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Belghazi M, Iborra C, Toutendji O, Lasserre M, Debanne D, Goaillard JM, Marquèze-Pouey B. High-Resolution Proteomics Unravel a Native Functional Complex of Cav1.3, SK3, and Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels in Midbrain Dopaminergic Neurons. Cells 2024; 13:944. [PMID: 38891076 PMCID: PMC11172389 DOI: 10.3390/cells13110944] [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: 03/04/2024] [Revised: 05/21/2024] [Accepted: 05/26/2024] [Indexed: 06/21/2024] Open
Abstract
Pacemaking activity in substantia nigra dopaminergic neurons is generated by the coordinated activity of a variety of distinct somatodendritic voltage- and calcium-gated ion channels. We investigated whether these functional interactions could arise from a common localization in macromolecular complexes where physical proximity would allow for efficient interaction and co-regulations. For that purpose, we immunopurified six ion channel proteins involved in substantia nigra neuron autonomous firing to identify their molecular interactions. The ion channels chosen as bait were Cav1.2, Cav1.3, HCN2, HCN4, Kv4.3, and SK3 channel proteins, and the methods chosen to determine interactions were co-immunoprecipitation analyzed through immunoblot and mass spectrometry as well as proximity ligation assay. A macromolecular complex composed of Cav1.3, HCN, and SK3 channels was unraveled. In addition, novel potential interactions between SK3 channels and sclerosis tuberous complex (Tsc) proteins, inhibitors of mTOR, and between HCN4 channels and the pro-degenerative protein Sarm1 were uncovered. In order to demonstrate the presence of these molecular interactions in situ, we used proximity ligation assay (PLA) imaging on midbrain slices containing the substantia nigra, and we could ascertain the presence of these protein complexes specifically in substantia nigra dopaminergic neurons. Based on the complementary functional role of the ion channels in the macromolecular complex identified, these results suggest that such tight interactions could partly underly the robustness of pacemaking in dopaminergic neurons.
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Affiliation(s)
- Maya Belghazi
- CRN2M Centre de Recherche Neurobiologie-Neurophysiologie, CNRS, UMR7286, Aix-Marseille Université, 13015 Marseille, France;
- Institut de Microbiologie de la Méditerranée (IMM), CNRS, Aix-Marseille Université, 13009 Marseille, France
| | - Cécile Iborra
- Ion Channel and Synaptic Neurobiology, INSERM, UMR1072, Aix-Marseille Université, 13015 Marseille, France; (C.I.); (O.T.); (M.L.); (D.D.); (J.-M.G.)
| | - Ophélie Toutendji
- Ion Channel and Synaptic Neurobiology, INSERM, UMR1072, Aix-Marseille Université, 13015 Marseille, France; (C.I.); (O.T.); (M.L.); (D.D.); (J.-M.G.)
| | - Manon Lasserre
- Ion Channel and Synaptic Neurobiology, INSERM, UMR1072, Aix-Marseille Université, 13015 Marseille, France; (C.I.); (O.T.); (M.L.); (D.D.); (J.-M.G.)
| | - Dominique Debanne
- Ion Channel and Synaptic Neurobiology, INSERM, UMR1072, Aix-Marseille Université, 13015 Marseille, France; (C.I.); (O.T.); (M.L.); (D.D.); (J.-M.G.)
| | - Jean-Marc Goaillard
- Ion Channel and Synaptic Neurobiology, INSERM, UMR1072, Aix-Marseille Université, 13015 Marseille, France; (C.I.); (O.T.); (M.L.); (D.D.); (J.-M.G.)
- Institut de Neurosciences de la Timone, CNRS, Aix-Marseille Université, 13005 Marseille, France
| | - Béatrice Marquèze-Pouey
- Ion Channel and Synaptic Neurobiology, INSERM, UMR1072, Aix-Marseille Université, 13015 Marseille, France; (C.I.); (O.T.); (M.L.); (D.D.); (J.-M.G.)
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2
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Ray S, Gurung P, Manning RS, Kravchuk AA, Singhvi A. Neuron cilia restrain glial KCC-3 to a microdomain to regulate multisensory processing. Cell Rep 2024; 43:113844. [PMID: 38421867 DOI: 10.1016/j.celrep.2024.113844] [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: 09/12/2023] [Revised: 12/15/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Glia interact with multiple neurons, but it is unclear whether their interactions with each neuron are different. Our interrogation at single-cell resolution reveals that a single glial cell exhibits specificity in its interactions with different contacting neurons. Briefly, C. elegans amphid sheath (AMsh) glia apical-like domains contact 12 neuron-endings. At these ad-neuronal membranes, AMsh glia localize the K/Cl transporter KCC-3 to a microdomain exclusively around the thermosensory AFD neuron to regulate its properties. Glial KCC-3 is transported to ad-neuronal regions, where distal cilia of non-AFD glia-associated chemosensory neurons constrain it to a microdomain at AFD-contacting glial membranes. Aberrant KCC-3 localization impacts both thermosensory (AFD) and chemosensory (non-AFD) neuron properties. Thus, neurons can interact non-synaptically through a shared glial cell by regulating microdomain localization of its cues. As AMsh and glia across species compartmentalize multiple cues like KCC-3, we posit that this may be a broadly conserved glial mechanism that modulates information processing across multimodal circuits.
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Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Pralaksha Gurung
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - R Sean Manning
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Alexandra A Kravchuk
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
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3
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Bai PH, Yu JP, Hu RR, Fu QW, Wu HC, Li XY, Zu GH, Liu BS, Zhang Y. Behavioral and molecular response of the insect parasitic nematode Steinernema carpocapsae to plant volatiles. J Invertebr Pathol 2024; 203:108067. [PMID: 38278342 DOI: 10.1016/j.jip.2024.108067] [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: 05/19/2023] [Revised: 10/31/2023] [Accepted: 01/22/2024] [Indexed: 01/28/2024]
Abstract
Entomopathogenic nematodes (EPNs) use the chemical cues emitted by insects and insect-damaged plants to locate their hosts. Steinernema carpocapsae, a species of EPN, is an established biocontrol agent used against insect pests. Despite its promising potential, the molecular mechanisms underlying its ability to detect plant volatiles remain poorly understood. In this study, we investigated the response of S. carpocapsae infective juveniles (IJs) to 8 different plant volatiles. Among these, carvone was found to be the most attractive volatile compound. To understand the molecular basis of the response of IJs to carvone, we used RNA-Seq technology to identify gene expression changes in response to carvone treatment. Transcriptome analysis revealed 721 differentially expressed genes (DEGs) between carvone-treated and control groups, with 403 genes being significantly upregulated and 318 genes downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the responsive DEGs to carvone attraction were mainly involved in locomotion, localization, behavior, response to stimulus, and olfactory transduction. We also identified four upregulated genes of chemoreceptor and response to stimulus that were involved in the response of IJs to carvone attraction. Our results provide insights into the potential transcriptional mechanisms underlying the response of S. carpocapsae to carvone, which can be utilized to develop environmentally friendly strategies for attracting EPNs.
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Affiliation(s)
- Peng-Hua Bai
- Institute of Plant Protection, Tianjin Academy of Agricultural Sciences, Tianjin 300384, PR China
| | - Jin-Ping Yu
- Institute of Plant Protection, Tianjin Academy of Agricultural Sciences, Tianjin 300384, PR China
| | - Rui-Rui Hu
- Institute of Plant Protection, Tianjin Academy of Agricultural Sciences, Tianjin 300384, PR China
| | - Qian-Wen Fu
- College of Horticulture and Landscape, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Hai-Chao Wu
- College of Horticulture and Landscape, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Xing-Yue Li
- Institute of Plant Protection, Sichuan Academy of Agricultural Sciences, Chengdu 610066, PR China
| | - Guo-Hao Zu
- College of Horticulture and Landscape, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Bao-Sheng Liu
- Institute of Plant Protection, Tianjin Academy of Agricultural Sciences, Tianjin 300384, PR China.
| | - Yu Zhang
- Key Laboratory of Biohazard Monitoring, Green Prevention and Control for Artificial Grassland, Ministry of Agriculture and Rural Affairs, Institute of Grassland Research of Chinese Academy of Agricultural Sciences, Inner Mongolia, Hohhot 010010, PR China.
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4
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Lin C, Shan Y, Wang Z, Peng H, Li R, Wang P, He J, Shen W, Wu Z, Guo M. Molecular and circuit mechanisms underlying avoidance of rapid cooling stimuli in C. elegans. Nat Commun 2024; 15:297. [PMID: 38182628 PMCID: PMC10770330 DOI: 10.1038/s41467-023-44638-5] [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: 03/12/2023] [Accepted: 12/21/2023] [Indexed: 01/07/2024] Open
Abstract
The mechanisms by which animals respond to rapid changes in temperature are largely unknown. Here, we found that polymodal ASH sensory neurons mediate rapid cooling-evoked avoidance behavior within the physiological temperature range in C. elegans. ASH employs multiple parallel circuits that consist of stimulatory circuits (AIZ, RIA, AVA) and disinhibitory circuits (AIB, RIM) to respond to rapid cooling. In the stimulatory circuit, AIZ, which is activated by ASH, releases glutamate to act on both GLR-3 and GLR-6 receptors in RIA neurons to promote reversal, and ASH also directly or indirectly stimulates AVA to promote reversal. In the disinhibitory circuit, AIB is stimulated by ASH through the GLR-1 receptor, releasing glutamate to act on AVR-14 to suppress RIM activity. RIM, an inter/motor neuron, inhibits rapid cooling-evoked reversal, and the loop activities thus equally stimulate reversal. Our findings elucidate the molecular and circuit mechanisms underlying the acute temperature stimuli-evoked avoidance behavior.
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Affiliation(s)
- Chenxi Lin
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuxin Shan
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhongyi Wang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hui Peng
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Rong Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Pingzhou Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Junyan He
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Weiwei Shen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Zhengxing Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Min Guo
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China.
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5
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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.
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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
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6
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Sun Y, Jin Y. An intraflagellar transport dependent negative feedback regulates the MAPKKK DLK-1 to protect cilia from degeneration. Proc Natl Acad Sci U S A 2023; 120:e2302801120. [PMID: 37722038 PMCID: PMC10523469 DOI: 10.1073/pnas.2302801120] [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: 02/20/2023] [Accepted: 08/15/2023] [Indexed: 09/20/2023] Open
Abstract
Primary cilia are specialized organelles supporting the development and function of cells and organisms. Intraflagellar transport (IFT) is essential for cilia formation, maintenance, and function. In C. elegans ciliated sensory neurons, IFT interacts with signaling molecules to generate distinct morphological and function features and also to maintain the integrity of cilia. Here, we report an IFT-dependent feedback control on the conserved MAPKKK DLK-1 in the ciliated sensory neurons. DLK proteins are widely known to act in synapse formation, axon regeneration, and degeneration, but their roles in other neuronal compartments are understudied. By forward genetic screening for altered expression of the endogenously tagged DLK-1 we identified multiple ift mutants showing increased DLK-1 accumulation in the defective sensory endings. We show that in response to acute IFT disruption, DLK-1 accumulates rapidly and reversibly. The expression levels of the transcription factor CEBP-1, known to act downstream of DLK-1 in the development and maintenance of synapses and axons, are also increased in the ciliated sensory neurons of ift mutants. Interestingly, the regulation of CEBP-1 expression shows sensory neuron-type dependency on DLK-1. Moreover, in the sensory neuron AWC, which has elaborate cilia morphology, up-regulated CEBP-1 represses DLK-1 at the transcription level, thereby dampening DLK-1 accumulation. Last, the IFT-dependent regulatory loop of DLK-1 and CEBP-1 offers neuroprotection in a cilia degeneration model. These findings uncover a surveillance mechanism in which tight control on the DLK-1 signaling protects cilia integrity in a context-specific manner.
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Affiliation(s)
- Yue Sun
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA92093
| | - Yishi Jin
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA92093
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7
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Chandra R, Farah F, Muñoz-Lobato F, Bokka A, Benedetti KL, Brueggemann C, Saifuddin MFA, Miller JM, Li J, Chang E, Varshney A, Jimenez V, Baradwaj A, Nassif C, Alladin S, Andersen K, Garcia AJ, Bi V, Nordquist SK, Dunn RL, Garcia V, Tokalenko K, Soohoo E, Briseno F, Kaur S, Harris M, Guillen H, Byrd D, Fung B, Bykov AE, Odisho E, Tsujimoto B, Tran A, Duong A, Daigle KC, Paisner R, Zuazo CE, Lin C, Asundi A, Churgin MA, Fang-Yen C, Bremer M, Kato S, VanHoven MK, L'Étoile ND. Sleep is required to consolidate odor memory and remodel olfactory synapses. Cell 2023; 186:2911-2928.e20. [PMID: 37269832 PMCID: PMC10354834 DOI: 10.1016/j.cell.2023.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 02/02/2023] [Accepted: 05/05/2023] [Indexed: 06/05/2023]
Abstract
Animals with complex nervous systems demand sleep for memory consolidation and synaptic remodeling. Here, we show that, although the Caenorhabditis elegans nervous system has a limited number of neurons, sleep is necessary for both processes. In addition, it is unclear if, in any system, sleep collaborates with experience to alter synapses between specific neurons and whether this ultimately affects behavior. C. elegans neurons have defined connections and well-described contributions to behavior. We show that spaced odor-training and post-training sleep induce long-term memory. Memory consolidation, but not acquisition, requires a pair of interneurons, the AIYs, which play a role in odor-seeking behavior. In worms that consolidate memory, both sleep and odor conditioning are required to diminish inhibitory synaptic connections between the AWC chemosensory neurons and the AIYs. Thus, we demonstrate in a living organism that sleep is required for events immediately after training that drive memory consolidation and alter synaptic structures.
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Affiliation(s)
- Rashmi Chandra
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Fatima Farah
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Fernando Muñoz-Lobato
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Anirudh Bokka
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kelli L Benedetti
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Chantal Brueggemann
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Mashel Fatema A Saifuddin
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Julia M Miller
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Joy Li
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Eric Chang
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Aruna Varshney
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Vanessa Jimenez
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Anjana Baradwaj
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Cibelle Nassif
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Sara Alladin
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kristine Andersen
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Angel J Garcia
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Veronica Bi
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Sarah K Nordquist
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Raymond L Dunn
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Vanessa Garcia
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kateryna Tokalenko
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Emily Soohoo
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Fabiola Briseno
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Sukhdeep Kaur
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Malcolm Harris
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Hazel Guillen
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Decklin Byrd
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Brandon Fung
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Andrew E Bykov
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Emma Odisho
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Bryan Tsujimoto
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Alan Tran
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Alex Duong
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kevin C Daigle
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Rebekka Paisner
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Carlos E Zuazo
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Christine Lin
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Aarati Asundi
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Matthew A Churgin
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Martina Bremer
- Department of Mathematics and Statistics, San José State University, San José, CA 95192, USA
| | - Saul Kato
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Miri K VanHoven
- Department of Biological Sciences, San José State University, San José, CA 95192, USA.
| | - Noëlle D L'Étoile
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA.
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8
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Davis K, Mitchell C, Weissenfels O, Bai J, Raizen DM, Ailion M, Topalidou I. G protein-coupled receptor kinase-2 (GRK-2) controls exploration through neuropeptide signaling in Caenorhabditis elegans. PLoS Genet 2023; 19:e1010613. [PMID: 36652499 PMCID: PMC9886303 DOI: 10.1371/journal.pgen.1010613] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/30/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023] Open
Abstract
Animals alter their behavior in manners that depend on environmental conditions as well as their developmental and metabolic states. For example, C. elegans is quiescent during larval molts or during conditions of satiety. By contrast, worms enter an exploration state when removed from food. Sensory perception influences movement quiescence (defined as a lack of body movement), as well as the expression of additional locomotor states in C. elegans that are associated with increased or reduced locomotion activity, such as roaming (exploration behavior) and dwelling (local search). Here we find that movement quiescence is enhanced, and exploration behavior is reduced in G protein-coupled receptor kinase grk-2 mutant animals. grk-2 was previously shown to act in chemosensation, locomotion, and egg-laying behaviors. Using neuron-specific rescuing experiments, we show that GRK-2 acts in multiple ciliated chemosensory neurons to control exploration behavior. grk-2 acts in opposite ways from the cGMP-dependent protein kinase gene egl-4 to control movement quiescence and exploration behavior. Analysis of mutants with defects in ciliated sensory neurons indicates that grk-2 and the cilium-structure mutants act in the same pathway to control exploration behavior. We find that GRK-2 controls exploration behavior in an opposite manner from the neuropeptide receptor NPR-1 and the neuropeptides FLP-1 and FLP-18. Finally, we show that secretion of the FLP-1 neuropeptide is negatively regulated by GRK-2 and that overexpression of FLP-1 reduces exploration behavior. These results define neurons and molecular pathways that modulate movement quiescence and exploration behavior.
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Affiliation(s)
- Kristen Davis
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Center for Excellence in Environmental Toxicology (CEET), Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Christo Mitchell
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Olivia Weissenfels
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Jihong Bai
- Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - David M. Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
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9
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Nicoletti M, Luchetti N, Chiodo L, Loppini A, Folli V, Ruocco G, Filippi S. Modeling of olfactory transduction in AWC ON neuron via coupled electrical-calcium dynamics. Biomol Concepts 2023; 14:bmc-2022-0035. [PMID: 37574865 DOI: 10.1515/bmc-2022-0035] [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: 06/20/2023] [Accepted: 07/28/2023] [Indexed: 08/15/2023] Open
Abstract
Amphid wing "C" (AWC) neurons are among the most important and studied neurons of the nematode Caenorhabditis elegans. In this work, we unify the existing electrical and intracellular calcium dynamics descriptions to obtain a biophysically accurate model of olfactory transduction in AWCON neurons. We study the membrane voltage and the intracellular calcium dynamics at different exposure times and odorant concentrations to grasp a complete picture of AWCON functioning. Moreover, we investigate the complex cascade of biochemical processes that allow AWC activation upon odor removal. We analyze the behavior of the different components of the models and, by suppressing them selectively, we extrapolate their contribution to the overall neuron response and study the resilience of the dynamical system. Our results are all in agreement with the available experimental data. Therefore, we provide an accurate mathematical and biophysical model for studying olfactory signal processing in C. elegans.
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Affiliation(s)
- Martina Nicoletti
- Department of Engineering, Campus Bio-Medico University, Rome, Italy
- Center for Life Nano- & Neuro-Science (CLN2S@Sapienza), Italian Institute of Technology, Rome, Italy
| | - Nicole Luchetti
- Department of Engineering, Campus Bio-Medico University, Rome, Italy
- Center for Life Nano- & Neuro-Science (CLN2S@Sapienza), Italian Institute of Technology, Rome, Italy
| | - Letizia Chiodo
- Department of Engineering, Campus Bio-Medico University, Rome, Italy
| | | | - Viola Folli
- Center for Life Nano- & Neuro-Science (CLN2S@Sapienza), Italian Institute of Technology, Rome, Italy
- D-tails s.r.l., Via di Torre Rossa 66, 00165, Rome, Italy
| | - Giancarlo Ruocco
- Center for Life Nano- & Neuro-Science (CLN2S@Sapienza), Italian Institute of Technology, Rome, Italy
| | - Simonetta Filippi
- Department of Engineering, Campus Bio-Medico University, Rome, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Florence, Italy
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10
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Segref A, Vakkayil KL, Padvitski T, Li Q, Kroef V, Lormann J, Körner L, Finger F, Hoppe T. Thermosensation in Caenorhabditis elegans is linked to ubiquitin-dependent protein turnover via insulin and calcineurin signalling. Nat Commun 2022; 13:5874. [PMID: 36198694 PMCID: PMC9534930 DOI: 10.1038/s41467-022-33467-7] [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: 12/10/2021] [Accepted: 09/16/2022] [Indexed: 11/21/2022] Open
Abstract
Organismal physiology and survival are influenced by environmental conditions and linked to protein quality control. Proteome integrity is achieved by maintaining an intricate balance between protein folding and degradation. In Caenorhabditis elegans, acute heat stress determines cell non-autonomous regulation of chaperone levels. However, how the perception of environmental changes, including physiological temperature, affects protein degradation remains largely unexplored. Here, we show that loss-of-function of dyf-1 in Caenorhabditis elegans associated with dysfunctional sensory neurons leads to defects in both temperature perception and thermal adaptation of the ubiquitin/proteasome system centered on thermosensory AFD neurons. Impaired perception of moderate temperature changes worsens ubiquitin-dependent proteolysis in intestinal cells. Brain-gut communication regulating protein turnover is mediated by upregulation of the insulin-like peptide INS-5 and inhibition of the calcineurin-regulated forkhead-box transcription factor DAF-16/FOXO. Our data indicate that perception of ambient temperature and its neuronal integration is important for the control of proteome integrity in complex organisms.
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Affiliation(s)
- Alexandra Segref
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany.
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.
| | - Kavya L Vakkayil
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
| | - Tsimafei Padvitski
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
| | - Qiaochu Li
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
| | - Virginia Kroef
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
- Max Planck Institute for Biology of Ageing, 50931, Cologne, Germany
| | - Jakob Lormann
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
| | - Lioba Körner
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
| | - Fabian Finger
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Thorsten Hoppe
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany.
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital of Cologne, 50931, Cologne, Germany.
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11
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Xiong R, Hsieh YW, Chuang CF. CEPsh glia development is not required for general AWC identity or AWC asymmetry. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000636. [PMID: 36188097 PMCID: PMC9523477 DOI: 10.17912/micropub.biology.000636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/30/2022] [Accepted: 09/13/2022] [Indexed: 11/06/2022]
Abstract
The Caenorhabditis elegans VAB-3/Pax6 homeodomain protein was previously shown to play a role in both the development of cephalic sheath (CEPsh) glia and asymmetric differentiation of AWC olfactory neuron subtypes AWC ON /AWC OFF . Here we show that vab-3 is not required for the specification of general AWC identity. We also show that some vab-3 mutant alleles with defective CEPsh glia development displayed wild-type AWC asymmetry. These results suggest that vab-3 has separable roles in CEPsh glia development and AWC asymmetry. Together, our results suggest that general AWC identity and AWC asymmetry are not dependent on the development of CEPsh glia.
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Affiliation(s)
- Rui Xiong
- Department of Biological Sciences, University of Illinois at Chicago, IL, USA
| | - Yi-Wen Hsieh
- Department of Biological Sciences, University of Illinois at Chicago, IL, USA
| | - Chiou-Fen Chuang
- Department of Biological Sciences, University of Illinois at Chicago, IL, USA
,
Graduate Program in Neuroscience, University of Illinois at Chicago, IL, USA
,
Correspondence to: Chiou-Fen Chuang (
)
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12
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Yu B, Wang Y, Gao S. Motor Rhythm Dissection From the Backward Circuit in C. elegans. Front Mol Neurosci 2022; 15:845733. [PMID: 35370545 PMCID: PMC8966088 DOI: 10.3389/fnmol.2022.845733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 01/26/2022] [Indexed: 11/28/2022] Open
Abstract
Motor rhythm is initiated and sustained by oscillatory neuronal activity. We recently discovered that the A-class excitatory motor neurons (MNs) (A-MNs) function as intrinsic oscillators. They drive backward locomotion by generating rhythmic postsynaptic currents (rPSCs) in body wall muscles. Molecular underpinning of the rPSCs, however, is not fully elucidated. We report here that there are three types of the rPSC patterns, namely the phasic, tonic, and long-lasting, each with distinct kinetics and channel-dependence. The Na+ leak channel is required for all rPSC patterns. The tonic rPSCs exhibit strong dependence on the high-voltage-gated Ca2+ channels. Three K+ channels, the BK-type Ca2+-activated K+ channel, Na+-activated K+ channel, and voltage-gated K+ channel (Kv4), primarily inhibit tonic and long-lasting rPSCs with varying degrees and preferences. The elaborate regulation of rPSCs by different channels, through increasing or decreasing the rPSCs frequency and/or charge, correlates with the changes in the reversal velocity for respective channel mutants. The molecular dissection of different A-MNs-rPSC components therefore reveals different mechanisms for multiplex motor rhythm.
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Affiliation(s)
- Bin Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Ya Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
- Department of Geriatrics, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Shangbang Gao,
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13
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Heckman EL, Doe CQ. Presynaptic contact and activity opposingly regulate postsynaptic dendrite outgrowth. eLife 2022; 11:82093. [PMID: 36448675 PMCID: PMC9728994 DOI: 10.7554/elife.82093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
The organization of neural circuits determines nervous system function. Variability can arise during neural circuit development (e.g. neurite morphology, axon/dendrite position). To ensure robust nervous system function, mechanisms must exist to accommodate variation in neurite positioning during circuit formation. Previously, we developed a model system in the Drosophila ventral nerve cord to conditionally induce positional variability of a proprioceptive sensory axon terminal, and used this model to show that when we altered the presynaptic position of the sensory neuron, its major postsynaptic interneuron partner modified its dendritic arbor to match the presynaptic contact, resulting in functional synaptic input (Sales et al., 2019). Here, we investigate the cellular mechanisms by which the interneuron dendrites detect and match variation in presynaptic partner location and input strength. We manipulate the presynaptic sensory neuron by (a) ablation; (b) silencing or activation; or (c) altering its location in the neuropil. From these experiments we conclude that there are two opposing mechanisms used to establish functional connectivity in the face of presynaptic variability: presynaptic contact stimulates dendrite outgrowth locally, whereas presynaptic activity inhibits postsynaptic dendrite outgrowth globally. These mechanisms are only active during an early larval critical period for structural plasticity. Collectively, our data provide new insights into dendrite development, identifying mechanisms that allow dendrites to flexibly respond to developmental variability in presynaptic location and input strength.
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Affiliation(s)
- Emily L Heckman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of OregonEugeneUnited States
| | - Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of OregonEugeneUnited States
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14
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A single chemosensory GPCR is required for a concentration-dependent behavioral switching in C. elegans. Curr Biol 2021; 32:398-411.e4. [PMID: 34906353 DOI: 10.1016/j.cub.2021.11.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 10/15/2021] [Accepted: 11/12/2021] [Indexed: 12/19/2022]
Abstract
Animals detect and discriminate countless environmental chemicals for their well-being and survival. Although a single chemical can trigger opposing behavioral responses depending on its concentration, the mechanisms underlying such a concentration-dependent switching remain poorly understood. Here, we show that C. elegans exhibits either attraction or avoidance of the bacteria-derived volatile chemical dimethyl trisulfide (DMTS) depending on its concentration. This behavioral switching is mediated by two different types of chemosensory neurons, both of which express the DMTS-sensitive seven-transmembrane G protein-coupled receptor (GPCR) SRI-14. These two sensory neurons share downstream interneurons that process and translate DMTS signals via distinct glutamate receptors to generate the appropriate behavioral outcome. Thus, our results present one mechanism by which an animal connects two distinct types of chemosensory neurons detecting a common ligand to alternate downstream circuitry, thus efficiently switching between specific behavioral programs based on ligand concentration.
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15
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Hsieh YW, Xiong R, Chuang CF. Synergistic roles of homeodomain proteins UNC-62 homothorax and MLS-2 HMX/NKX in the specification of olfactory neurons in Caenorhabditis elegans. Genetics 2021; 219:6350488. [PMID: 34849889 DOI: 10.1093/genetics/iyab133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 08/09/2021] [Indexed: 11/13/2022] Open
Abstract
General identity of the Caenorhabditis elegans AWC olfactory neuron pair is specified by the OTX/OTD transcription factor CEH-36 and the HMG-box transcription factor SOX-2, followed by asymmetrical differentiation of the pair into two distinct subtypes, default AWCOFF and induced AWCON, through a stochastic signaling event. The HMX/NKX transcription factor MLS-2 regulates the expression of ceh-36 to specify general AWC identity. However, general AWC identity is lost in only one of the two AWC cells in the majority of mls-2 null mutants displaying defective general AWC identity, suggesting that additional transcription factors have a partially overlapping role with MLS-2 in the specification of general AWC identity. Here, we identify a role of unc-62, encoding a homothorax/Meis/TALE homeodomain protein, in the specification of general AWC identity. As in mls-2 null mutants, unc-62 null mutants showed an incomplete penetrance in loss of general AWC identity. However, unc-62; mls-2 double mutants display a nearly complete penetrance of identity loss in both AWC cells. Thus, unc-62 and mls-2 have a partially overlapping function in the specification of general AWC identity. Furthermore, our genetic results suggest that mls-2 and unc-62 act cell autonomously in promoting the AWCON subtype. Together, our findings reveal the sequential roles of the unc-62 and mls-2 pair in AWC development, specification of general AWC identity in early embryogenesis, and asymmetric differentiation of AWC subtypes in late embryogenesis.
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Affiliation(s)
- Yi-Wen Hsieh
- Department of Biological Sciences, University of Illinois at Chicago, IL 60607, USA
| | - Rui Xiong
- Department of Biological Sciences, University of Illinois at Chicago, IL 60607, USA
| | - Chiou-Fen Chuang
- Department of Biological Sciences, University of Illinois at Chicago, IL 60607, USA.,Graduate Program in Neuroscience, University of Illinois at Chicago, IL 60607, USA
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16
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Cavelius M, Brunel T, Didier A. Lessons from behavioral lateralization in olfaction. Brain Struct Funct 2021; 227:685-696. [PMID: 34596756 PMCID: PMC8843900 DOI: 10.1007/s00429-021-02390-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/19/2021] [Indexed: 11/16/2022]
Abstract
Sensory information, sampled by sensory organs positioned on each side of the body may play a crucial role in organizing brain lateralization. This question is of particular interest with regard to the growing evidence of alteration in lateralization in several psychiatric conditions. In this context, the olfactory system, an ancient, mostly ipsilateral and well-conserved system across phylogeny may prove an interesting model system to understand the behavioral significance of brain lateralization. Here, we focused on behavioral data in vertebrates and non-vertebrates, suggesting that the two hemispheres of the brain differentially processed olfactory cues to achieve diverse sensory operations, such as detection, discrimination, identification of behavioral valuable cues or learning. These include reports across different species on best performances with one nostril or the other or odorant active sampling by one nostril or the other, depending on odorants or contexts. In some species, hints from peripheral anatomical or functional asymmetry were proposed to explain these asymmetries in behavior. Instigations of brain activation or more rarely of brain connectivity evoked by odorants revealed a complex picture with regards to asymmetric patterns which is discussed with respect to behavioral data. Along the steps of the discussed literature, we propose avenues for future research.
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Affiliation(s)
- Matthias Cavelius
- Lyon Neuroscience Research Center (CRNL), Neuropop Team, Lyon, France.,CNRS 5292, Inserm 1028, Lyon 1 University, Lyon, France
| | - Théo Brunel
- Lyon Neuroscience Research Center (CRNL), Neuropop Team, Lyon, France.,CNRS 5292, Inserm 1028, Lyon 1 University, Lyon, France
| | - Anne Didier
- Lyon Neuroscience Research Center (CRNL), Neuropop Team, Lyon, France. .,CNRS 5292, Inserm 1028, Lyon 1 University, Lyon, France.
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17
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Davis L, Radman I, Goutou A, Tynan A, Baxter K, Xi Z, O'Shea JM, Chin JW, Greiss S. Precise optical control of gene expression in C. elegans using improved genetic code expansion and Cre recombinase. eLife 2021; 10:67075. [PMID: 34350826 PMCID: PMC8448529 DOI: 10.7554/elife.67075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 08/04/2021] [Indexed: 11/13/2022] Open
Abstract
Synthetic strategies for optically controlling gene expression may enable the precise spatiotemporal control of genes in any combination of cells that cannot be targeted with specific promoters. We develop an improved genetic code expansion system in Caenorhabditis elegans and use it to create a photoactivatable Cre recombinase. We laser-activate Cre in single neurons within a bilaterally symmetric pair to selectively switch on expression of a loxP-controlled optogenetic channel in the targeted neuron. We use the system to dissect, in freely moving animals, the individual contributions of the mechanosensory neurons PLML/PLMR to the C. elegans touch response circuit, revealing distinct and synergistic roles for these neurons. We thus demonstrate how genetic code expansion and optical targeting can be combined to break the symmetry of neuron pairs and dissect behavioural outputs of individual neurons that cannot be genetically targeted. Animal behaviour and movement emerges from the stimulation of nerve cells that are connected together like a circuit. Researchers use various tools to investigate these neural networks in model organisms such as roundworms, fruit flies and zebrafish. The trick is to activate some nerve cells, but not others, so as to isolate their specific role within the neural circuit. One way to do this is to switch genes on or off in individual cells as a way to control their neuronal activity. This can be achieved by building a photocaged version of the enzyme Cre recombinase which is designed to target specific genes. The modified Cre recombinase contains an amino acid (the building blocks of proteins) that inactivates the enzyme. When the cell is illuminated with UV light, a part of the amino acid gets removed allowing Cre recombinase to turn on its target gene. However, cells do not naturally produce these photocaged amino acids. To overcome this, researchers can use a technology called genetic code expansion which provides cells with the tools they need to build proteins containing these synthetic amino acids. Although this technique has been used in live animals, its application has been limited due to the small amount of proteins it produces. Davis et al. therefore set out to improve the efficiency of genetic code expansion so that it can be used to study single nerve cells in freely moving roundworms. In the new system, named LaserTAC, individual cells are targeted with UV light that ‘uncages’ the Cre recombinase enzyme so it can switch on a gene for a protein that controls neuronal activity. Davis et al. used this approach to stimulate a pair of neurons sensitive to touch to see how this impacted the roundworm’s behaviour. This revealed that individual neurons within this pair contribute to the touch response in different ways. However, input from both neurons is required to produce a robust reaction. These findings show that the LaserTAC system can be used to manipulate gene activity in single cells, such as neurons, using light. It allows researchers to precisely control in which cells and when a given gene is switched on or off. Also, with the improved efficiency of the genetic code expansion, this technology could be used to modify proteins other than Cre recombinase and be applied to other artificial amino acids that have been developed in recent years.
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Affiliation(s)
- Lloyd Davis
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Inja Radman
- Protein and Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Angeliki Goutou
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Ailish Tynan
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Kieran Baxter
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Zhiyan Xi
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jack M O'Shea
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Sebastian Greiss
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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18
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Rapti G. A perspective on C. elegans neurodevelopment: from early visionaries to a booming neuroscience research. J Neurogenet 2021; 34:259-272. [PMID: 33446023 DOI: 10.1080/01677063.2020.1837799] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The formation of the nervous system and its striking complexity is a remarkable feat of development. C. elegans served as a unique model to dissect the molecular events in neurodevelopment, from its early visionaries to the current booming neuroscience community. Soon after being introduced as a model, C. elegans was mapped at the level of genes, cells, and synapses, providing the first metazoan with a complete cell lineage, sequenced genome, and connectome. Here, I summarize mechanisms underlying C. elegans neurodevelopment, from the generation and diversification of neural components to their navigation and connectivity. I point out recent noteworthy findings in the fields of glia biology, sex dimorphism and plasticity in neurodevelopment, highlighting how current research connects back to the pioneering studies by Brenner, Sulston and colleagues. Multifaceted investigations in model organisms, connecting genes to cell function and behavior, expand our mechanistic understanding of neurodevelopment while allowing us to formulate emerging questions for future discoveries.
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Affiliation(s)
- Georgia Rapti
- European Molecular Biology Laboratory, Unit of Developmental Biology, Heidelberg, Germany
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19
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Taylor SR, Santpere G, Weinreb A, Barrett A, Reilly MB, Xu C, Varol E, Oikonomou P, Glenwinkel L, McWhirter R, Poff A, Basavaraju M, Rafi I, Yemini E, Cook SJ, Abrams A, Vidal B, Cros C, Tavazoie S, Sestan N, Hammarlund M, Hobert O, Miller DM. Molecular topography of an entire nervous system. Cell 2021; 184:4329-4347.e23. [PMID: 34237253 DOI: 10.1016/j.cell.2021.06.023] [Citation(s) in RCA: 247] [Impact Index Per Article: 82.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/09/2021] [Accepted: 06/14/2021] [Indexed: 02/08/2023]
Abstract
We have produced gene expression profiles of all 302 neurons of the C. elegans nervous system that match the single-cell resolution of its anatomy and wiring diagram. Our results suggest that individual neuron classes can be solely identified by combinatorial expression of specific gene families. For example, each neuron class expresses distinct codes of ∼23 neuropeptide genes and ∼36 neuropeptide receptors, delineating a complex and expansive "wireless" signaling network. To demonstrate the utility of this comprehensive gene expression catalog, we used computational approaches to (1) identify cis-regulatory elements for neuron-specific gene expression and (2) reveal adhesion proteins with potential roles in process placement and synaptic specificity. Our expression data are available at https://cengen.org and can be interrogated at the web application CengenApp. We expect that this neuron-specific directory of gene expression will spur investigations of underlying mechanisms that define anatomy, connectivity, and function throughout the C. elegans nervous system.
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Affiliation(s)
- Seth R Taylor
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Gabriel Santpere
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Neurogenomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), DCEXS, Universitat Pompeu Fabra, 08003 Barcelona, Catalonia, Spain
| | - Alexis Weinreb
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Alec Barrett
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Molly B Reilly
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Chuan Xu
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Erdem Varol
- Department of Statistics, Columbia University, New York, NY, USA
| | - Panos Oikonomou
- Department of Biological Sciences, Columbia University, New York, NY, USA; Department of Systems Biology, Columbia University Medical Center, New York, NY, USA
| | - Lori Glenwinkel
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Rebecca McWhirter
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Abigail Poff
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Manasa Basavaraju
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Ibnul Rafi
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Eviatar Yemini
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Steven J Cook
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Alexander Abrams
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Berta Vidal
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Cyril Cros
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Saeed Tavazoie
- Department of Biological Sciences, Columbia University, New York, NY, USA; Department of Systems Biology, Columbia University Medical Center, New York, NY, USA
| | - Nenad Sestan
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Marc Hammarlund
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA.
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Program in Neuroscience, Vanderbilt University School of Medicine, Nashville, TN, USA.
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20
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Hino T, Hirai S, Ishihara T, Fujiwara M. EGL-4/PKG regulates the role of an interneuron in a chemotaxis circuit of C. elegans through mediating integration of sensory signals. Genes Cells 2021; 26:411-425. [PMID: 33817914 DOI: 10.1111/gtc.12849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 11/30/2022]
Abstract
Interneurons, innervated by multiple sensory neurons, need to integrate information from these sensory neurons and respond to sensory stimuli adequately. Mechanisms how sensory information is integrated to form responses of interneurons are not fully understood. In Caenorhabditis elegans, loss-of-function mutations of egl-4, which encodes a cGMP-dependent protein kinase (PKG), cause a defect in chemotaxis to odorants. Our genetic and imaging analyses revealed that the response property of AIY interneuron to an odorant is reversed in the egl-4 mutant, while the responses of two upstream olfactory neurons, AWA and AWC, are largely unchanged. Cell- ablation experiments show that AIY in the egl-4 mutant functions to suppress chemotaxis. Furthermore, the reversal of AIY response occurs only in the presence of sensory signals from both AWA and AWC. These results suggest that sensory signals are inadequately integrated in the egl-4 mutant. We also show that egl-4 expression in AWA and another sensory neuron prevents the reversed AIY response and restores chemotaxis in the egl-4 mutants. We propose that EGL-4/PKG, by suppressing aberrant integration of signals from olfactory neurons, converts the response property of an interneuron to olfactory stimuli and maintains the role of the interneuron in the circuit to execute chemotactic behavior.
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Affiliation(s)
- Takahiro Hino
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Shota Hirai
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Takeshi Ishihara
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Manabi Fujiwara
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
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21
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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.
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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
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22
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Hsu TY, Zhang B, L'Etoile ND, Juang BT. C. elegans orthologs MUT-7/CeWRN-1 of Werner syndrome protein regulate neuronal plasticity. eLife 2021; 10:62449. [PMID: 33646120 PMCID: PMC7946423 DOI: 10.7554/elife.62449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 02/26/2021] [Indexed: 12/28/2022] Open
Abstract
Caenorhabditis elegans expresses human Werner syndrome protein (WRN) orthologs as two distinct proteins: MUT-7, with a 3′−5′ exonuclease domain, and CeWRN-1, with helicase domains. How these domains cooperate remains unclear. Here, we demonstrate the different contributions of MUT-7 and CeWRN-1 to 22G small interfering RNA (siRNA) synthesis and the plasticity of neuronal signaling. MUT-7 acts specifically in the cytoplasm to promote siRNA biogenesis and in the nucleus to associate with CeWRN-1. The import of siRNA by the nuclear Argonaute NRDE-3 promotes the loading of the heterochromatin-binding protein HP1 homolog HPL-2 onto specific loci. This heterochromatin complex represses the gene expression of the guanylyl cyclase ODR-1 to direct olfactory plasticity in C. elegans. Our findings suggest that the exonuclease and helicase domains of human WRN may act in concert to promote RNA-dependent loading into a heterochromatin complex, and the failure of this entire process reduces plasticity in postmitotic neurons.
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Affiliation(s)
- Tsung-Yuan Hsu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Bo Zhang
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Noelle D L'Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Bi-Tzen Juang
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
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23
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Srivastava P, Kane A, Harrison C, Levin M. A Meta-Analysis of Bioelectric Data in Cancer, Embryogenesis, and Regeneration. Bioelectricity 2021; 3:42-67. [PMID: 34476377 DOI: 10.1089/bioe.2019.0034] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Developmental bioelectricity is the study of the endogenous role of bioelectrical signaling in all cell types. Resting potentials and other aspects of ionic cell physiology are known to be important regulatory parameters in embryogenesis, regeneration, and cancer. However, relevant quantitative measurement and genetic phenotyping data are distributed throughout wide-ranging literature, hampering experimental design and hypothesis generation. Here, we analyze published studies on bioelectrics and transcriptomic and genomic/phenotypic databases to provide a novel synthesis of what is known in three important aspects of bioelectrics research. First, we provide a comprehensive list of channelopathies-ion channel and pump gene mutations-in a range of important model systems with developmental patterning phenotypes, illustrating the breadth of channel types, tissues, and phyla (including man) in which bioelectric signaling is a critical endogenous aspect of embryogenesis. Second, we perform a novel bioinformatic analysis of transcriptomic data during regeneration in diverse taxa that reveals an electrogenic protein to be the one common factor specifically expressed in regeneration blastemas across Kingdoms. Finally, we analyze data on distinct Vmem signatures in normal and cancer cells, revealing a specific bioelectrical signature corresponding to some types of malignancies. These analyses shed light on fundamental questions in developmental bioelectricity and suggest new avenues for research in this exciting field.
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Affiliation(s)
- Pranjal Srivastava
- Rye High School, Rye, New York, USA; Current Affiliation: College of Chemistry, University of California, Berkeley, Berkeley, California, USA
| | - Anna Kane
- Department of Biology, Allen Discovery Center, Tufts University, Medford, Massachusetts, USA
| | - Christina Harrison
- Department of Biology, Allen Discovery Center, Tufts University, Medford, Massachusetts, USA
| | - Michael Levin
- Department of Biology, Allen Discovery Center, Tufts University, Medford, Massachusetts, USA
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24
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Rabinowitch I, Upadhyaya B, Pant A, Galski D, Kreines L, Bai J. Circumventing neural damage in a C. elegans chemosensory circuit using genetically engineered synapses. Cell Syst 2021; 12:263-271.e4. [PMID: 33472027 DOI: 10.1016/j.cels.2020.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/03/2020] [Accepted: 12/22/2020] [Indexed: 10/22/2022]
Abstract
Neuronal loss can considerably diminish neural circuit function, impairing normal behavior by disrupting information flow in the circuit. Here, we use genetically engineered electrical synapses to reroute the flow of information in a C. elegans damaged chemosensory circuit in order to restore organism behavior. We impaired chemotaxis by removing one pair of interneurons from the circuit then artificially coupled two other adjacent neuron pairs by ectopically expressing the gap junction protein, connexin, in them. This restored chemotaxis in the animals. We expected to observe linear and direct information flow between the connexin-coupled neurons in the recovered circuit but also revealed the formation of new potent left-right lateral electrical connections within the connexin-expressing neuron pairs. Our analysis suggests that these additional electrical synapses help restore circuit function by amplifying weakened neuronal signals in the damaged circuit in addition to emulating the wild-type circuit. A record of this paper's transparent peer review process is included in the Supplemental Information.
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Affiliation(s)
- Ithai Rabinowitch
- Department of Medical Neurobiology, IMRIC - Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112002, Israel.
| | - Bishal Upadhyaya
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Aaradhya Pant
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Dolev Galski
- Department of Medical Neurobiology, IMRIC - Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Lena Kreines
- Department of Medical Neurobiology, IMRIC - Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Jihong Bai
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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25
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Wang M, Witvliet D, Wu M, Kang L, Shao Z. Temperature regulates synaptic subcellular specificity mediated by inhibitory glutamate signaling. PLoS Genet 2021; 17:e1009295. [PMID: 33428618 PMCID: PMC7822552 DOI: 10.1371/journal.pgen.1009295] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 01/22/2021] [Accepted: 12/05/2020] [Indexed: 01/13/2023] Open
Abstract
Environmental factors such as temperature affect neuronal activity and development. However, it remains unknown whether and how they affect synaptic subcellular specificity. Here, using the nematode Caenorhabditis elegans AIY interneurons as a model, we found that high cultivation temperature robustly induces defects in synaptic subcellular specificity through glutamatergic neurotransmission. Furthermore, we determined that the functional glutamate is mainly released by the ASH sensory neurons and sensed by two conserved inhibitory glutamate-gated chloride channels GLC-3 and GLC-4 in AIY. Our work not only presents a novel neurotransmission-dependent mechanism underlying the synaptic subcellular specificity, but also provides a potential mechanistic insight into high-temperature-induced neurological defects.
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Affiliation(s)
- Mengqing Wang
- Department of Neurosurgery, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Daniel Witvliet
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Mengting Wu
- Department of Neurosurgery, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lijun Kang
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhiyong Shao
- Department of Neurosurgery, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
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26
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Miller AC, Urban EA, Lyons EL, Herman TG, Johnston RJ. Interdependent regulation of stereotyped and stochastic photoreceptor fates in the fly eye. Dev Biol 2020; 471:89-96. [PMID: 33333066 PMCID: PMC7856283 DOI: 10.1016/j.ydbio.2020.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 12/14/2022]
Abstract
Diversification of neuronal subtypes often requires stochastic gene regulatory mechanisms. How stochastically expressed transcription factors interact with other regulators in gene networks to specify cell fates is poorly understood. The random mosaic of color-detecting R7 photoreceptor subtypes in Drosophila is controlled by the stochastic on/off expression of the transcription factor Spineless (Ss). In SsON R7s, Ss induces expression of Rhodopsin 4 (Rh4), whereas in SsOFF R7s, the absence of Ss allows expression of Rhodopsin 3 (Rh3). Here, we find that the transcription factor Runt, which is initially expressed in all R7s, is sufficient to promote stochastic Ss expression. Later, as R7s develop, Ss negatively feeds back onto Runt to prevent repression of Rh4 and ensure proper fate specification. Together, stereotyped and stochastic regulatory inputs are integrated into feedforward and feedback mechanisms to control cell fate.
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Affiliation(s)
- Adam C Miller
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97403, USA
| | - Elizabeth A Urban
- Department of Biology, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218-2685, USA
| | - Eric L Lyons
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97403, USA
| | - Tory G Herman
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97403, USA.
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218-2685, USA.
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27
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Baugh LR, Hu PJ. Starvation Responses Throughout the Caenorhabditiselegans Life Cycle. Genetics 2020; 216:837-878. [PMID: 33268389 PMCID: PMC7768255 DOI: 10.1534/genetics.120.303565] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/17/2020] [Indexed: 02/07/2023] Open
Abstract
Caenorhabditis elegans survives on ephemeral food sources in the wild, and the species has a variety of adaptive responses to starvation. These features of its life history make the worm a powerful model for studying developmental, behavioral, and metabolic starvation responses. Starvation resistance is fundamental to life in the wild, and it is relevant to aging and common diseases such as cancer and diabetes. Worms respond to acute starvation at different times in the life cycle by arresting development and altering gene expression and metabolism. They also anticipate starvation during early larval development, engaging an alternative developmental program resulting in dauer diapause. By arresting development, these responses postpone growth and reproduction until feeding resumes. A common set of signaling pathways mediates systemic regulation of development in each context but with important distinctions. Several aspects of behavior, including feeding, foraging, taxis, egg laying, sleep, and associative learning, are also affected by starvation. A variety of conserved signaling, gene regulatory, and metabolic mechanisms support adaptation to starvation. Early life starvation can have persistent effects on adults and their descendants. With its short generation time, C. elegans is an ideal model for studying maternal provisioning, transgenerational epigenetic inheritance, and developmental origins of adult health and disease in humans. This review provides a comprehensive overview of starvation responses throughout the C. elegans life cycle.
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Affiliation(s)
- L Ryan Baugh
- Department of Biology, Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708 and
| | - Patrick J Hu
- Departments of Medicine and Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
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28
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Takeishi A, Yeon J, Harris N, Yang W, Sengupta P. Feeding state functionally reconfigures a sensory circuit to drive thermosensory behavioral plasticity. eLife 2020; 9:e61167. [PMID: 33074105 PMCID: PMC7644224 DOI: 10.7554/elife.61167] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/18/2020] [Indexed: 12/24/2022] Open
Abstract
Internal state alters sensory behaviors to optimize survival strategies. The neuronal mechanisms underlying hunger-dependent behavioral plasticity are not fully characterized. Here we show that feeding state alters C. elegans thermotaxis behavior by engaging a modulatory circuit whose activity gates the output of the core thermotaxis network. Feeding state does not alter the activity of the core thermotaxis circuit comprised of AFD thermosensory and AIY interneurons. Instead, prolonged food deprivation potentiates temperature responses in the AWC sensory neurons, which inhibit the postsynaptic AIA interneurons to override and disrupt AFD-driven thermotaxis behavior. Acute inhibition and activation of AWC and AIA, respectively, restores negative thermotaxis in starved animals. We find that state-dependent modulation of AWC-AIA temperature responses requires INS-1 insulin-like peptide signaling from the gut and DAF-16/FOXO function in AWC. Our results describe a mechanism by which functional reconfiguration of a sensory network via gut-brain signaling drives state-dependent behavioral flexibility.
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Affiliation(s)
- Asuka Takeishi
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Jihye Yeon
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Nathan Harris
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Wenxing Yang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard UniversityCambridgeUnited States
| | - Piali Sengupta
- Department of Biology, Brandeis UniversityWalthamUnited States
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29
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GABAergic motor neurons bias locomotor decision-making in C. elegans. Nat Commun 2020; 11:5076. [PMID: 33033264 PMCID: PMC7544903 DOI: 10.1038/s41467-020-18893-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 09/17/2020] [Indexed: 12/18/2022] Open
Abstract
Proper threat-reward decision-making is critical to animal survival. Emerging evidence indicates that the motor system may participate in decision-making but the neural circuit and molecular bases for these functions are little known. We found in C. elegans that GABAergic motor neurons (D-MNs) bias toward the reward behavior in threat-reward decision-making by retrogradely inhibiting a pair of premotor command interneurons, AVA, that control cholinergic motor neurons in the avoidance neural circuit. This function of D-MNs is mediated by a specific ionotropic GABA receptor (UNC-49) in AVA, and depends on electrical coupling between the two AVA interneurons. Our results suggest that AVA are hub neurons where sensory inputs from threat and reward sensory modalities and motor information from D-MNs are integrated. This study demonstrates at single-neuron resolution how motor neurons may help shape threat-reward choice behaviors through interacting with other neurons.
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30
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Fusogen-mediated neuron-neuron fusion disrupts neural circuit connectivity and alters animal behavior. Proc Natl Acad Sci U S A 2020; 117:23054-23065. [PMID: 32855296 PMCID: PMC7502713 DOI: 10.1073/pnas.1919063117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Ramón y Cajal’s neuron doctrine, which states that neurons are individual cells that do not share any membrane or cytoplasmic continuity between them, has underpinned our view of modern neuroscience. However, there is considerable evidence that fusogens, specialized proteins essential and sufficient for the fusion of cells in other tissues, are expressed in the nervous system of several species in response to viral infection, stress conditions, and neurological disease. By manipulating the expression of fusogens in the chemosensory neurons of Caenorhabditis elegans, our results provide conclusive evidence that deregulation of fusogen expression causes neuronal fusion and can have deleterious effects on neural circuitry and behavioral outputs, revealing a possible novel underlying cause of neurological disorders. The 100-y-old neuron doctrine from Ramón y Cajal states that neurons are individual cells, rejecting the process of cell−cell fusion in the normal development and function of the nervous system. However, fusogens—specialized molecules essential and sufficient for the fusion of cells—are expressed in the nervous system of different species under conditions of viral infection, stress, or disease. Despite these findings, whether the expression of fusogens in neurons leads to cell−cell fusion, and, if so, whether this affects neuronal fate, function, and animal behavior, has not been explored. Here, using Caenorhabditis elegans chemosensory neurons as a model system, we provide proof-of-principle that aberrant expression of fusogens in neurons results in neuron−neuron fusion and behavioral impairments. We demonstrate that fusion between chemoattractive neurons does not affect the response to odorants, whereas fusion between chemoattractive and chemorepulsive neurons compromises chemosensation. Moreover, we provide evidence that fused neurons are viable and retain their original specific neuronal fate markers. Finally, analysis of calcium transients reveals that fused neurons become electrically coupled, thereby compromising neural circuit connectivity. Thus, we propose that aberrant expression of fusogens in the nervous system disrupts neuronal individuality, which, in turn, leads to a change in neural circuit connectivity and disruption of normal behavior. Our results expose a previously uncharacterized basis of circuit malfunction, and a possible underlying cause of neurological diseases.
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31
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Harnessing the power of genetics: fast forward genetics in Caenorhabditis elegans. Mol Genet Genomics 2020; 296:1-20. [PMID: 32888055 DOI: 10.1007/s00438-020-01721-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 08/27/2020] [Indexed: 12/23/2022]
Abstract
Forward genetics is a powerful tool to unravel molecular mechanisms of diverse biological processes. The success of genetic screens primarily relies on the ease of genetic manipulation of an organism and the availability of a plethora of genetic tools. The roundworm Caenorhabditis elegans has been one of the favorite models for genetic studies due to its hermaphroditic lifestyle, ease of maintenance, and availability of various genetic manipulation tools. The strength of C. elegans genetics is highlighted by the leading role of this organism in the discovery of several conserved biological processes. In this review, the principles and strategies for forward genetics in C. elegans are discussed. Further, the recent advancements that have drastically accelerated the otherwise time-consuming process of mutation identification, making forward genetic screens a method of choice for understanding biological functions, are discussed. The emphasis of the review has been on providing practical and conceptual pointers for designing genetic screens that will identify mutations, specifically disrupting the biological processes of interest.
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32
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Jin EJ, Park S, Lyu X, Jin Y. Gap junctions: historical discoveries and new findings in the Caenorhabditiselegans nervous system. Biol Open 2020; 9:bio053983. [PMID: 32883654 PMCID: PMC7489761 DOI: 10.1242/bio.053983] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Gap junctions are evolutionarily conserved structures at close membrane contacts between two cells. In the nervous system, they mediate rapid, often bi-directional, transmission of signals through channels called innexins in invertebrates and connexins in vertebrates. Connectomic studies from Caenorhabditis elegans have uncovered a vast number of gap junctions present in the nervous system and non-neuronal tissues. The genome also has 25 innexin genes that are expressed in spatial and temporal dynamic pattern. Recent findings have begun to reveal novel roles of innexins in the regulation of multiple processes during formation and function of neural circuits both in normal conditions and under stress. Here, we highlight the diverse roles of gap junctions and innexins in the C. elegans nervous system. These findings contribute to fundamental understanding of gap junctions in all animals.
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Affiliation(s)
- Eugene Jennifer Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Seungmee Park
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xiaohui Lyu
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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33
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Fadda M, De Fruyt N, Borghgraef C, Watteyne J, Peymen K, Vandewyer E, Naranjo Galindo FJ, Kieswetter A, Mirabeau O, Chew YL, Beets I, Schoofs L. NPY/NPF-Related Neuropeptide FLP-34 Signals from Serotonergic Neurons to Modulate Aversive Olfactory Learning in Caenorhabditis elegans. J Neurosci 2020; 40:6018-6034. [PMID: 32576621 PMCID: PMC7392509 DOI: 10.1523/jneurosci.2674-19.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 04/26/2020] [Accepted: 06/12/2020] [Indexed: 02/03/2023] Open
Abstract
Aversive learning is fundamental for animals to increase chances of survival. In addition to classical neurotransmitters, neuropeptides have emerged to modulate such complex behaviors. Among them, neuropeptide Y (NPY) is well known to promote aversive memory acquisition in mammals. Here we identify an NPY/neuropeptide F (NPF)-related neuropeptide system in Caenorhabditis elegans and show that this FLP-34/NPR-11 system is required for learning negative associations, a process that is reminiscent of NPY signaling in mammals. The Caenorhabditis elegans NPY/NPF ortholog FLP-34 displays conserved structural hallmarks of bilaterian-wide NPY/NPF neuropeptides. We show that it is required for aversive olfactory learning after pairing diacetyl with the absence of food, but not for appetitive olfactory learning in response to butanone. To mediate diacetyl learning and thus integrate the aversive food context with the diacetyl odor, FLP-34 is released from serotonergic neurons and signals through its evolutionarily conserved NPY/NPF GPCR, NPR-11, in downstream AIA interneurons. NPR-11 activation in the AIA integration center results in avoidance of a previously attractive stimulus. This study opens perspectives for a deeper understanding of stress conditions in which aversive learning results in excessive avoidance.SIGNIFICANCE STATEMENT Aversive learning evolved early in evolution to promote avoidance of dangerous and stressful situations. In addition to classical neurotransmitters, neuropeptides are emerging as modulators of complex behaviors, including learning and memory. Here, we identified the evolutionary ortholog of neuropeptide Y/neuropeptide F in the nematode Caenorhabditis elegans, and we discovered that it is required for olfactory aversive learning. In addition, we elucidated the neural circuit underlying this avoidance behavior, and we discovered a novel coordinated action of Caenorhabditis elegans neuropeptide Y/neuropeptide F and serotonin that could aid in our understanding of the molecular mechanisms underlying stress disorders in which excessive avoidance results in maladaptive behaviors.
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Affiliation(s)
- Melissa Fadda
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | - Jan Watteyne
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | | | | | - Olivier Mirabeau
- Genetics and Biology of Cancers Unit, Institut Curie, Institut National de la Santé et de la Recherche Médicale U830, Paris Sciences et Lettres Research University, Paris, 75005, France
| | - Yee Lian Chew
- Illawarra Health & Medical Research Institute School of Chemistry & Molecular Bioscience, University of Wollongong, Wollongong, 2522 New South Wales, Australia
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
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Barrière A, Bertrand V. Neuronal specification in C. elegans: combining lineage inheritance with intercellular signaling. J Neurogenet 2020; 34:273-281. [PMID: 32603241 DOI: 10.1080/01677063.2020.1781850] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The nervous system is composed of a high diversity of neuronal types. How this diversity is generated during development is a key question in neurobiology. Addressing this question is one of the reasons that led Sydney Brenner to develop the nematode C. elegans as a model organism. While there was initially a debate on whether the neuronal specification follows a 'European' model (determined by ancestry) or an 'American' model (determined by intercellular communication), several decades of research have established that the truth lies somewhere in between. Neurons are specified by the combination of transcription factors inherited from the ancestor cells and signaling between neighboring cells (especially Wnt and Notch signaling). This converges to the activation in newly generated postmitotic neurons of a specific set of terminal selector transcription factors that initiate and maintain the differentiation of the neuron. In this review, we also discuss the evolution of these specification mechanisms in other nematodes and beyond.
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Affiliation(s)
- Antoine Barrière
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Vincent Bertrand
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
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35
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Dixit A, Sandhu A, Modi S, Shashikanth M, Koushika SP, Watts JL, Singh V. Neuronal control of lipid metabolism by STR-2 G protein-coupled receptor promotes longevity in Caenorhabditis elegans. Aging Cell 2020; 19:e13160. [PMID: 32432390 PMCID: PMC7294788 DOI: 10.1111/acel.13160] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 04/11/2020] [Accepted: 04/15/2020] [Indexed: 01/03/2023] Open
Abstract
The G protein-coupled receptor (GPCR) encoding family of genes constitutes more than 6% of genes in Caenorhabditis elegans genome. GPCRs control behavior, innate immunity, chemotaxis, and food search behavior. Here, we show that C. elegans longevity is regulated by a chemosensory GPCR STR-2, expressed in AWC and ASI amphid sensory neurons. STR-2 function is required at temperatures of 20°C and higher on standard Escherichia coli OP50 diet. Under these conditions, this neuronal receptor also controls health span parameters and lipid droplet (LD) homeostasis in the intestine. We show that STR-2 regulates expression of delta-9 desaturases, fat-5, fat-6 and fat-7, and of diacylglycerol acyltransferase dgat-2. Rescue of the STR-2 function in either AWC and ASI, or ASI sensory neurons alone, restores expression of fat-5, dgat-2 and restores LD stores and longevity. Rescue of stored fat levels of GPCR mutant animals to wild-type levels, with low concentration of glucose, rescues its lifespan phenotype. In all, we show that neuronal STR-2 GPCR facilitates control of neutral lipid levels and longevity in C. elegans.
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Affiliation(s)
- Anubhuti Dixit
- Department of Molecular Reproduction, Development and GeneticsIndian Institute of ScienceBangaloreIndia
- Present address:
Amity Institute of Neuropsychology and NeurosciencesAmity UniversityNoidaIndia
| | - Anjali Sandhu
- Department of Molecular Reproduction, Development and GeneticsIndian Institute of ScienceBangaloreIndia
| | - Souvik Modi
- Department of Biological SciencesTata Institute of Fundamental ResearchMumbaiIndia
| | - Meghana Shashikanth
- Department of Molecular Reproduction, Development and GeneticsIndian Institute of ScienceBangaloreIndia
| | - Sandhya P. Koushika
- Department of Biological SciencesTata Institute of Fundamental ResearchMumbaiIndia
| | - Jennifer L. Watts
- School of Molecular BiosciencesWashington State UniversityPullmanWAUSA
| | - Varsha Singh
- Department of Molecular Reproduction, Development and GeneticsIndian Institute of ScienceBangaloreIndia
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36
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Foster KJ, Cheesman HK, Liu P, Peterson ND, Anderson SM, Pukkila-Worley R. Innate Immunity in the C. elegans Intestine Is Programmed by a Neuronal Regulator of AWC Olfactory Neuron Development. Cell Rep 2020; 31:107478. [PMID: 32268082 PMCID: PMC7215899 DOI: 10.1016/j.celrep.2020.03.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/15/2020] [Accepted: 03/13/2020] [Indexed: 12/22/2022] Open
Abstract
Olfactory neurons allow animals to discriminate nutritious food sources from potential pathogens. From a forward genetic screen, we uncovered a surprising requirement for the olfactory neuron gene olrn-1 in the regulation of intestinal epithelial immunity in Caenorhabditis elegans. During nematode development, olrn-1 is required to program the expression of odorant receptors in the AWC olfactory neuron pair. Here, we show that olrn-1 also functions in AWC neurons in the cell non-autonomous suppression of the canonical p38 MAPK PMK-1 immune pathway in the intestine. Low activity of OLRN-1, which activates the p38 MAPK signaling cassette in AWC neurons during larval development, also de-represses the p38 MAPK PMK-1 pathway in the intestine to promote immune effector transcription, increased clearance of an intestinal pathogen, and resistance to bacterial infection. These data reveal an unexpected connection between olfactory receptor development and innate immunity and show that anti-pathogen defenses in the intestine are developmentally programmed.
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Affiliation(s)
- Kyle J Foster
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Hilary K Cheesman
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Pengpeng Liu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Nicholas D Peterson
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Sarah M Anderson
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Read Pukkila-Worley
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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Mutlu AS, Gao SM, Zhang H, Wang MC. Olfactory specificity regulates lipid metabolism through neuroendocrine signaling in Caenorhabditis elegans. Nat Commun 2020; 11:1450. [PMID: 32193370 PMCID: PMC7081233 DOI: 10.1038/s41467-020-15296-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 02/20/2020] [Indexed: 01/01/2023] Open
Abstract
Olfactory and metabolic dysfunctions are intertwined phenomena associated with obesity and neurodegenerative diseases; yet how mechanistically olfaction regulates metabolic homeostasis remains unclear. Specificity of olfactory perception integrates diverse environmental odors and olfactory neurons expressing different receptors. Here, we report that specific but not all olfactory neurons actively regulate fat metabolism without affecting eating behaviors in Caenorhabditis elegans, and identified specific odors that reduce fat mobilization via inhibiting these neurons. Optogenetic activation or inhibition of the responsible olfactory neural circuit promotes the loss or gain of fat storage, respectively. Furthermore, we discovered that FLP-1 neuropeptide released from this olfactory neural circuit signals through peripheral NPR-4/neuropeptide receptor, SGK-1/serum- and glucocorticoid-inducible kinase, and specific isoforms of DAF-16/FOXO transcription factor to regulate fat storage. Our work reveals molecular mechanisms underlying olfactory regulation of fat metabolism, and suggests the association between olfactory perception specificity of each individual and his/her susceptibility to the development of obesity.
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Affiliation(s)
- Ayse Sena Mutlu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA.
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Shihong Max Gao
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Haining Zhang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA.
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, 77030, USA.
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Abstract
The capacity to respond to adverse conditions is key for animal survival. Research in the nematode Caenorhabditis elegans demonstrates that retrieval of aversive memories, stored within sensory neurons, is sufficient to induce a protective systemic stress response that improves fitness.
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Affiliation(s)
- Menachem Katz
- The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
| | - Shai Shaham
- The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
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A universal transportin protein drives stochastic choice of olfactory neurons via specific nuclear import of a sox-2-activating factor. Proc Natl Acad Sci U S A 2019; 116:25137-25146. [PMID: 31767767 DOI: 10.1073/pnas.1908168116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Stochastic neuronal cell fate choice involving notch-independent mechanisms is a poorly understood biological process. The Caenorhabditis elegans AWC olfactory neuron pair asymmetrically differentiates into the default AWCOFF and induced AWCON subtypes in a stochastic manner. Stochastic choice of the AWCON subtype is established using gap junctions and SLO BK potassium channels to repress a calcium-activated protein kinase pathway. However, it is unknown how the potassium channel-repressed calcium signaling is translated into the induction of the AWCON subtype. Here, we identify a detailed working mechanism of how the homeodomain-like transcription factor NSY-7, previously described as a repressor in the maintenance of AWC asymmetry, couples SLO BK potassium channels to transactivation of sox-2 expression for the induction of the AWCON subtype through the identification of a unique imb-2 (transportin 1) allele. imb-2 loss-of-function mutants are not viable; however, we identify a viable imb-2 allele from an unbiased forward genetic screen that reveals a specific role of imb-2 in AWC olfactory neuron asymmetry. IMB-2 specifically drives nuclear import of NSY-7 within AWC neurons to transactivate the expression of the high mobility group (HMG)-box transcription factor SOX-2 for the specification of the AWCON subtype. This study provides mechanistic insight into how NSY-7 couples SLO BK potassium channels to transactivation of sox-2 expression for the induction of the AWCON subtype. Our findings also provide structure-function insight into a conserved amino acid residue of transportins in brain development and suggest its dysfunction may lead to human neurological disorders.
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40
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Horowitz LB, Brandt JP, Ringstad N. Repression of an activity-dependent autocrine insulin signal is required for sensory neuron development in C. elegans. Development 2019; 146:dev.182873. [PMID: 31628111 DOI: 10.1242/dev.182873] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/14/2019] [Indexed: 11/20/2022]
Abstract
Nervous system development is instructed by genetic programs and refined by distinct mechanisms that couple neural activity to gene expression. How these processes are integrated remains poorly understood. Here, we report that the regulated release of insulin-like peptides (ILPs) during development of the Caenorhabditis elegans nervous system accomplishes such an integration. We find that the p38 MAP kinase PMK-3, which is required for the differentiation of chemosensory BAG neurons, limits an ILP signal that represses expression of a BAG neuron fate. ILPs are released from BAGs themselves in an activity-dependent manner during development, indicating that ILPs constitute an autocrine signal that regulates the differentiation of BAG neurons. Expression of a specialized neuronal fate is, therefore, coordinately regulated by a genetic program that sets levels of ILP expression during development, and by neural activity, which regulates ILP release. Autocrine signals of this kind might have general and conserved functions as integrators of deterministic genetic programs with activity-dependent mechanisms during neurodevelopment.
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Affiliation(s)
- Lauren Bayer Horowitz
- Skirball Institute of Biomolecular Medicine, Helen L. and Martin S. Kimmel Center for Biology and Medicine, Department of Cell Biology, Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
| | - Julia P Brandt
- Skirball Institute of Biomolecular Medicine, Helen L. and Martin S. Kimmel Center for Biology and Medicine, Department of Cell Biology, Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
| | - Niels Ringstad
- Skirball Institute of Biomolecular Medicine, Helen L. and Martin S. Kimmel Center for Biology and Medicine, Department of Cell Biology, Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
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41
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Packer JS, Zhu Q, Huynh C, Sivaramakrishnan P, Preston E, Dueck H, Stefanik D, Tan K, Trapnell C, Kim J, Waterston RH, Murray JI. A lineage-resolved molecular atlas of C. elegans embryogenesis at single-cell resolution. Science 2019; 365:eaax1971. [PMID: 31488706 PMCID: PMC7428862 DOI: 10.1126/science.aax1971] [Citation(s) in RCA: 244] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 08/21/2019] [Indexed: 12/18/2022]
Abstract
Caenorhabditis elegans is an animal with few cells but a wide diversity of cell types. In this study, we characterize the molecular basis for their specification by profiling the transcriptomes of 86,024 single embryonic cells. We identify 502 terminal and preterminal cell types, mapping most single-cell transcriptomes to their exact position in C. elegans' invariant lineage. Using these annotations, we find that (i) the correlation between a cell's lineage and its transcriptome increases from middle to late gastrulation, then falls substantially as cells in the nervous system and pharynx adopt their terminal fates; (ii) multilineage priming contributes to the differentiation of sister cells at dozens of lineage branches; and (iii) most distinct lineages that produce the same anatomical cell type converge to a homogenous transcriptomic state.
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Affiliation(s)
- Jonathan S Packer
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Qin Zhu
- Genomics and Computational Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
| | - Chau Huynh
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Priya Sivaramakrishnan
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elicia Preston
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hannah Dueck
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Derek Stefanik
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Kai Tan
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Junhyong Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Robert H Waterston
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
| | - John I Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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42
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How Caenorhabditis elegans Senses Mechanical Stress, Temperature, and Other Physical Stimuli. Genetics 2019; 212:25-51. [PMID: 31053616 PMCID: PMC6499529 DOI: 10.1534/genetics.118.300241] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/04/2019] [Indexed: 12/30/2022] Open
Abstract
Caenorhabditis elegans lives in a complex habitat in which they routinely experience large fluctuations in temperature, and encounter physical obstacles that vary in size and composition. Their habitat is shared by other nematodes, by beneficial and harmful bacteria, and nematode-trapping fungi. Not surprisingly, these nematodes can detect and discriminate among diverse environmental cues, and exhibit sensory-evoked behaviors that are readily quantifiable in the laboratory at high resolution. Their ability to perform these behaviors depends on <100 sensory neurons, and this compact sensory nervous system together with powerful molecular genetic tools has allowed individual neuron types to be linked to specific sensory responses. Here, we describe the sensory neurons and molecules that enable C. elegans to sense and respond to physical stimuli. We focus primarily on the pathways that allow sensation of mechanical and thermal stimuli, and briefly consider this animal’s ability to sense magnetic and electrical fields, light, and relative humidity. As the study of sensory transduction is critically dependent upon the techniques for stimulus delivery, we also include a section on appropriate laboratory methods for such studies. This chapter summarizes current knowledge about the sensitivity and response dynamics of individual classes of C. elegans mechano- and thermosensory neurons from in vivo calcium imaging and whole-cell patch-clamp electrophysiology studies. We also describe the roles of conserved molecules and signaling pathways in mediating the remarkably sensitive responses of these nematodes to mechanical and thermal cues. These studies have shown that the protein partners that form mechanotransduction channels are drawn from multiple superfamilies of ion channel proteins, and that signal transduction pathways responsible for temperature sensing in C. elegans share many features with those responsible for phototransduction in vertebrates.
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43
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PIM-Related Kinases Selectively Regulate Olfactory Sensations in Caenorhabditis elegans. eNeuro 2019; 6:ENEURO.0003-19.2019. [PMID: 31387876 PMCID: PMC6709224 DOI: 10.1523/eneuro.0003-19.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 07/12/2019] [Accepted: 07/18/2019] [Indexed: 11/21/2022] Open
Abstract
The mammalian PIM family of serine/threonine kinases regulate several cellular functions, such as cell survival and motility. Because PIM expression is observed in sensory organs, such as olfactory epithelium, we now wanted to explore the physiological roles of PIM kinases there. As our model organism, we used the Caenorhabditis elegans nematodes, which express two PIM-related kinases, PRK-1 and PRK-2. We demonstrated PRKs to be true PIM orthologs with similar substrate specificity as well as sensitivity to PIM-inhibitory compounds. When we analyzed the effects of pan-PIM inhibitors on C. elegans sensory functions, we observed that PRK activity is selectively required to support olfactory sensations to volatile repellents and attractants sensed by AWB and AWCON neurons, respectively, but is dispensable for gustatory sensations. Analyses of prk-deficient mutant strains confirmed these findings and suggested that PRK-1, but not PRK-2 is responsible for the observed effects on olfaction. This regulatory role of PRK-1 is further supported by its observed expression in the head and tail neurons, including AWB and AWC neurons. Based on the evolutionary conservation of PIM-related kinases, our data may have implications in regulation of also mammalian olfaction.
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44
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Differential Regulation of Innate and Learned Behavior by Creb1/Crh-1 in Caenorhabditis elegans. J Neurosci 2019; 39:7934-7946. [PMID: 31413073 PMCID: PMC6774408 DOI: 10.1523/jneurosci.0006-19.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 06/17/2019] [Accepted: 07/30/2019] [Indexed: 12/18/2022] Open
Abstract
Memory formation is crucial for the survival of animals. Here, we study the effect of different crh-1 [Caenorhabditis elegans homolog of mammalian cAMP response element binding protein 1 (CREB1)] isoforms on the ability of C. elegans to form long-term memory (LTM). Null mutants in creb1/crh-1 are defective in LTM formation across phyla. We show that a specific isoform of CREB1/CRH-1, CRH-1e, is primarily responsible for memory related functions of the transcription factor in C. elegans. Silencing of CRH-1e-expressing neurons during training for LTM formation abolishes the LTM of the animal. Further, CRH-1e expression in RIM neurons is sufficient to rescue LTM defects of creb1/crh-1-null mutants. We go on to show that apart from being LTM defective, creb1/crh-1-null animals show defects in innate chemotaxis behavior. We further characterize the amino acids K247 and K266 as responsible for the LTM related functions of CREB1/CRH-1 while being dispensable for its innate chemotaxis behavior. These findings provide insight into the spatial and temporal workings of a crucial transcription factor that can be further exploited to find CREB1 targets involved in the process of memory formation. SIGNIFICANCE STATEMENT This study elucidates the role of a specific isoform of CREB1/CRH-1, CRH-1e, in Caenorhabditis elegans memory formation and chemosensation. Removal of this single isoform of creb1/crh-1 shows defects in long-term memory formation in the animal and expression of CREB1/CRH-1e in a single pair of neurons is sufficient to rescue the memory defects seen in the mutant animals. We further show that two specific amino acids of CRH-1 are required for the process of memory formation in the animal.
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45
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Foley SJ, Wu Z, Politz SM. A C. elegans MAP kinase pathway is required for wild-type display of an L1-specific surface antigen ( srf-6 is nsy-1 III). MICROPUBLICATION BIOLOGY 2019; 2019:10.17912/micropub.biology.000129. [PMID: 32550420 PMCID: PMC7252279 DOI: 10.17912/micropub.biology.000129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Stephen J. Foley
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA
| | - Zheyang Wu
- Department of Mathematical Sciences, Worcester Polytechnic Institute, Worcester, MA
| | - Samuel M. Politz
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA,
Correspondence to: Samuel M. Politz ()
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46
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Honzel BE, Foley SJ, Politz SM. C. elegans srf-6 and nsy-1 mutations result in a similar 2AWC ON phenotype and do not complement ( srf-6 is nsy-1 II). MICROPUBLICATION BIOLOGY 2019; 2019:10.17912/micropub.biology.000128. [PMID: 32550425 PMCID: PMC7252294 DOI: 10.17912/micropub.biology.000128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Brooke E. Honzel
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA
| | - Stephen J. Foley
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA
| | - Samuel M. Politz
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA,
Correspondence to: Samuel M. Politz ()
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47
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Politz SM. Role of the p38 MAP kinase pathway in C. elegans surface antigen switching. MICROPUBLICATION BIOLOGY 2019; 2019:10.17912/micropub.biology.000130. [PMID: 32550455 PMCID: PMC7252348 DOI: 10.17912/micropub.biology.000130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Samuel M. Politz
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA,
Correspondence to: Samuel M. Politz ()
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48
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Worthy SE, Rojas GL, Taylor CJ, Glater EE. Identification of Odor Blend Used by Caenorhabditis elegans for Pathogen Recognition. Chem Senses 2019; 43:169-180. [PMID: 29373666 PMCID: PMC6018680 DOI: 10.1093/chemse/bjy001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Animals have evolved specialized pathways to detect appropriate food sources and avoid harmful ones. Caenorhabditis elegans can distinguish among the odors of various species of bacteria, its major food source, but little is known about what specific chemical cue or combination of chemical cues C. elegans uses to detect and recognize different microbes. Here, we examine the strong innate attraction of C. elegans for the odor of the pathogenic bacterium, Serratia marcescens. This initial attraction likely facilitates ingestion and infection of the C. elegans host. Using solid-phase microextraction and gas chromatography coupled with mass spectrometry, we identify 5 volatile odors released by S. marcescens and identify those that are attractive to C. elegans. We use genetic methods to show that the amphid chemosensory neuron, AWCON, senses both S. marcescens-released 2-butanone and acetone and drives attraction to S. marcescens. In C. elegans, pairing a single odorant with food deprivation results in a reduced attractive response for that specific odor. We find that pairing the natural odor of S. marcescens with food deprivation results in a reduced attraction for the natural odor of S. marcescens and a similar reduced attraction for the synthetic blend of acetone and 2-butanone. This result indicates that only 2 odorants represent the more complex odor bouquet of S. marcescens. Although bacterial-released volatiles have long been known to be attractive to C. elegans, this study defines for the first time specific volatile cues that represent a particular bacterium to C. elegans.
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Affiliation(s)
| | - German L Rojas
- Department of Neuroscience, Pomona College, Claremont, CA, USA
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49
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Multiple Pathways Act Together To Establish Asymmetry of the Ventral Nerve Cord in Caenorhabditis elegans. Genetics 2019; 211:1331-1343. [PMID: 30792268 DOI: 10.1534/genetics.119.301999] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 02/15/2019] [Indexed: 01/30/2023] Open
Abstract
The central nervous system of most animals is bilaterally symmetrical. Closer observation often reveals some functional or anatomical left-right asymmetries. In the nematode Caenorhabditis elegans, the most obvious asymmetry in the nervous system is found in the ventral nerve cord (VNC), where most axons are in the right axon tract. The asymmetry is established when axons entering the VNC from the brain switch from the left to the right side at the anterior end of the VNC. In genetic screens we identified several mutations compromising VNC asymmetry. This includes alleles of col-99 (encoding a transmembrane collagen), unc-52/perlecan and unc-34 (encoding the actin modulator Enabled/Vasodilator-stimulated phosphoproteins). In addition, we evaluated mutants in known axon guidance pathways for asymmetry defects and used genetic interaction studies to place the genes into genetic pathways. In total we identified four different pathways contributing to the establishment of VNC asymmetry, represented by UNC-6/netrin, SAX-3/Robo, COL-99, and EPI-1/laminin. The combined inactivation of these pathways in triple and quadruple mutants leads to highly penetrant VNC asymmetry defects, suggesting these pathways are important contributors to the establishment of VNC asymmetry in C. elegans.
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50
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Li N, van der Kooy D. Mutations in the guanylate cyclase gcy-28 neuronally dissociate naïve attraction and memory retrieval. Eur J Neurosci 2018; 48:3367-3378. [PMID: 30362188 DOI: 10.1111/ejn.14221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 09/26/2018] [Accepted: 10/10/2018] [Indexed: 11/28/2022]
Abstract
The molecules and mechanisms that are involved in the acquisition, storage, and retrieval of memories in many organisms are unclear. To investigate these processes, we use the nematode worm Caenorhabditis elegans, which is attracted naïvely to the odorant benzaldehyde but learns to avoid it after paired exposure with starvation. Mutations in the receptor-like guanylate cyclase GCY-28 have previously been thought to result in a behavioral switch in the primary chemosensory neuron AWCON , from an attractive state to an aversive (already-learned) state. Here, we offer a different interpretation and show that GCY-28 functions in distinct neurons to modulate two independent processes: naïve attraction to AWCON -sensed odors in the AWCON neuron, and associative learning of benzaldehyde and starvation in the AIA interneurons. Consequently, mutants that lack gcy-28 do not approach AWCON -sensed odors and cannot associate benzaldehyde with starvation. We further show that this learning deficit lies in memory retrieval, not in its acquisition or storage, and that GCY-28 is required in AIA for sensory integration only when both AWC neurons (ON and OFF) are activated by chemical stimuli. Our results reveal a novel role of GCY-28 in the retrieval of associative memories and may have wide implications for the neural machineries of learning and memory in general.
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Affiliation(s)
- Naijin Li
- The Donnelly Centre for Cellular and Biomolecular Research, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Derek van der Kooy
- The Donnelly Centre for Cellular and Biomolecular Research, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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