1
|
Xu C, Wu X, Qiu J, Ye J, Lin Q, Deng J, Zeng Y, Wang W, Zhang H, Zheng H. Genome-wide identification of gap junction gene family and their expression profiles under low temperature stress in noble scallop Chlamys nobilis. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2024; 52:101310. [PMID: 39137603 DOI: 10.1016/j.cbd.2024.101310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/13/2024] [Accepted: 08/08/2024] [Indexed: 08/15/2024]
Abstract
Gap junctions, formed by gap junction proteins (GJ), play crucial roles in cell signaling and immune responses. The structure and function of the GJ from vertebrates (called connexins) have been extensively studied. However, little is known about the proteins forming gap junctions in invertebrates (called innexins). In this study, 14 GJ genes of Chlamys nobilis were identified. GJ proteins are mainly distributed on the plasma membrane, and all proteins are hydrophilic Phylogenetic tree analysis showed that the GJ proteins in C. nobilis were distantly related to those in vertebrates but closely related to those in invertebrates. Conserved motifs analysis of these GJ proteins in C. nobilis identified to have 10 conserved motifs, similar to gap junction proteins in other bivalves. Moreover, expression profiles of CnGJ genes under chronic and acute low temperature stress were also investigated. Results showed that chronic low temperature stress had a significant effect on the expression levels of CnGJ genes, and the expression profiles of CnGJ genes showed significantly variation under acute low temperature stress. All these results indicated that CnGJ genes play important roles in environmental adaptation in scallops. The present study initially elucidated the function of gap junction genes in noble scallop C. nobilis, which provides new insights into the GJ genes in mollusks and will help us better understand their roles in environmental stress in scallops.
Collapse
Affiliation(s)
- Changping Xu
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China
| | - Xuanbing Wu
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China
| | - Jiale Qiu
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China
| | - Jianming Ye
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China
| | - Qing Lin
- Shantou Fruit Tree and Aquatic Technology Promotion Station, Shantou 515063, China
| | - Jingwen Deng
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China
| | - Yetao Zeng
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China
| | - Weili Wang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China
| | - Hongkuan Zhang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China.
| | - Huaiping Zheng
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Research Center of Engineering Technology for Subtropical Mariculture of Guangdong Province, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China.
| |
Collapse
|
2
|
Ohnishi K, Sokabe T, Miura T, Tominaga M, Ohta A, Kuhara A. G protein-coupled receptor-based thermosensation determines temperature acclimatization of Caenorhabditis elegans. Nat Commun 2024; 15:1660. [PMID: 38396085 PMCID: PMC10891075 DOI: 10.1038/s41467-024-46042-z] [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: 03/30/2023] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Animals must sense and acclimatize to environmental temperatures for survival, yet their thermosensing mechanisms other than transient receptor potential (TRP) channels remain poorly understood. We identify a trimeric G protein-coupled receptor (GPCR), SRH-40, which confers thermosensitivity in sensory neurons regulating temperature acclimatization in Caenorhabditis elegans. Systematic knockdown of 1000 GPCRs by RNAi reveals GPCRs involved in temperature acclimatization, among which srh-40 is highly expressed in the ADL sensory neuron, a temperature-responsive chemosensory neuron, where TRP channels act as accessorial thermoreceptors. In vivo Ca2+ imaging demonstrates that an srh-40 mutation reduced the temperature sensitivity of ADL, resulting in supranormal temperature acclimatization. Ectopically expressing SRH-40 in a non-warmth-sensing gustatory neuron confers temperature responses. Moreover, temperature-dependent SRH-40 activation is reconstituted in Drosophila S2R+ cells. Overall, SRH-40 may be involved in thermosensory signaling underlying temperature acclimatization. We propose a dual thermosensing machinery through a GPCR and TRP channels in a single sensory neuron.
Collapse
Affiliation(s)
- Kohei Ohnishi
- Graduate school of Natural Science, Konan University, Kobe, Hyogo, 658-8501, Japan
- Faculty of Science and Engineering, Konan University, Kobe, Hyogo, 658-8501, Japan
- Institute for Integrative Neurobiology, Konan University, Kobe, Hyogo, 658-8501, Japan
- Physiology and Biophysics, Graduate School of Biomedical and Health Sciences (Medical), Hiroshima University, Hiroshima, 734-8553, Japan
| | - Takaaki Sokabe
- Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan.
- Thermal Biology Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8787, Japan.
- Department of Physiological Sciences, SOKENDAI, Okazaki, Aichi, 444-8787, Japan.
- AMED-PRIME, Japan Agency for Medical Research and Development, Tokyo, 100-0004, Japan.
| | - Toru Miura
- Faculty of Science and Engineering, Konan University, Kobe, Hyogo, 658-8501, Japan
- Institute for Integrative Neurobiology, Konan University, Kobe, Hyogo, 658-8501, Japan
| | - Makoto Tominaga
- Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan
- Thermal Biology Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8787, Japan
- Department of Physiological Sciences, SOKENDAI, Okazaki, Aichi, 444-8787, Japan
| | - Akane Ohta
- Graduate school of Natural Science, Konan University, Kobe, Hyogo, 658-8501, Japan.
- Faculty of Science and Engineering, Konan University, Kobe, Hyogo, 658-8501, Japan.
- Institute for Integrative Neurobiology, Konan University, Kobe, Hyogo, 658-8501, Japan.
| | - Atsushi Kuhara
- Graduate school of Natural Science, Konan University, Kobe, Hyogo, 658-8501, Japan.
- Faculty of Science and Engineering, Konan University, Kobe, Hyogo, 658-8501, Japan.
- Institute for Integrative Neurobiology, Konan University, Kobe, Hyogo, 658-8501, Japan.
- AMED-PRIME, Japan Agency for Medical Research and Development, Tokyo, 100-0004, Japan.
| |
Collapse
|
3
|
Abstract
Foraging animals optimize feeding decisions by adjusting both common and rare behavioral patterns. Here, we characterize the relationship between an animal's arousal state and a rare decision to leave a patch of bacterial food. Using long-term tracking and behavioral state classification, we find that food leaving decisions in Caenorhabditis elegans are coupled to arousal states across multiple timescales. Leaving emerges probabilistically over minutes from the high arousal roaming state, but is suppressed during the low arousal dwelling state. Immediately before leaving, animals have a brief acceleration in speed that appears as a characteristic signature of this behavioral motif. Neuromodulatory mutants and optogenetic manipulations that increase roaming have a coupled increase in leaving rates, and similarly acute manipulations that inhibit feeding induce both roaming and leaving. By contrast, inactivating a set of chemosensory neurons that depend on the cGMP-gated transduction channel TAX-4 uncouples roaming and leaving dynamics. In addition, tax-4-expressing sensory neurons promote lawn-leaving behaviors that are elicited by feeding inhibition. Our results indicate that sensory neurons responsive to both internal and external cues play an integrative role in arousal and foraging decisions.
Collapse
Affiliation(s)
- Elias Scheer
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller UniversityNew YorkUnited States
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller UniversityNew YorkUnited States
| |
Collapse
|
4
|
Nava S, Palma W, Wan X, Oh JY, Gharib S, Wang H, Revanna JS, Tan M, Zhang M, Liu J, Chen CH, Lee JS, Perry B, Sternberg PW. A cGAL-UAS bipartite expression toolkit for Caenorhabditis elegans sensory neurons. Proc Natl Acad Sci U S A 2023; 120:e2221680120. [PMID: 38096407 PMCID: PMC10743456 DOI: 10.1073/pnas.2221680120] [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: 12/26/2022] [Accepted: 10/05/2023] [Indexed: 12/18/2023] Open
Abstract
Animals integrate sensory information from the environment and display various behaviors in response to external stimuli. In Caenorhabditis elegans hermaphrodites, 33 types of sensory neurons are responsible for chemosensation, olfaction, and mechanosensation. However, the functional roles of all sensory neurons have not been systematically studied due to the lack of facile genetic accessibility. A bipartite cGAL-UAS system has been previously developed to study tissue- or cell-specific functions in C. elegans. Here, we report a toolkit of new cGAL drivers that can facilitate the analysis of a vast majority of the 60 sensory neurons in C. elegans hermaphrodites. We generated 37 sensory neuronal cGAL drivers that drive cGAL expression by cell-specific regulatory sequences or intersection of two distinct regulatory regions with overlapping expression (split cGAL). Most cGAL-drivers exhibit expression in single types of cells. We also constructed 28 UAS effectors that allow expression of proteins to perturb or interrogate sensory neurons of choice. This cGAL-UAS sensory neuron toolkit provides a genetic platform to systematically study the functions of C. elegans sensory neurons.
Collapse
Affiliation(s)
- Stephanie Nava
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Wilber Palma
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Xuan Wan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Jun Young Oh
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Shahla Gharib
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Han Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Jasmin S. Revanna
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Minyi Tan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Mark Zhang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Jonathan Liu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Chun-Hao Chen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - James S. Lee
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Barbara Perry
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Paul W. Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| |
Collapse
|
5
|
Cowen MH, Reddy KC, Chalasani SH, Hart MP. Conserved autism-associated genes tune social feeding behavior in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570116. [PMID: 38106124 PMCID: PMC10723370 DOI: 10.1101/2023.12.05.570116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Animal foraging is an essential and evolutionarily conserved behavior that occurs in social and solitary contexts, but the underlying molecular pathways are not well defined. We discover that conserved autism-associated genes (NRXN1(nrx-1), NLGN3(nlg-1), GRIA1,2,3(glr-1), GRIA2(glr-2), and GLRA2,GABRA3(avr-15)) regulate aggregate feeding in C. elegans, a simple social behavior. NRX-1 functions in chemosensory neurons (ADL and ASH) independently of its postsynaptic partner NLG-1 to regulate social feeding. Glutamate from these neurons is also crucial for aggregate feeding, acting independently of NRX-1 and NLG-1. Compared to solitary counterparts, social animals show faster presynaptic release and more presynaptic release sites in ASH neurons, with only the latter requiring nrx-1. Disruption of these distinct signaling components additively converts behavior from social to solitary. Aggregation induced by circuit activation is also dependent on nrx-1. Collectively, we find that aggregate feeding is tuned by conserved autism-associated genes through complementary synaptic mechanisms, revealing molecular principles driving social feeding.
Collapse
Affiliation(s)
- Mara H. Cowen
- Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA
- Autism Spectrum Program of Excellence, Perelman School of Medicine, Philadelphia, PA
| | - Kirthi C. Reddy
- Molecular Neurobiology Laboratory, Salk Institute, La Jolla, CA
| | | | - Michael P. Hart
- Department of Genetics, University of Pennsylvania, Philadelphia, PA
- Autism Spectrum Program of Excellence, Perelman School of Medicine, Philadelphia, PA
| |
Collapse
|
6
|
Hiramatsu F, Lightfoot JW. Kin-recognition and predation shape collective behaviors in the cannibalistic nematode Pristionchus pacificus. PLoS Genet 2023; 19:e1011056. [PMID: 38096160 PMCID: PMC10721034 DOI: 10.1371/journal.pgen.1011056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/08/2023] [Indexed: 12/17/2023] Open
Abstract
Kin-recognition is observed across diverse species forming an important behavioral adaptation influencing organismal interactions. In many species, the molecular mechanisms involved are difficult to characterize, but in the nematode Pristionchus pacificus molecular components regulating its kin-recognition system have been identified. These determine its predatory behaviors towards other con-specifics which prevents the killing and cannibalization of kin. Importantly, their impact on other interactions including collective behaviors is unknown. Here, we explored a high altitude adapted clade of this species which aggregates abundantly under laboratory conditions, to investigate the influence of the kin-recognition system on their group behaviours. By utilizing pairwise aggregation assays between distinct strains of P. pacificus with differing degrees of genetic relatedness, we observe aggregation between kin but not distantly related strains. In assays between distantly related strains, the aggregation ratio is frequently reduced. Furthermore, abolishing predation behaviors through CRISPR/Cas9 induced mutations in Ppa-nhr-40 result in rival strains successfully aggregating together. Finally, as Caenorhabditis elegans are found naturally occurring with P. pacificus, we also explored aggregation events between these species. Here, aggregates were dominated by P. pacificus with the presence of only a small number of predators proving sufficient to disrupt C. elegans aggregation dynamics. Thus, aggregating strains of P. pacificus preferentially group with kin, revealing competition and nepotism as previously unknown components influencing collective behaviors in nematodes.
Collapse
Affiliation(s)
- Fumie Hiramatsu
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior–caesar, Bonn, Germany
- International Max Planck Research School for Brain and Behavior, Bonn, Germany
| | - James W. Lightfoot
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior–caesar, Bonn, Germany
| |
Collapse
|
7
|
Zhang X, Wang Y, Cai Z, Wan Z, Aihemaiti Y, Tu H. A gonadal gap junction INX-14/Notch GLP-1 signaling axis suppresses gut defense through an intestinal lysosome pathway. Front Immunol 2023; 14:1249436. [PMID: 37928537 PMCID: PMC10620905 DOI: 10.3389/fimmu.2023.1249436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/03/2023] [Indexed: 11/07/2023] Open
Abstract
Gap junctions mediate intercellular communications across cellular networks in the nervous and immune systems. Yet their roles in intestinal innate immunity are poorly understood. Here, we show that the gap junction/innexin subunit inx-14 acts in the C. elegans gonad to attenuate intestinal defenses to Pseudomonas aeruginosa PA14 infection through the PMK-1/p38 pathway. RNA-Seq analyses revealed that germline-specific inx-14 RNAi downregulated Notch/GLP-1 signaling, while lysosome and PMK-1/p38 pathways were upregulated. Consistently, disruption of inx-14 or glp-1 in the germline enhanced resistance to PA14 infection and upregulated lysosome and PMK-1/p38 activity. We show that lysosome signaling functions downstream of the INX-14/GLP-1 signaling axis and upstream of PMK-1/p38 pathway to facilitate intestinal defense. Our findings expand the understanding of the links between the reproductive system and intestinal defense, which may be evolutionarily conserved in higher organism.
Collapse
Affiliation(s)
| | | | | | | | | | - Haijun Tu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
| |
Collapse
|
8
|
Almoril-Porras A, Calvo AC, Niu L, Beagan J, Hawk JD, Aljobeh A, Wisdom EM, Ren I, Díaz-García M, Wang ZW, Colón-Ramos DA. Specific configurations of electrical synapses filter sensory information to drive choices in behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551556. [PMID: 37577611 PMCID: PMC10418224 DOI: 10.1101/2023.08.01.551556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Synaptic configurations in precisely wired circuits underpin how sensory information is processed by the nervous system, and the emerging animal behavior. This is best understood for chemical synapses, but far less is known about how electrical synaptic configurations modulate, in vivo and in specific neurons, sensory information processing and context-specific behaviors. We discovered that INX-1, a gap junction protein that forms electrical synapses, is required to deploy context-specific behavioral strategies during C. elegans thermotaxis behavior. INX-1 couples two bilaterally symmetric interneurons, and this configuration is required for the integration of sensory information during migration of animals across temperature gradients. In inx-1 mutants, uncoupled interneurons display increased excitability and responses to subthreshold temperature stimuli, resulting in abnormally longer run durations and context-irrelevant tracking of isotherms. Our study uncovers a conserved configuration of electrical synapses that, by increasing neuronal capacitance, enables differential processing of sensory information and the deployment of context-specific behavioral strategies.
Collapse
Affiliation(s)
- Agustin Almoril-Porras
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ana C. Calvo
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Longgang Niu
- Department of Neuroscience, University of Connecticut Health Center; Farmington, CT 06030, USA
| | - Jonathan Beagan
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Josh D. Hawk
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ahmad Aljobeh
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Elias M. Wisdom
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ivy Ren
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Malcom Díaz-García
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center; Farmington, CT 06030, USA
| | - Daniel A. Colón-Ramos
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
- Wu Tsai Institute, Yale University; New Haven, CT 06510, USA
- Marine Biological Laboratory; Woods Hole, MA, USA
- Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico; San Juan 00901, Puerto Rico
| |
Collapse
|
9
|
Tamagno WA, Alves C, Pompermaier A, Dos Santos HC, Barcellos LJG. Effects of used and under-used doses of Transfluthrin-based insecticide on Caenorhabditis elegans metabolism. Toxicol Appl Pharmacol 2023; 461:116410. [PMID: 36738974 DOI: 10.1016/j.taap.2023.116410] [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: 11/08/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
Different classes of insecticide compounds have been employed to control insects and mosquitoes; Pyrethroids are one of the most common used in both urban and rural household environments. This study investigated the effects of exposure of two doses of commercial transfluthrin-based insecticide (T-BI) on behavior (body bends, pharyngeal pumping rate, and feeding attributes) and biochemical biomarkers (AChE, PolyQ40 aggregations, HSP, antioxidative SOD, CTL, and GST) following three different protocols (transgenerational, neonatal, and lifespan) in Caenorhabditis elegans model system. The relative calculated dose (RCD) and relative calculated half dose (RCHD) of T-BI were compared with those of the control (water). T-BI reduced the health span of worms treated during their whole life and changed biochemical and behavioral patterns due to progenitors' uterine (transgenerational) and neonatal exposures. It was inferred that the effects of T-BI are transgenerational and persistent and can be harmful to non-target species, including humans. In addition, our findings highlight that T-BI contact by progenitors accelerates the establishment of Huntington's disease and causes a cholinergic outbreak in offspring adulthood.
Collapse
Affiliation(s)
- Wagner Antonio Tamagno
- Graduate Program in Pharmacology, Universidade Federal de Santa Maria, Av. Roraima, 1000, Cidade Universitária, Camobi, Santa Maria, RS 97105-900, Brazil; Biochemistry and Molecular Biology Laboratory Rosilene Rodrigues Kaizer, Federal Institute of Education, Science and Technology of Rio Grande do Sul, Campus Sertão, ERS 135, Km 25, Eng, Englert, RS, 99170-000, Brazil.
| | - Carla Alves
- Biochemistry and Molecular Biology Laboratory Rosilene Rodrigues Kaizer, Federal Institute of Education, Science and Technology of Rio Grande do Sul, Campus Sertão, ERS 135, Km 25, Eng, Englert, RS, 99170-000, Brazil; Graduate Program in Bioexperimentation, Universidade de Passo Fundo, BR 285, São José, Passo Fundo, RS 99052-900, Brazil.
| | - Aline Pompermaier
- Graduate Program in Bioexperimentation, Universidade de Passo Fundo, BR 285, São José, Passo Fundo, RS 99052-900, Brazil.
| | - Hévilin Corrêa Dos Santos
- Biochemistry and Molecular Biology Laboratory Rosilene Rodrigues Kaizer, Federal Institute of Education, Science and Technology of Rio Grande do Sul, Campus Sertão, ERS 135, Km 25, Eng, Englert, RS, 99170-000, Brazil.
| | - Leonardo José Gil Barcellos
- Graduate Program in Pharmacology, Universidade Federal de Santa Maria, Av. Roraima, 1000, Cidade Universitária, Camobi, Santa Maria, RS 97105-900, Brazil; Graduate Program in Bioexperimentation, Universidade de Passo Fundo, BR 285, São José, Passo Fundo, RS 99052-900, Brazil.
| |
Collapse
|
10
|
Tamagno WA, Alves C, Pompermaier A, Vanin AP, Barcellos LJG. Household prallethrin-based insecticide toxicity on different C. elegans life stage: A possible sign of Huntington Disease. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 314:120301. [PMID: 36181934 DOI: 10.1016/j.envpol.2022.120301] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/05/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Household insecticide is largely used for insect and ectoparasite control, in city centers as well as in the countryside. The pyrethroids are the most used class of insecticide, these compounds in low doses have low toxicity for mammalians, in comparison to other compounds, with insecticide effects. The contact of these compounds in sublethal doses begins in early life and many cases, in intrauterine life. Considerable diseases still with undefined etiology, such as neurodegenerative conditions, and Huntington's Disease (HD) is one of them. HD is related to overexpression of Polyglutamine (PolyQ40), its aggregation, and non-solubilization, which leads to neural, behavioral, and cognitive damage. In our study, we evaluate the effect of two sublethal doses of a prallethrin-based insecticide (P-BI), in three different Caenorhabditis elegans life stages transgenerational, neonatal, and lifespan. We evaluated the Body bends and pharyngeal pumping rate, and social feeding as behavioral biomarkers. As well as acetylcholinesterase activity (AChE), PolyQ40 aggregation, antioxidant enzymes, and heat shock protein (HSP) expression. We observe that the toxic effect of P-BI is more pronounced on transgenerational and lifespan exposure. Both sublethal doses of P-BI decreased the AChE activity and retard the HSP expression as well as increased the PolyQ40 aggregates indicating a clear biomarker for possible effect in the progression of the HD, by the environmental contamination.
Collapse
Affiliation(s)
- Wagner Antonio Tamagno
- - Graduate Program in Pharmacology, Universidade Federal de Santa Maria, Av. Roraima, 1000, Cidade Universitária, Camobi, Santa Maria, RS, 97105-900, Brazil; - Biochemistry and Molecular Biology Laboratory Rosilene Rodrigues Kaizer, Federal Institute of Education, Science and Technology of Rio Grande Do Sul, Campus Sertão, ERS 135, Km 25, Eng. Englert, RS, 99170-000, Brazil.
| | - Carla Alves
- - Biochemistry and Molecular Biology Laboratory Rosilene Rodrigues Kaizer, Federal Institute of Education, Science and Technology of Rio Grande Do Sul, Campus Sertão, ERS 135, Km 25, Eng. Englert, RS, 99170-000, Brazil; - Graduate Program in Bioexperimentation Universidade de Passo Fundo, BR 285, São José, Passo Fundo, RS, 99052-900, Brazil.
| | - Aline Pompermaier
- - Graduate Program in Bioexperimentation Universidade de Passo Fundo, BR 285, São José, Passo Fundo, RS, 99052-900, Brazil.
| | - Ana Paula Vanin
- - Graduate Program in Science and Environmental Technology, Universidade Federal da Fronteira Sul, ERS 135, Erechim, RS, 99700-000, Brazil.
| | - Leonardo José Gil Barcellos
- - Graduate Program in Pharmacology, Universidade Federal de Santa Maria, Av. Roraima, 1000, Cidade Universitária, Camobi, Santa Maria, RS, 97105-900, Brazil; - Graduate Program in Bioexperimentation Universidade de Passo Fundo, BR 285, São José, Passo Fundo, RS, 99052-900, Brazil.
| |
Collapse
|
11
|
Hendi A, Niu LG, Snow AW, Ikegami R, Wang ZW, Mizumoto K. Channel-independent function of UNC-9/Innexin in spatial arrangement of GABAergic synapses in C. elegans. eLife 2022; 11:80555. [PMID: 36378164 PMCID: PMC9665852 DOI: 10.7554/elife.80555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 11/03/2022] [Indexed: 11/16/2022] Open
Abstract
Precise synaptic connection of neurons with their targets is essential for the proper functioning of the nervous system. A plethora of signaling pathways act in concert to mediate the precise spatial arrangement of synaptic connections. Here we show a novel role for a gap junction protein in controlling tiled synaptic arrangement in the GABAergic motor neurons in Caenorhabditis elegans, in which their axons and synapses overlap minimally with their neighboring neurons within the same class. We found that while EGL-20/Wnt controls axonal tiling, their presynaptic tiling is mediated by a gap junction protein UNC-9/Innexin, that is localized at the presynaptic tiling border between neighboring dorsal D-type GABAergic motor neurons. Strikingly, the gap junction channel activity of UNC-9 is dispensable for its function in controlling tiled presynaptic patterning. While gap junctions are crucial for the proper functioning of the nervous system as channels, our finding uncovered the novel channel-independent role of UNC-9 in synapse patterning.
Collapse
Affiliation(s)
- Ardalan Hendi
- Department of Zoology, University of British Columbia
- Life Sciences Institute, University of British Columbia
| | - Long-Gang Niu
- Department of Neuroscience, University of Connecticut Health Center
| | - Andrew William Snow
- Graduate Program in Cell and Developmental Biology, University of British Columbia
| | | | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center
| | - Kota Mizumoto
- Department of Zoology, University of British Columbia
- Life Sciences Institute, University of British Columbia
- Graduate Program in Cell and Developmental Biology, University of British Columbia
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia
| |
Collapse
|
12
|
Filipowicz A, Lalsiamthara J, Aballay A. Dissection of a sensorimotor circuit underlying pathogen aversion in C. elegans. BMC Biol 2022; 20:229. [PMID: 36209082 PMCID: PMC9548130 DOI: 10.1186/s12915-022-01424-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/28/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Altering animal behavior to reduce pathogen exposure is a key line of defense against pathogen attack. In Caenorhabditis elegans, alterations in intestinal physiology caused by pathogen colonization and sensation of microbial metabolites may lead to activation of pathogen aversive behaviors ranging from aversive reflexes to learned avoidance. However, the neural circuitry between chemosensory neurons that sense pathogenic bacterial cues and the motor neurons responsible for avoidance-associated locomotion remains unknown. RESULTS Using C. elegans, we found that backward locomotion was a component of learned pathogen avoidance, as animals pre-exposed to Pseudomonas aeruginosa or Enterococcus faecalis showed reflexive aversion to drops of the bacteria driven by chemosensory neurons, including the olfactory AWB neurons. This response also involved intestinal distention and, for E. faecalis, required expression of TRPM channels in the intestine and excretory system. Additionally, we uncovered a circuit composed of olfactory neurons, interneurons, and motor neurons that controls the backward locomotion crucial for learned reflexive aversion to pathogenic bacteria, learned avoidance, and the repulsive odor 2-nonanone. CONCLUSIONS Using whole-brain simulation and functional assays, we uncovered a novel sensorimotor circuit governing learned reflexive aversion. The discovery of a complete sensorimotor circuit for reflexive aversion demonstrates the utility of using the C. elegans connectome and computational modeling in uncovering new neuronal regulators of behavior.
Collapse
Affiliation(s)
- Adam Filipowicz
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA
- Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Jonathan Lalsiamthara
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Alejandro Aballay
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA.
| |
Collapse
|
13
|
Chai CM, Park H, Sternberg PW. Brain-wide bidirectional neuropeptide modulation of individual neuron classes regulates a developmental decision. Curr Biol 2022; 32:3365-3373.e6. [PMID: 35679871 PMCID: PMC10588560 DOI: 10.1016/j.cub.2022.05.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/06/2022] [Accepted: 05/17/2022] [Indexed: 11/18/2022]
Abstract
Secreted neuromodulators, like biogenic amines and neuropeptides, can reconfigure circuit functions both locally and at a distance and establish global brain states that alter circuit outputs over prolonged timescales.1-3 Despite their diversity and ubiquitous presence, many studies on neuromodulation tend to focus on dissecting the function and site of action of individual neuropeptides. Here, we take a different approach by conducting a systems-level investigation of neuropeptide receptor signaling function and cell-type-specific distribution in the context of the Caenorhabditis elegans diapause entry developmental decision. C. elegans diapause entry is controlled by sensory perception of external factors and is regulated by neuropeptide signaling.4-8 We performed a comprehensive functional screen of neuropeptide receptor mutants for pheromone-induced diapause entry phenotypes and integrated these results with published C. elegans single-cell RNA-seq data to reveal that almost all neuron classes expressed at least one receptor with a role in diapause entry.9 Our receptor expression analysis also identified four highly modulated neural hubs with no previously reported roles in diapause entry that are distributed throughout the animal's body, possibly as a means of synchronizing the whole-organism transition into the appropriate larval morph. Furthermore, most neuron classes expressed unique neuropeptide receptor repertoires that have opposing effects on the diapause entry decision. We propose that brain-wide antagonistic neuropeptide modulation of individual neuron classes by distinct neuropeptide receptor subsets could serve as a strategy against overmodulation and that this motif might generalize to other decision-making paradigms in other organisms.
Collapse
Affiliation(s)
- Cynthia M Chai
- Division of Biology & Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA.
| | - Heenam Park
- Division of Biology & Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA
| | - Paul W Sternberg
- Division of Biology & Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA.
| |
Collapse
|
14
|
Zhang Y, Zhao C, Zhang H, Lu Q, Zhou J, Liu R, Wang S, Pu Y, Yin L. Trans-generational effects of copper on nerve damage in Caenorhabditis elegans. CHEMOSPHERE 2021; 284:131324. [PMID: 34225113 DOI: 10.1016/j.chemosphere.2021.131324] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/20/2021] [Accepted: 06/22/2021] [Indexed: 05/15/2023]
Abstract
The potential toxicity of copper has received great attention for a long time, however, trans-generational effects of copper have not been extensively investigated. Caenorhabditis elegans (C. elegans) was used to evaluate the trans-generational toxicities of copper several physiological endpoints: growth, head thrashes and body bends and degree of neuronal damage. Copper significantly inhibited growth, body bends, head thrashes and caused degeneration of dopaminergic neurons in a concentration-dependent manner in parental worms. Further we found oxidative damage was to underlying the onset of neuron degeneration. In our study copper promoted ROS accumulation, and led to an increased expression of the oxidative stress response-related genes sod-3 and a decreased expression of metal detoxification genes mtl-1 and mtl-2. Moreover, copper increased the fluorescence intensity of the transgenic strain that encodes the antioxidant enzyme SOD-3. Gradually decline in copper-induced impairments were observed in the filial generations without exposure. No growth impairment was shown in F3, the trend of head thrashes recovery gradually appeared in F2 and no growth impairment was shown in F3, the body bends impairment caused by the parental copper exposure was recovery until F4 and no growth impairment was shown in F5. Besides, dopamine neurons revealed damage related to neurobehavioral endpoints, with hereditary effects in the progeny together. In addition, sequencing results suggested that copper exposure could cause epigenetic changes. QRT-PCR results showed that differentially expressed genes can also be passed on to offspring.
Collapse
Affiliation(s)
- Ying Zhang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Chao Zhao
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Hu Zhang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Qiang Lu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Jingjing Zhou
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Ran Liu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Shizhi Wang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Yuepu Pu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| | - Lihong Yin
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
| |
Collapse
|
15
|
Sordillo A, Bargmann CI. Behavioral control by depolarized and hyperpolarized states of an integrating neuron. eLife 2021; 10:e67723. [PMID: 34738904 PMCID: PMC8570696 DOI: 10.7554/elife.67723] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 10/19/2021] [Indexed: 12/11/2022] Open
Abstract
Coordinated transitions between mutually exclusive motor states are central to behavioral decisions. During locomotion, the nematode Caenorhabditis elegans spontaneously cycles between forward runs, reversals, and turns with complex but predictable dynamics. Here, we provide insight into these dynamics by demonstrating how RIM interneurons, which are active during reversals, act in two modes to stabilize both forward runs and reversals. By systematically quantifying the roles of RIM outputs during spontaneous behavior, we show that RIM lengthens reversals when depolarized through glutamate and tyramine neurotransmitters and lengthens forward runs when hyperpolarized through its gap junctions. RIM is not merely silent upon hyperpolarization: RIM gap junctions actively reinforce a hyperpolarized state of the reversal circuit. Additionally, the combined outputs of chemical synapses and gap junctions from RIM regulate forward-to-reversal transitions. Our results indicate that multiple classes of RIM synapses create behavioral inertia during spontaneous locomotion.
Collapse
Affiliation(s)
- Aylesse Sordillo
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller UniversityNew YorkUnited States
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller UniversityNew YorkUnited States
- Chan Zuckerberg InitiativeRedwood CityUnited States
| |
Collapse
|
16
|
Ferkey DM, Sengupta P, L’Etoile ND. Chemosensory signal transduction in Caenorhabditis elegans. Genetics 2021; 217:iyab004. [PMID: 33693646 PMCID: PMC8045692 DOI: 10.1093/genetics/iyab004] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/05/2021] [Indexed: 12/16/2022] Open
Abstract
Chemosensory neurons translate perception of external chemical cues, including odorants, tastants, and pheromones, into information that drives attraction or avoidance motor programs. In the laboratory, robust behavioral assays, coupled with powerful genetic, molecular and optical tools, have made Caenorhabditis elegans an ideal experimental system in which to dissect the contributions of individual genes and neurons to ethologically relevant chemosensory behaviors. Here, we review current knowledge of the neurons, signal transduction molecules and regulatory mechanisms that underlie the response of C. elegans to chemicals, including pheromones. The majority of identified molecules and pathways share remarkable homology with sensory mechanisms in other organisms. With the development of new tools and technologies, we anticipate that continued study of chemosensory signal transduction and processing in C. elegans will yield additional new insights into the mechanisms by which this animal is able to detect and discriminate among thousands of chemical cues with a limited sensory neuron repertoire.
Collapse
Affiliation(s)
- Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Noelle D L’Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, CA 94143, USA
| |
Collapse
|
17
|
Meng L, Yan D. NLR-1/CASPR Anchors F-Actin to Promote Gap Junction Formation. Dev Cell 2020; 55:574-587.e3. [PMID: 33238150 DOI: 10.1016/j.devcel.2020.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 08/05/2020] [Accepted: 10/28/2020] [Indexed: 12/31/2022]
Abstract
Gap junctions are present in most tissues and play essential roles in various biological processes. However, we know surprisingly little about the molecular mechanisms underlying gap junction formation. Here, we uncover the essential role of a conserved EGF- and laminin-G-domain-containing protein nlr-1/CASPR in the regulation of gap junction formation in multiple tissues across different developmental stages in C. elegans. NLR-1 is located in the gap junction perinexus, a region adjacent to but not overlapping with gap junctions, and forms puncta before the clusters of gap junction channels appear on the membrane. We show that NLR-1 can directly bind to actin to recruit F-actin networks at the gap junction formation plaque, and the formation of F-actin patches plays a critical role in the assembly of gap junction channels. Our findings demonstrate that nlr-1/CASPR acts as an early stage signal for gap junction formation through anchoring of F-actin networks.
Collapse
Affiliation(s)
- Lingfeng Meng
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Dong Yan
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Regeneration Next, and Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 27710, USA.
| |
Collapse
|
18
|
Abstract
For the first 25 years after the landmark 1974 paper that launched the field, most C. elegans biologists were content to think of their subjects as solitary creatures. C. elegans presented no shortage of fascinating biological problems, but some of the features that led Brenner to settle on this species-in particular, its free-living, self-fertilizing lifestyle-also seemed to reduce its potential for interesting social behavior. That perspective soon changed, with the last two decades bringing remarkable progress in identifying and understanding the complex interactions between worms. The growing appreciation that C. elegans behavior can only be meaningfully understood in the context of its ecology and evolution ensures that the coming years will see similarly exciting progress.
Collapse
Affiliation(s)
- Douglas S Portman
- Departments of Biomedical Genetics, Neuroscience, and Biology, Del Monte Institute for Neuroscience, University of Rochester, Rochester, NY, USA
| |
Collapse
|
19
|
Shui Y, Liu P, Zhan H, Chen B, Wang ZW. Molecular basis of junctional current rectification at an electrical synapse. SCIENCE ADVANCES 2020; 6:eabb3076. [PMID: 32923588 PMCID: PMC7455501 DOI: 10.1126/sciadv.abb3076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
Rectifying electrical synapses (RESs) exist across animal species, but their rectification mechanism is largely unknown. We investigated why RESs between AVA premotor interneurons and A-type cholinergic motoneurons (A-MNs) in Caenorhabditis elegans escape circuit conduct junctional currents (I j) only in the antidromic direction. These RESs consist of UNC-7 innexin in AVA and UNC-9 innexin in A-MNs. UNC-7 has multiple isoforms differing in the length and sequence of the amino terminus. In a heterologous expression system, only one UNC-7 isoform, UNC-7b, can form heterotypic gap junctions (GJs) with UNC-9 that strongly favor I j in the UNC-9 to UNC-7 direction. Knockout of unc-7b alone almost eliminated the I j, whereas AVA-specific expression of UNC-7b substantially rescued the coupling defect of unc-7 mutant. Neutralizing charged residues in UNC-7b amino terminus abolished the rectification property of UNC-7b/UNC-9 GJs. Our results suggest that the rectification property results from electrostatic interactions between charged residues in UNC-7b amino terminus.
Collapse
Affiliation(s)
- Yuan Shui
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT 06030, USA
| | | | | | | | | |
Collapse
|
20
|
Yoshimura R, Suetsugu T, Kawahara A, Nakata K, Shikata M, Tanaka S, Ono T, Fushiki D, Endo Y. Formation of functional innexin hemichannels, as well as gap junctional channels, in an insect cell line, NIAs-AeAl-2, derived from Asian tiger mosquito Aedes albopictus (Diptera: Culicidae): A partial but significant contribution of innexin 2. JOURNAL OF INSECT PHYSIOLOGY 2020; 124:104060. [PMID: 32446763 DOI: 10.1016/j.jinsphys.2020.104060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 05/18/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
In vertebrates, gap junctions and hemichannels consisting of connexins are important cell surface structures for communication with neighboring cells and for the regulation of various cell functions. To date, various gap-junction-related proteins have been found, including innexins in invertebrates and pannexins in vertebrates. Significant contributions of gap junctions by innexins and (hemi-)channels by pannexins to numerous functions have been reported. Verification of the presence and functional significance of innexin hemichannels, however, remains a gap in our knowledge in innexin physiology. In this study, we revealed the localization of an innexin protein (innexin 2) on the cell surface in mosquito tissues and cultured cells. Furthermore, we demonstrated the presence of functional hemichannels, as well as gap junctions, in mosquito cells using dye transfer assays. The inward uptake of fluorescent dye was inhibited by anti-innexin 2 antibody. These results suggest that innexin hemichannels are formed to function in cultured mosquito cells, in at least a partially innexin 2-dependent manner. Although only a few studies on insect hemichannels have been published, innexin-based hemichannels, as well as innexin gap junctions, could also significantly contribute to insect intercellular signal transduction.
Collapse
Affiliation(s)
- Ryoichi Yoshimura
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan.
| | - Taeko Suetsugu
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan; Laboratory for Cell Asymmetry, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuo-Ku, Kobe, Hyogo 650-0047, Japan
| | - Ai Kawahara
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan
| | - Kana Nakata
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan
| | - Masato Shikata
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan
| | - Souma Tanaka
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan
| | - Tsutomu Ono
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan
| | - Daisuke Fushiki
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan
| | - Yasuhisa Endo
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Kyoto 606-8585, Japan
| |
Collapse
|
21
|
Tsukamoto S, Emmei T, Nakano S, Nishio N, Sasakura H, Mori I. The Caenorhabditis elegans INX-4/Innexin is required for the fine-tuning of temperature orientation in thermotaxis behavior. Genes Cells 2020; 25:154-164. [PMID: 31917862 PMCID: PMC7078936 DOI: 10.1111/gtc.12745] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 12/27/2019] [Accepted: 12/28/2019] [Indexed: 01/10/2023]
Abstract
Innexins in invertebrates are considered to play roles similar to those of connexins and pannexins in vertebrates. However, it remains poorly understood how innexins function in biological phenomena including their function in the nervous systems. Here, we identified inx‐4, a member of the innexin family in C. elegans, by a forward screening of thermotaxis‐defective mutants. The inx‐4 mutants exhibited abnormal migration to a temperature slightly higher than the cultivation temperature, called mild thermophilic behavior. Rescue experiments revealed that INX‐4 acts in the major thermosensory neuron AFD to regulate thermotaxis behavior. INX‐4::GFP fusion protein localized exclusively along axons in AFD neurons. In addition, over‐expression of INX‐4 in AFD neurons induced a cryophilic behavior, which is opposite to inx-4 mutants. Our findings suggest that INX‐4/Innexin in AFD may fine‐tune the execution of thermotaxis behavior when moving to desired temperatures.
Collapse
Affiliation(s)
- Satomi Tsukamoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Taishi Emmei
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Shunji Nakano
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.,Neuroscience Institute, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Nana Nishio
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Hiroyuki Sasakura
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Ikue Mori
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.,Neuroscience Institute, Graduate School of Science, Nagoya University, Nagoya, Japan
| |
Collapse
|
22
|
Activity-Dependent Regulation of the Proapoptotic BH3-Only Gene egl-1 in a Living Neuron Pair in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2019; 9:3703-3714. [PMID: 31519744 PMCID: PMC6829140 DOI: 10.1534/g3.119.400654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The BH3-only family of proteins is key for initiating apoptosis in a variety of contexts, and may also contribute to non-apoptotic cellular processes. Historically, the nematode Caenorhabditis elegans has provided a powerful system for studying and identifying conserved regulators of BH3-only proteins. In C. elegans, the BH3-only protein egl-1 is expressed during development to cell-autonomously trigger most developmental cell deaths. Here we provide evidence that egl-1 is also transcribed after development in the sensory neuron pair URX without inducing apoptosis. We used genetic screening and epistasis analysis to determine that its transcription is regulated in URX by neuronal activity and/or in parallel by orthologs of Protein Kinase G and the Salt-Inducible Kinase family. Because several BH3-only family proteins are also expressed in the adult nervous system of mammals, we suggest that studying egl-1 expression in URX may shed light on mechanisms that regulate conserved family members in higher organisms.
Collapse
|
23
|
Zhou L, Huang PP, Chen LL, Wang P. Panax Notoginseng Saponins Ameliorate A β-Mediated Neurotoxicity in C. elegans through Antioxidant Activities. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2019; 2019:7621043. [PMID: 31275419 PMCID: PMC6582912 DOI: 10.1155/2019/7621043] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 05/21/2019] [Indexed: 11/25/2022]
Abstract
The deposition of amyloid beta (Aβ) is the main hallmark of Alzheimer's disease (AD) and there is no effective drug to cure the progressive cognitive loss or memory deficits caused by the aggregative toxicity of Aβ protein. Oxidative stress has been hypothesized to play a role in progressive neurodegenerative diseases like AD. Panax notoginseng saponin (PNS) from the rhizome of "pseudo-ginseng" exhibits potent antioxidant effects on aging process in neuron cells and animals. By using C. elegans as an ideal model organism, the present study shows that PNS (0.5-4 mg/mL) can significantly inhibit AD-like symptoms of worm paralysis and enhance resistance to oxidative stress induced by paraquat and aging conditions. Additionally, PNS extends lifespan and maintains healthspan of C. elegans by improving the swimming prowess and fertility at old age. It markedly activates the expression of SKN-1 mRNA, which further supports SKN-1 signaling pathway which is involved in the therapeutic effect of PNS on AD C. elegans. Our results provide direct evidence on PNS for treating AD on gene level and theoretical foundation for reshaping medicinal products of PNS in the future.
Collapse
Affiliation(s)
- Ling Zhou
- School of Basic Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Pan-Pan Huang
- School of Basic Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Lin-Lin Chen
- Key Laboratory of Traditional Chinese Medicine Resource and Compound Prescription, Ministry of Education, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Ping Wang
- School of Basic Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China
| |
Collapse
|
24
|
Ding SS, Schumacher LJ, Javer AE, Endres RG, Brown AEX. Shared behavioral mechanisms underlie C. elegans aggregation and swarming. eLife 2019; 8:e43318. [PMID: 31021320 PMCID: PMC6522220 DOI: 10.7554/elife.43318] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 04/19/2019] [Indexed: 11/13/2022] Open
Abstract
In complex biological systems, simple individual-level behavioral rules can give rise to emergent group-level behavior. While collective behavior has been well studied in cells and larger organisms, the mesoscopic scale is less understood, as it is unclear which sensory inputs and physical processes matter a priori. Here, we investigate collective feeding in the roundworm C. elegans at this intermediate scale, using quantitative phenotyping and agent-based modeling to identify behavioral rules underlying both aggregation and swarming-a dynamic phenotype only observed at longer timescales. Using fluorescence multi-worm tracking, we quantify aggregation in terms of individual dynamics and population-level statistics. Then we use agent-based simulations and approximate Bayesian inference to identify three key behavioral rules for aggregation: cluster-edge reversals, a density-dependent switch between crawling speeds, and taxis towards neighboring worms. Our simulations suggest that swarming is simply driven by local food depletion but otherwise employs the same behavioral mechanisms as the initial aggregation.
Collapse
Affiliation(s)
- Siyu Serena Ding
- Instititue of Clinical SciencesImperial College LondonLondonUnited Kingdom
- MRC London Institute of Medical SciencesLondonUnited Kingdom
| | - Linus J Schumacher
- Department of Life SciencesImperial College LondonLondonUnited Kingdom
- MRC Centre for Regenerative MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Avelino E Javer
- Instititue of Clinical SciencesImperial College LondonLondonUnited Kingdom
- MRC London Institute of Medical SciencesLondonUnited Kingdom
| | - Robert G Endres
- Department of Life SciencesImperial College LondonLondonUnited Kingdom
| | - André EX Brown
- Instititue of Clinical SciencesImperial College LondonLondonUnited Kingdom
- MRC London Institute of Medical SciencesLondonUnited Kingdom
| |
Collapse
|
25
|
Miller CT, Hale ME, Okano H, Okabe S, Mitra P. Comparative Principles for Next-Generation Neuroscience. Front Behav Neurosci 2019; 13:12. [PMID: 30787871 PMCID: PMC6373779 DOI: 10.3389/fnbeh.2019.00012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/15/2019] [Indexed: 01/10/2023] Open
Abstract
Neuroscience is enjoying a renaissance of discovery due in large part to the implementation of next-generation molecular technologies. The advent of genetically encoded tools has complemented existing methods and provided researchers the opportunity to examine the nervous system with unprecedented precision and to reveal facets of neural function at multiple scales. The weight of these discoveries, however, has been technique-driven from a small number of species amenable to the most advanced gene-editing technologies. To deepen interpretation and build on these breakthroughs, an understanding of nervous system evolution and diversity are critical. Evolutionary change integrates advantageous variants of features into lineages, but is also constrained by pre-existing organization and function. Ultimately, each species’ neural architecture comprises both properties that are species-specific and those that are retained and shared. Understanding the evolutionary history of a nervous system provides interpretive power when examining relationships between brain structure and function. The exceptional diversity of nervous systems and their unique or unusual features can also be leveraged to advance research by providing opportunities to ask new questions and interpret findings that are not accessible in individual species. As new genetic and molecular technologies are added to the experimental toolkits utilized in diverse taxa, the field is at a key juncture to revisit the significance of evolutionary and comparative approaches for next-generation neuroscience as a foundational framework for understanding fundamental principles of neural function.
Collapse
Affiliation(s)
- Cory T Miller
- Cortical Systems and Behavior Laboratory, Neurosciences Graduate Program, University of California, San Diego, San Diego, CA, United States
| | - Melina E Hale
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, United States
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan.,Laboratory for Marmoset Neural Architecture, RIKEN Center for Brain Science (CBS), Wako, Japan
| | - Shigeo Okabe
- Department of Cellular Neurobiology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | - Partha Mitra
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States
| |
Collapse
|
26
|
Axon-Dependent Patterning and Maintenance of Somatosensory Dendritic Arbors. Dev Cell 2019; 48:229-244.e4. [PMID: 30661986 DOI: 10.1016/j.devcel.2018.12.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 11/12/2018] [Accepted: 12/16/2018] [Indexed: 12/20/2022]
Abstract
The mechanisms that pattern and maintain dendritic arbors are key to understanding the principles that govern nervous system assembly. The activity of presynaptic axons has long been known to shape dendrites, but activity-independent functions of axons in this process have remained elusive. Here, we show that in Caenorhabditis elegans, the axons of the ALA neuron control guidance and extension of the 1° dendrites of PVD somatosensory neurons independently of ALA activity. PVD 1° dendrites mimic ALA axon guidance defects in loss-of-function mutants for the extracellular matrix molecule MIG-6/Papilin or the UNC-6/Netrin pathway, suggesting that axon-dendrite adhesion is important for dendrite formation. We found that the SAX-7/L1CAM cell adhesion molecule engages in distinct molecular mechanisms to mediate extensions of PVD 1° dendrites and maintain the ALA-PVD axon-dendritic fascicle, respectively. Thus, axons can serve as critical scaffolds to pattern and maintain dendrites through contact-dependent but activity-independent mechanisms.
Collapse
|
27
|
Zhao Y, Long L, Xu W, Campbell RF, Large EE, Greene JS, McGrath PT. Changes to social feeding behaviors are not sufficient for fitness gains of the Caenorhabditis elegans N2 reference strain. eLife 2018; 7:38675. [PMID: 30328811 PMCID: PMC6224195 DOI: 10.7554/elife.38675] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/15/2018] [Indexed: 12/15/2022] Open
Abstract
The standard reference Caenorhabditis elegans strain, N2, has evolved marked behavioral changes in social feeding behavior since its isolation from the wild. We show that the causal, laboratory-derived mutations in two genes, npr-1 and glb-5, confer large fitness advantages in standard laboratory conditions. Using environmental manipulations that suppress social/solitary behavior differences, we show the fitness advantages of the derived alleles remained unchanged, suggesting selection on these alleles acted through pleiotropic traits. Transcriptomics, developmental timing, and food consumption assays showed that N2 animals mature faster, produce more sperm, and consume more food than a strain containing ancestral alleles of these genes regardless of behavioral strategies. Our data suggest that the pleiotropic effects of glb-5 and npr-1 are a consequence of changes to O2 -sensing neurons that regulate both aerotaxis and energy homeostasis. Our results demonstrate how pleiotropy can lead to profound behavioral changes in a popular laboratory model. Why do humans walk on two feet? And what makes us smarter than our ape ancestors? The answers to these questions, and countless others about the particular traits of any number of species, is often said to be natural selection – a process where genes that ensure the survival of a species are favored of others. But it is not always the answer. Other evolutionary forces, such as random changes to the frequency of certain gene variants, restrictions on the development of a certain trait and pleiotropy (where one gene influences other, seemingly unrelated traits) can also cause differences between species. Designing experiments to test whether a trait difference is due to natural selection or other factors is notoriously difficult. However, the humble nematode worm, Caenorhabditis elegans, has proven to be particularly useful in this respect. One subtype or strain of C. elegans with certain changes to its genes is used internationally as a ‘reference strain’, to ensure results between labs are comparable. This strain, N2, has been bred in the laboratory for hundreds of generations, isolated from its wild counterparts. N2 shows several differences in behavior from the wildtype, including its feeding habits. Wild C. elegans tend to feed together socially, whereas N2 prefers to feed alone. In 1998 and 2009, researchers – including some involved in the current study – have identified the genetic modifications responsible for this change in behavior. Now, Zhao et al. set out to determine whether this was due to natural selection, and if so, was there a benefit to solitary feeding in laboratory conditions that was driving this genetic change? Zhao et al. found that the genetic changes in the N2 strain gave the worms a considerable advantage in the artificial environment. However, experiments to modify the conditions the animals grew in revealed that the solitary feeding habits were not necessary for the fitness advantage. In other words, the changes in feeding habits were a symptom of the genetic changes that gave N2 a selective advantage, but they were not the cause. In other words, the changes in feeding behavior were not a result of natural selection, but rather of pleiotropy. The findings highlight that not every change in a trait is down to natural selection and must therefore be put to the test. With declining costs of DNA sequencing, researchers can now easily identify genes and regions of DNA that are likely to be under selection. However, they must be careful before leaping to the conclusion that behavioral differences linked to genetic changes are adaptive. In addition, the findings show that the laboratories relying on N2 as a model organism should be aware that the strain has evolved fundamental differences in its brain connections compared with the wildtype.
Collapse
Affiliation(s)
- Yuehui Zhao
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Lijiang Long
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Wen Xu
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Richard F Campbell
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Edward E Large
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | | | - Patrick T McGrath
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States.,Department of Physics, Georgia Institute of Technology, Atlanta, United States.,Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, United States
| |
Collapse
|
28
|
Güiza J, Barría I, Sáez JC, Vega JL. Innexins: Expression, Regulation, and Functions. Front Physiol 2018; 9:1414. [PMID: 30364195 PMCID: PMC6193117 DOI: 10.3389/fphys.2018.01414] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 09/18/2018] [Indexed: 01/02/2023] Open
Abstract
The innexin (Inx) proteins form gap junction channels and non-junctional channels (named hemichannels) in invertebrates. These channels participate in cellular communication playing a relevant role in several physiological processes. Pioneer studies conducted mainly in worms and flies have shown that innexins participate in embryo development and behavior. However, recent studies have elucidated new functions of innexins in Arthropoda, Nematoda, Annelida, and Cnidaria, such as immune response, and apoptosis. This review describes emerging data of possible new roles of innexins and summarizes the data available to date.
Collapse
Affiliation(s)
- Juan Güiza
- Laboratorio de Fisiología Experimental, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Iván Barría
- Laboratorio de Fisiología Experimental, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Juan C Sáez
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile.,Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - José L Vega
- Laboratorio de Fisiología Experimental, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| |
Collapse
|
29
|
Dennis EJ, Dobosiewicz M, Jin X, Duvall LB, Hartman PS, Bargmann CI, Vosshall LB. A natural variant and engineered mutation in a GPCR promote DEET resistance in C. elegans. Nature 2018; 562:119-123. [PMID: 30258230 DOI: 10.1038/s41586-018-0546-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 07/27/2018] [Indexed: 12/16/2022]
Abstract
DEET (N,N-diethyl-meta-toluamide) is a synthetic chemical identified by the US Department of Agriculture in 1946 in a screen for repellents to protect soldiers from mosquito-borne diseases1,2. Since its discovery, DEET has become the world's most widely used arthropod repellent and is effective against invertebrates separated by millions of years of evolution-including biting flies3, honeybees4, ticks5, and land leeches3. In insects, DEET acts on the olfactory system5-12 and requires the olfactory receptor co-receptor Orco7,9-12, but exactly how it works remains controversial13. Here we show that the nematode Caenorhabditis elegans is sensitive to DEET and use this genetically tractable animal to study the mechanism of action of this chemical. We found that DEET is not a volatile repellent, but instead interferes selectively with chemotaxis to a variety of attractant and repellent molecules. In a forward genetic screen for DEET-resistant worms, we identified a gene that encodes a single G protein-coupled receptor, str-217, which is expressed in a single pair of chemosensory neurons that are responsive to DEET, called ADL neurons. Mis-expression of str-217 in another chemosensory neuron conferred responses to DEET. Engineered str-217 mutants, and a wild isolate of C. elegans that carries a str-217 deletion, are resistant to DEET. We found that DEET can interfere with behaviour by inducing an increase in average pause length during locomotion, and show that this increase in pausing requires both str-217 and ADL neurons. Finally, we demonstrated that ADL neurons are activated by DEET and that optogenetic activation of ADL neurons increased average pause length. This is consistent with the 'confusant' hypothesis, which proposes that DEET is not a simple repellent but that it instead modulates multiple olfactory pathways to scramble behavioural responses10,11. Our results suggest a consistent motif in the effectiveness of DEET across widely divergent taxa: an effect on multiple chemosensory neurons that disrupts the pairing between odorant stimulus and behavioural response.
Collapse
Affiliation(s)
- Emily J Dennis
- Laboratory of Neurogenetics and Behaviour, The Rockefeller University, New York, NY, USA
| | - May Dobosiewicz
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behaviour, The Rockefeller University, New York, NY, USA
| | - Xin Jin
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behaviour, The Rockefeller University, New York, NY, USA.,Society of Fellows, Harvard University, Cambridge, MA, USA
| | - Laura B Duvall
- Laboratory of Neurogenetics and Behaviour, The Rockefeller University, New York, NY, USA
| | - Philip S Hartman
- Department of Biology, Texas Christian University, Fort Worth, TX, USA
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behaviour, The Rockefeller University, New York, NY, USA.,Kavli Neural Systems Institute, New York, NY, USA
| | - Leslie B Vosshall
- Laboratory of Neurogenetics and Behaviour, The Rockefeller University, New York, NY, USA. .,Kavli Neural Systems Institute, New York, NY, USA. .,Howard Hughes Medical Institute, New York, NY, USA.
| |
Collapse
|
30
|
McGrath PT, Ruvinsky I. A primer on pheromone signaling in Caenorhabditis elegans for systems biologists. ACTA ACUST UNITED AC 2018; 13:23-30. [PMID: 30984890 DOI: 10.1016/j.coisb.2018.08.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Individuals communicate information about their age, sex, social status, and recent life history with other members of their species through the release of pheromones, chemical signals that elicit behavioral or physiological changes in the recipients. Pheromones provide a fascinating example of information exchange: animals have evolved intraspecific languages in the presence of eavesdroppers and cheaters. In this review, we discuss the recent work using the nematode C. elegans to decipher its chemical language through the analysis of ascaroside pheromones. Genetic dissection has started to identify the enzymes that produce pheromones and the neural circuits that process these signals. Ecological experiments have characterized the biotic environment of C. elegans and its relatives, including ecological relationships with a variety of species that sense or release similar blends of ascarosides. Systems biology approaches should be fruitful in understanding the organization and function of communication systems in C. elegans.
Collapse
Affiliation(s)
- Patrick T McGrath
- Department of Biological Sciences, Department of Physics; Georgia Institute of Technology, Atlanta, GA 30332.
| | - Ilya Ruvinsky
- Department of Molecular Biosciences; Northwestern University, Evanston, IL 60208.
| |
Collapse
|
31
|
Hori S, Oda S, Suehiro Y, Iino Y, Mitani S. OFF-responses of interneurons optimize avoidance behaviors depending on stimulus strength via electrical synapses. PLoS Genet 2018; 14:e1007477. [PMID: 29939997 PMCID: PMC6034901 DOI: 10.1371/journal.pgen.1007477] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 07/06/2018] [Accepted: 06/07/2018] [Indexed: 12/21/2022] Open
Abstract
Optimization of the types and timing of avoidance behaviors depending on the intensity of a noxious stimulus is essential for survival; however, processing in the central nervous system and its developmental basis are largely unknown. Here, we report that Caenorhabditis elegans preferentially selects one of three different types of avoidance behaviors depending on the strength of the noxious stimulus. We screened 210 neuronal transcription factors using a combination of optogenetics and RNA interference methods and identified 19 candidates required for avoidance behaviors. One candidate, gene lin-32 (abnormal cellLINeage32), which encodes an atonal homolog, is required for the neural fate determination of AIB interneurons and functions by regulating the expression of electrical and chemical synapse genes, namely, inx-1 (innexin 1) and AMPA-type ionotropic glutamate receptor glr-1. When examined by Ca imaging, AIB showed an OFF calcium increase to the noxious stimulus. The OFF calcium increase was provoked only by strong stimulation, suggesting a role for optimization of the avoidance behavior. However, lin-32 mutants showed an impaired AIB OFF calcium increase, concomitant with a reduced occurrence of the dynamic avoidance behavior called the "omega turn". The AIB neural responses may be transferred to downstream inter/motor neurons projecting to the neck muscles via electrical synapses comprising inx-1. Finally, we found a correlation between powerful contractions of the neck muscles and omega turns. Thus, the central regulation of the magnitude and timing of activation of the AIB interneurons optimizes the probability of omega turn depending on the stimulus context. For survival, animals exhibit appropriate behaviors depending on the type and strength of a stimulus; however, processing in the central nervous system and its developmental basis are largely unknown. Here, we performed RNA interference screening of 210 transcription factors by observing the avoidance behaviors evoked by a harmful stimulus and identified 19 candidates with behavioral defects. One candidate gene, lin-32, which encodes a homologue of a well-conserved transcription factor, atonal, that plays a key role in cell type specification, is required for the optimization of avoidance behaviors. lin-32 regulates the expression of various synaptic genes in the key neurons required for the optimization of avoidance behaviors. The key neurons respond at the time of the removal of the strong stimulation, and an appropriate magnitude and timing of the calcium increase are required to determine the type and timing of dynamic avoidance behaviors. However, the key neuronal response does not occur in the lin-32 mutants. Activation of the key neurons may be transferred to the downstream neurons projecting to the neck muscles via electrical synapses. Finally, we show a correlation between powerful neck muscle contractions and dynamic avoidance behaviors.
Collapse
Affiliation(s)
- Sayaka Hori
- Department of Physiology, Tokyo Women’s Medical University School of Medicine, Tokyo, Japan
| | - Shigekazu Oda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuji Suehiro
- Department of Physiology, Tokyo Women’s Medical University School of Medicine, Tokyo, Japan
| | - Yuichi Iino
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women’s Medical University School of Medicine, Tokyo, Japan
- * E-mail:
| |
Collapse
|
32
|
Abstract
How the brain effectively switches between and maintains global states, such as sleep and wakefulness, is not yet understood. We used brainwide functional imaging at single-cell resolution to show that during the developmental stage of lethargus, the Caenorhabditis elegans brain is predisposed to global quiescence, characterized by systemic down-regulation of neuronal activity. Only a few specific neurons are exempt from this effect. In the absence of external arousing cues, this quiescent brain state arises by the convergence of neuronal activities toward a fixed-point attractor embedded in an otherwise dynamic neural state space. We observed efficient spontaneous and sensory-evoked exits from quiescence. Our data support the hypothesis that during global states such as sleep, neuronal networks are drawn to a baseline mode and can be effectively reactivated by signaling from arousing circuits.
Collapse
Affiliation(s)
- Annika L A Nichols
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Tomáš Eichler
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Richard Latham
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Manuel Zimmer
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
| |
Collapse
|