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Zhang MG, Seyedolmohadesin M, Mercado SH, Tauffenberger A, Park H, Finnen N, Schroeder FC, Venkatachalam V, Sternberg PW. Sensory integration of food and population density during the diapause exit decision involves insulin-like signaling in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2024; 121:e2405391121. [PMID: 39316052 DOI: 10.1073/pnas.2405391121] [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: 03/19/2024] [Accepted: 08/20/2024] [Indexed: 09/25/2024] Open
Abstract
Decisions made over long time scales, such as life cycle decisions, require coordinated interplay between sensory perception and sustained gene expression. The Caenorhabditis elegans dauer (or diapause) exit developmental decision requires sensory integration of population density and food availability to induce an all-or-nothing organismal-wide response, but the mechanism by which this occurs remains unknown. Here, we demonstrate how the Amphid Single Cilium J (ASJ) chemosensory neurons, known to be critical for dauer exit, perform sensory integration at both the levels of gene expression and calcium activity. In response to favorable conditions, dauers rapidly produce and secrete the dauer exit-promoting insulin-like peptide INS-6. Expression of ins-6 in the ASJ neurons integrates population density and food level and can reflect decision commitment since dauers committed to exiting have higher ins-6 expression levels than those of noncommitted dauers. Calcium imaging in dauers reveals that the ASJ neurons are activated by food, and this activity is suppressed by pheromone, indicating that sensory integration also occurs at the level of calcium transients. We find that ins-6 expression in the ASJ neurons depends on neuronal activity in the ASJs, cGMP signaling, and the pheromone components ascr#8 and ascr#2. We propose a model in which decision commitment to exit the dauer state involves an autoregulatory feedback loop in the ASJ neurons that promotes high INS-6 production and secretion. These results collectively demonstrate how insulin-like peptide signaling helps animals compute long-term decisions by bridging sensory perception to decision execution.
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Affiliation(s)
- Mark G Zhang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | | | - Soraya Hawk Mercado
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Arnaud Tauffenberger
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - Heenam Park
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Nerissa Finnen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Frank C Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | | | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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2
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Zhang Y, Iino Y, Schafer WR. Behavioral plasticity. Genetics 2024; 228:iyae105. [PMID: 39158469 DOI: 10.1093/genetics/iyae105] [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: 02/01/2024] [Accepted: 06/10/2024] [Indexed: 08/20/2024] Open
Abstract
Behavioral plasticity allows animals to modulate their behavior based on experience and environmental conditions. Caenorhabditis elegans exhibits experience-dependent changes in its behavioral responses to various modalities of sensory cues, including odorants, salts, temperature, and mechanical stimulations. Most of these forms of behavioral plasticity, such as adaptation, habituation, associative learning, and imprinting, are shared with other animals. The C. elegans nervous system is considerably tractable for experimental studies-its function can be characterized and manipulated with molecular genetic methods, its activity can be visualized and analyzed with imaging approaches, and the connectivity of its relatively small number of neurons are well described. Therefore, C. elegans provides an opportunity to study molecular, neuronal, and circuit mechanisms underlying behavioral plasticity that are either conserved in other animals or unique to this species. These findings reveal insights into how the nervous system interacts with the environmental cues to generate behavioral changes with adaptive values.
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Affiliation(s)
- Yun Zhang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Yuichi Iino
- Department of Biological Sciences, University of Tokyo, Tokyo 113-0032, Japan
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire CB2 0QH, UK
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
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3
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Lei M, Tan Y, Tu H, Tan W. Neuronal basis and diverse mechanisms of pathogen avoidance in Caenorhabditis elegans. Front Immunol 2024; 15:1353747. [PMID: 38751431 PMCID: PMC11094273 DOI: 10.3389/fimmu.2024.1353747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 04/22/2024] [Indexed: 05/18/2024] Open
Abstract
Pathogen avoidance behaviour has been observed across animal taxa as a vital host-microbe interaction mechanism. The nematode Caenorhabditis elegans has evolved multiple diverse mechanisms for pathogen avoidance under natural selection pressure. We summarise the current knowledge of the stimuli that trigger pathogen avoidance, including alterations in aerotaxis, intestinal bloating, and metabolites. We then survey the neural circuits involved in pathogen avoidance, transgenerational epigenetic inheritance of pathogen avoidance, signalling crosstalk between pathogen avoidance and innate immunity, and C. elegans avoidance of non-Pseudomonas bacteria. In this review, we highlight the latest advances in understanding host-microbe interactions and the gut-brain axis.
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Affiliation(s)
- Ming Lei
- Academy of Medical Engineering and Translational Medicine (AMT), Tianjin University, Tianjin, China
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
- The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang, China
| | - Yanheng Tan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
| | - Haijun Tu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
| | - Weihong Tan
- Academy of Medical Engineering and Translational Medicine (AMT), Tianjin University, Tianjin, China
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
- The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang, China
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4
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Zhang MG, Seyedolmohadesin M, Hawk S, Park H, Finnen N, Schroeder F, Venkatachalam V, Sternberg PW. Sensory integration of food availability and population density during the diapause exit decision involves insulin-like signaling in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.586022. [PMID: 38586049 PMCID: PMC10996498 DOI: 10.1101/2024.03.20.586022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Decisions made over long time scales, such as life cycle decisions, require coordinated interplay between sensory perception and sustained gene expression. The Caenorhabditis elegans dauer (or diapause) exit developmental decision requires sensory integration of population density and food availability to induce an all-or-nothing organismal-wide response, but the mechanism by which this occurs remains unknown. Here, we demonstrate how the ASJ chemosensory neurons, known to be critical for dauer exit, perform sensory integration at both the levels of gene expression and calcium activity. In response to favorable conditions, dauers rapidly produce and secrete the dauer exit-promoting insulin-like peptide INS-6. Expression of ins-6 in the ASJ neurons integrate population density and food level and can reflect decision commitment since dauers committed to exiting have higher ins-6 expression levels than those of non-committed dauers. Calcium imaging in dauers reveals that the ASJ neurons are activated by food, and this activity is suppressed by pheromone, indicating that sensory integration also occurs at the level of calcium transients. We find that ins-6 expression in the ASJ neurons depends on neuronal activity in the ASJs, cGMP signaling, a CaM-kinase pathway, and the pheromone components ascr#8 and ascr#2. We propose a model in which decision commitment to exit the dauer state involves an autoregulatory feedback loop in the ASJ neurons that promotes high INS-6 production and secretion. These results collectively demonstrate how insulin-like peptide signaling helps animals compute long-term decisions by bridging sensory perception to decision execution.
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Affiliation(s)
- Mark G Zhang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | | | - Soraya Hawk
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Heenam Park
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nerissa Finnen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Frank Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | | | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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5
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Boor SA, Meisel JD, Kim DH. Neuroendocrine gene expression coupling of interoceptive bacterial food cues to foraging behavior of C. elegans. eLife 2024; 12:RP91120. [PMID: 38231572 PMCID: PMC10945577 DOI: 10.7554/elife.91120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024] Open
Abstract
Animal internal state is modulated by nutrient intake, resulting in behavioral responses to changing food conditions. The neural mechanisms by which internal states are generated and maintained are not well understood. Here, we show that in the nematode Caenorhabditis elegans, distinct cues from bacterial food - interoceptive signals from the ingestion of bacteria and gustatory molecules sensed from nearby bacteria - act antagonistically on the expression of the neuroendocrine TGF-beta ligand DAF-7 from the ASJ pair of sensory neurons to modulate foraging behavior. A positive-feedback loop dependent on the expression of daf-7 from the ASJ neurons acts to promote transitions between roaming and dwelling foraging states and influence the persistence of roaming states. SCD-2, the C. elegans ortholog of mammalian anaplastic lymphoma kinase (ALK), which has been implicated in the central control of metabolism of mammals, functions in the AIA interneurons to regulate foraging behavior and cell-non-autonomously control the expression of DAF-7 from the ASJ neurons. Our data establish how a dynamic neuroendocrine daf-7 expression feedback loop regulated by SCD-2 functions to couple sensing and ingestion of bacterial food to foraging behavior. We further suggest that this neuroendocrine feedback loop underlies previously characterized exploratory behaviors in C. elegans. Our data suggest that the expression of daf-7 from the ASJ neurons contributes to and is correlated with an internal state of 'unmet need' that regulates exploratory foraging behavior in response to bacterial cues in diverse physiological contexts.
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Affiliation(s)
- Sonia A Boor
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical SchoolBostonUnited States
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Joshua D Meisel
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
- Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
| | - Dennis H Kim
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical SchoolBostonUnited States
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Lee H, Boor SA, Hilbert ZA, Meisel JD, Park J, Wang Y, McKeown R, Fischer SEJ, Andersen EC, Kim DH. Genetic Variants That Modify the Neuroendocrine Regulation of Foraging Behavior in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.09.556976. [PMID: 37745484 PMCID: PMC10515746 DOI: 10.1101/2023.09.09.556976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The molecular mechanisms underlying diversity in animal behavior are not well understood. A major experimental challenge is determining the contribution of genetic variants that affect neuronal gene expression to differences in behavioral traits. The neuroendocrine TGF-beta ligand, DAF-7, regulates diverse behavioral responses of Caenorhabditis elegans to bacterial food and pathogens. The dynamic neuron-specific expression of daf-7 is modulated by environmental and endogenous bacteria-derived cues. Here, we investigated natural variation in the expression of daf-7 from the ASJ pair of chemosensory neurons and identified common variants in gap-2, encoding a GTPase-Activating Protein homologous to mammalian SynGAP proteins, which modify daf-7 expression cell-non-autonomously and promote exploratory foraging behavior in a DAF-7-dependent manner. Our data connect natural variation in neuron-specific gene expression to differences in behavior and suggest that genetic variation in neuroendocrine signaling pathways mediating host-microbe interactions may give rise to diversity in animal behavior.
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Affiliation(s)
- Harksun Lee
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
| | - Sonia A. Boor
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, 02139, USA
| | - Zoë A. Hilbert
- Department of Biology, Massachusetts Institute of Technology; Cambridge, 02139, USA
| | - Joshua D. Meisel
- Department of Biology, Massachusetts Institute of Technology; Cambridge, 02139, USA
| | - Jaeseok Park
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
| | - Ye Wang
- Department of Molecular Biosciences, Northwestern University; Evanston, 60208, USA
| | - Ryan McKeown
- Department of Molecular Biosciences, Northwestern University; Evanston, 60208, USA
| | - Sylvia E. J. Fischer
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University; Evanston, 60208, USA
| | - Dennis H. Kim
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
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7
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Hernandez-Lima MA, Champion M, Mattiola Z, Truttmann MC. The AMPylase FIC-1 modulates TGF-β signaling in Caenorhabditis elegans. Front Mol Neurosci 2022; 15:912734. [PMID: 36504677 PMCID: PMC9730714 DOI: 10.3389/fnmol.2022.912734] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 11/03/2022] [Indexed: 11/25/2022] Open
Abstract
Post-translational protein modifications are essential for the spatio-temporal regulation of protein function. In this study, we examine how the activity of the Caenorhabditis elegans AMPylase FIC-1 modulates physiological processes in vivo. We find that over-expression (OE) of the constitutive AMPylase FIC-1(E274G) impairs C. elegans development, fertility, and stress resilience. We also show that FIC-1(E274G) OE inhibits pathogen avoidance behavior by selectively suppressing production of the Transforming Growth Factor-β (TGF-β) ligands DAF-7 and DBL-1 in ASI sensory neurons. Finally, we demonstrate that FIC-1 contributes to the regulation of adult body growth, cholinergic neuron function, and larval entry into dauer stage; all processes controlled by TGF-β signaling. Together, our results suggest a role for FIC-1 in regulating TGF-β signaling in C. elegans.
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Affiliation(s)
- Mirella A. Hernandez-Lima
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Margaret Champion
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Zachary Mattiola
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Matthias C. Truttmann
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States,Geriatrics Center, University of Michigan, Ann Arbor, MI, United States,*Correspondence: Matthias C. Truttmann,
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8
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Microbiomes: How a gut bacterium promotes healthier living in a nematode. Curr Biol 2022; 32:R428-R430. [DOI: 10.1016/j.cub.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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9
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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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10
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Abstract
Microbes are ubiquitous in the natural environment of Caenorhabditis elegans. Bacteria serve as a food source for C. elegans but may also cause infection in the nematode host. The sensory nervous system of C. elegans detects diverse microbial molecules, ranging from metabolites produced by broad classes of bacteria to molecules synthesized by specific strains of bacteria. Innate recognition through chemosensation of bacterial metabolites or mechanosensation of bacteria can induce immediate behavioral responses. The ingestion of nutritive or pathogenic bacteria can modulate internal states that underlie long-lasting behavioral changes. Ingestion of nutritive bacteria leads to learned attraction and exploitation of the bacterial food source. Infection, which is accompanied by activation of innate immunity, stress responses, and host damage, leads to the development of aversive behavior. The integration of a multitude of microbial sensory cues in the environment is shaped by experience and context. Genetic, chemical, and neuronal studies of C. elegans behavior in the presence of bacteria have defined neural circuits and neuromodulatory systems that shape innate and learned behavioral responses to microbial cues. These studies have revealed the profound influence that host-microbe interactions have in governing the behavior of this simple animal host.
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Affiliation(s)
- Dennis H Kim
- Division of Infectious Diseases, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Steven W Flavell
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
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