotal role of mitochondria in the process of aging.
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Affiliation(s)
- Geneviève Morrow
- Laboratory of Cell and Developmental Genetics, CREFSIP and Department Medicine, Université Laval, Ste-Foy, Québec, Canada
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Reynolds ER, Stauffer EA, Feeney L, Rojahn E, Jacobs B, McKeever C. Treatment with the antiepileptic drugs phenytoin and gabapentin ameliorates seizure and paralysis ofDrosophila bang-sensitive mutants. ACTA ACUST UNITED AC 2004; 58:503-13. [PMID: 14978727 DOI: 10.1002/neu.10297] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Drosophila bang-sensitive (bs) mutants exhibit a stereotypic seizure and paralysis following exposure to mechanical shock. In a physiological preparation, seizures and failures corresponding to the defective behavior are observed in response to high frequency stimulation. The amplitude of the stimulus necessary to produce bs behavior, or seizure threshold, varies with bs mutant and its gene dosage. In many respects, the bs defects are similar to those observed in mammalian seizure disorders. Antiepileptic drugs (AEDs) were administered by feeding to easily shocked(2) (eas(2)), a representative bs mutant. The mean recovery times of treated flies were examined in comparison to control cultures. Some of the drugs administered, including carbamazeprine, ethosuximide, and vigabactrin, had little or no effect on the bs behavior of eas(2). Gabapentin, however, showed a reduction in mean recovery time with chronic drug exposure. Phenytoin also had a significant effect on the bs behavior of treated flies. There was a reduction of both mean recovery time and the percentage of flies that displayed bang-sensitive behavior with both acute and chronic treatment. The adult giant fiber preparation was used to examine the effects of phenytoin physiologically. Treated eas(2) flies showed changes in their response to normal stimulation as well as alterations in seizure threshold in response to high frequency stimulation. Gabapentin was also effective against two other bs mutants, bangsenseless(1) and slamdance(iso7.8), at strain-specific concentrations, while phenytoin also reduced bang-sensitive behaviors in bangsenseless(1) in a dose dependent manner. AEDs, therefore, can be used to dissect aspects of bs behavior and this model may be useful in understanding the underlying basis of seizure disorders.
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Affiliation(s)
- Elaine R Reynolds
- Department of Biology, Lafayette College, Easton, Pennsylvania 18042, USA
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Leal SM, Kumar N, Neckameyer WS. GABAergic modulation of motor-driven behaviors in juvenileDrosophila and evidence for a nonbehavioral role for GABA transport. ACTA ACUST UNITED AC 2004; 61:189-208. [PMID: 15389689 DOI: 10.1002/neu.20061] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have identified specific GABAergic-modulated behaviors in the juvenile stage of the fruit fly, Drosophila melanogaster via systemic treatment of second instar larvae with the potent GABA transport inhibitor DL-2,4-diaminobutyric acid (DABA). DABA significantly inhibited motor-controlled body wall and mouth hook contractions and impaired rollover activity and contractile responses to touch stimulation. The perturbations in locomotion and rollover activity were reminiscent of corresponding DABA-induced deficits in locomotion and the righting reflex observed in adult flies. The effects were specific to these motor-controlled behaviors, because DABA-treated larvae responded normally in olfaction and phototaxis assays. Recovery of these behaviors was achieved by cotreatment with the vertebrate GABA(A) receptor antagonist picrotoxin. Pharmacological studies performed in vitro with plasma membrane vesicles isolated from second instar larval tissues verified the presence of high-affinity, saturable GABA uptake mechanisms. GABA uptake was also detected in plasma membrane vesicles isolated from behaviorally quiescent stages. Competitive inhibition studies of [3H]-GABA uptake into plasma membrane vesicles from larval and pupal tissues with either unlabeled GABA or the transport inhibitors DABA, nipecotic acid, or valproic acid, revealed differences in affinities. GABAergic-modulation of motor behaviors is thus conserved between the larval and adult stages of Drosophila, as well as in mammals and other vertebrate species. The pharmacological studies reveal shared conservation of GABA transport mechanisms between Drosophila and mammals, and implicate the involvement of GABA and GABA transporters in regulating physiological processes distinct from neurotransmission during behaviorally quiescent stages of development.
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Affiliation(s)
- Sandra M Leal
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 S. Grand Blvd., St. Louis, Missouri 63103, USA
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Ribeiro JMC. A catalogue of Anopheles gambiae transcripts significantly more or less expressed following a blood meal. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2003; 33:865-882. [PMID: 12915178 DOI: 10.1016/s0965-1748(03)00080-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The recent assembly of the Anopheles gambiae genome included the sequencing of ~80,000 EST from blood fed (BF) and non-blood fed (NBF) adult female mosquitoes to help find the exons and introns in the mosquito genome. These two EST libraries provided an insight into the differential gene expression resulting from the metabolically intense task of converting the massive blood meal into eggs. Previously, 168 genes have been identified to be either significantly more or significantly less transcribed after the blood meal [Science 298 (2002) 129]. Presently, 435 transcripts are described; these are grouped in supplemental tables by probable function to facilitate public access to these data and to help in designing postgenome experiments in the biology of Anopheles gambiae. The electronic tables and supplemental material are available at http://www.ncbi.nlm.nih.gov/projects/Mosquito/Ag-ESTs.
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Affiliation(s)
- José M C Ribeiro
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0425, USA.
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49
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GABA receptors containing Rdl subunits mediate fast inhibitory synaptic transmission in Drosophila neurons. J Neurosci 2003. [PMID: 12805302 DOI: 10.1523/jneurosci.23-11-04625.2003] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
GABAergic inhibition in Drosophila, as in other insects and mammals, is important for regulation of activity in the CNS. However, the functional properties of synaptic GABA receptors in Drosophila have not been described. Here, we report that spontaneous GABAergic postsynaptic currents (sPSCs) in cultured embryonic Drosophila neurons are mediated by picrotoxin-sensitive chloride-conducting receptors. A rapid increase in spontaneous firing in response to bath application of picrotoxin demonstrates that these GABA receptors mediate inhibition in the neuronal networks formed in culture. Many of the spontaneous GABAergic synaptic currents are sodium action potential independent [miniature IPSCs (mIPSCs)] but are regulated by external calcium levels. The large variation in mIPSC frequency, amplitude, and kinetics properties between neurons suggests heterogeneity in GABA receptor number, location, and/or subtype. A decrease in the mean mIPSC decay time constant between 2 and 5 d, in the absence of a correlated change in rise time, demonstrates that the functional properties of the synaptic GABA receptors are regulated during maturation in vitro. Finally, neurons from the GABA receptor subunit mutant Rdl exhibit reduced sensitivity to picrotoxin blockade of the mIPSCs and resistance to picrotoxin-induced increases in spontaneous firing frequency. This demonstrates that Rdl containing GABA receptors play a direct role in mediating synaptic inhibition in Drosophila neural circuits formed in culture.
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50
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Manev H, Dimitrijevic N, Dzitoyeva S. Techniques: fruit flies as models for neuropharmacological research. Trends Pharmacol Sci 2003; 24:41-3. [PMID: 12498730 DOI: 10.1016/s0165-6147(02)00004-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An unlikely animal model is gaining popularity in neuropharmacological research: the 2-mm fruit fly (Drosophila melanogaster). Drugs have been administered to adult flies in their food and, more recently, via gasses and injections. Pharmacological tools have introduced behavioral alterations in Drosophila reminiscent of human behavior, rescued flies from gene-alteration-triggered neuropathologies, and triggered gene silencing. Combined, these methods hold promise for significant neuropharmacological advancement.
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Affiliation(s)
- Hari Manev
- Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, 1601 West Taylor Street, MC912, Chicago, IL 60612, USA.
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