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Ma F, Zheng C. Single-cell phylotranscriptomics of developmental and cell type evolution. Trends Genet 2024; 40:495-510. [PMID: 38490933 DOI: 10.1016/j.tig.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/16/2024] [Accepted: 02/16/2024] [Indexed: 03/17/2024]
Abstract
Single-cell phylotranscriptomics is an emerging tool to reveal the molecular and cellular mechanisms of evolution. We summarize its utility in studying the hourglass pattern of ontogenetic evolution and for understanding the evolutionary history of cell types. The developmental hourglass model suggests that the mid-embryonic stage is the most conserved period of development across species, which is supported by morphological and molecular studies. Single-cell phylotranscriptomic analysis has revealed previously underappreciated heterogeneity in transcriptome ages among lineages and cell types throughout development, and has identified the lineages and tissues that drive the whole-organism hourglass pattern. Single-cell transcriptome age analyses also provide important insights into the origin of germ layers, the different selective forces on tissues during adaptation, and the evolutionary relationships between cell types.
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Affiliation(s)
- Fuqiang Ma
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Chaogu Zheng
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China.
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2
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Brissette B, Ficaro L, Li C, Jones DR, Ramanathan S, Ringstad N. Chemosensory detection of polyamine metabolites guides C. elegans to nutritive microbes. SCIENCE ADVANCES 2024; 10:eadj4387. [PMID: 38517971 PMCID: PMC10959419 DOI: 10.1126/sciadv.adj4387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 02/16/2024] [Indexed: 03/24/2024]
Abstract
Much is known about molecular mechanisms by which animals detect pathogenic microbes, but how animals sense beneficial microbes remains poorly understood. The roundworm Caenorhabditis elegans is a microbivore that must distinguish nutritive microbes from pathogens. We characterized a neural circuit used by C. elegans to rapidly discriminate between nutritive bacteria and pathogens. Distinct sensory neuron populations responded to chemical cues from nutritive Escherichia coli and pathogenic Enterococcus faecalis, and these neural signals are decoded by downstream AIB interneurons. The polyamine metabolites cadaverine, putrescine, and spermidine produced by E. coli activate this neural circuit and elicit positive chemotaxis. Our study shows how polyamine odorants can be sensed by animals as proxies for microbe identity and suggests that, hence, polyamines might have widespread roles brokering host-microbe interactions.
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Affiliation(s)
- Benjamin Brissette
- Department of Cell Biology, Neuroscience and Physiology, Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
| | - Lia Ficaro
- Department of Biochemistry and Pharmacology, NYU School of Medicine, New York, NY 10016, USA
| | - Chenguang Li
- Biophysics Program, Harvard University, Cambridge, MA 02138, USA
| | - Drew R. Jones
- Department of Biochemistry and Pharmacology, NYU School of Medicine, New York, NY 10016, USA
| | - Sharad Ramanathan
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Niels Ringstad
- Department of Cell Biology, Neuroscience and Physiology, Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
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3
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Ma F, Lau CY, Zheng C. Young duplicate genes show developmental stage- and cell type-specific expression and function in Caenorhabditis elegans. CELL GENOMICS 2024; 4:100467. [PMID: 38190105 PMCID: PMC10794840 DOI: 10.1016/j.xgen.2023.100467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/06/2023] [Accepted: 11/23/2023] [Indexed: 01/09/2024]
Abstract
Gene duplication produces the material that fuels evolutionary innovation. The "out-of-testis" hypothesis suggests that sperm competition creates selective pressure encouraging the emergence of new genes in male germline, but the somatic expression and function of the newly evolved genes are not well understood. We systematically mapped the expression of young duplicate genes throughout development in Caenorhabditis elegans using both whole-organism and single-cell transcriptomic data. Based on the expression dynamics across developmental stages, young duplicate genes fall into three clusters that are preferentially expressed in early embryos, mid-stage embryos, and late-stage larvae. Early embryonic genes are involved in protein degradation and develop essentiality comparable to the genomic average. In mid-to-late embryos and L4-stage larvae, young genes are enriched in intestine, epidermal cells, coelomocytes, and amphid chemosensory neurons. Their molecular functions and inducible expression indicate potential roles in innate immune response and chemosensory perceptions, which may contribute to adaptation outside of the sperm.
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Affiliation(s)
- Fuqiang Ma
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Chun Yin Lau
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Chaogu Zheng
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
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4
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Gat A, Pechuk V, Peedikayil-Kurien S, Karimi S, Goldman G, Sela S, Lubliner J, Krieg M, Oren-Suissa M. Integration of spatially opposing cues by a single interneuron guides decision-making in C. elegans. Cell Rep 2023; 42:113075. [PMID: 37691148 DOI: 10.1016/j.celrep.2023.113075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 07/11/2023] [Accepted: 08/16/2023] [Indexed: 09/12/2023] Open
Abstract
The capacity of animals to respond to hazardous stimuli in their surroundings is crucial for their survival. In mammals, complex evaluations of the environment require large numbers and different subtypes of neurons. The nematode C. elegans avoids hazardous chemicals they encounter by reversing their direction of movement. How does the worms' compact nervous system process the spatial information and direct motion change? We show here that a single interneuron, AVA, receives glutamatergic excitatory and inhibitory signals from head and tail sensory neurons, respectively. AVA integrates the spatially distinct and opposing cues, whose output instructs the animal's behavioral decision. We further find that the differential activation of AVA stems from distinct localization of inhibitory and excitatory glutamate-gated receptors along AVA's process and from different threshold sensitivities of the sensory neurons. Our results thus uncover a cellular mechanism that mediates spatial computation of nociceptive cues for efficient decision-making in C. elegans.
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Affiliation(s)
- Asaf Gat
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Vladyslava Pechuk
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sonu Peedikayil-Kurien
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Shadi Karimi
- Neurophotonics and Mechanical Systems Biology, ICFO (Institut de Ciencies Fot'oniques), The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Gal Goldman
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sapir Sela
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Jazz Lubliner
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michael Krieg
- Neurophotonics and Mechanical Systems Biology, ICFO (Institut de Ciencies Fot'oniques), The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Meital Oren-Suissa
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel.
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5
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Mingjie Y, Yair A, Tali G. The RIDD activity of C. elegans IRE1 modifies neuroendocrine signaling in anticipation of environment stress to ensure survival. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552841. [PMID: 37609168 PMCID: PMC10441387 DOI: 10.1101/2023.08.10.552841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Xbp1 splicing and regulated IRE1-dependent RNA decay (RIDD) are two RNase activities of the ER stress sensor IRE1. While Xbp1 splicing has important roles in stress responses and animal physiology, the physiological role(s) of RIDD remain enigmatic. Genetic evidence in C. elegans connects XBP1-independent IRE1 activity to organismal stress adaptation, but whether this is via RIDD, and what are the targets is yet unknown. We show that cytosolic kinase/RNase domain of C. elegans IRE1 is indeed capable of RIDD in human cells, and that sensory neurons use RIDD to signal environmental stress, by degrading mRNA of TGFβ-like growth factor DAF-7. daf-7 was degraded in human cells by both human and worm IRE1 RNAse activity with same efficiency and specificity as Blos1, confirming daf-7 as RIDD substrate. Surprisingly, daf-7 degradation in vivo was triggered by concentrations of ER stressor tunicamycin too low for xbp-1 splicing. Decrease in DAF-7 normally signals food limitation and harsh environment, triggering adaptive changes to promote population survival. Because C. elegans is a bacteriovore, and tunicamycin, like other common ER stressors, is an antibiotic secreted by Streptomyces spp., we asked whether daf-7 degradation by RIDD could signal pending food deprivation. Indeed, pre-emptive tunicamycin exposure increased survival of C. elegans populations under food limiting/high temperature stress, and this protection was abrogated by overexpression of DAF-7. Thus, C. elegans uses stress-inducing metabolites in its environment as danger signals, and employs IRE1's RIDD activity to modulate the neuroendocrine signaling for survival of upcoming environmental challenge.
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Affiliation(s)
- Ying Mingjie
- Department of Biology, Drexel University, Philadelphia, PA
- Department of Pathology and Lab Medicine, The Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, PA, USA
| | - Argon Yair
- Department of Pathology and Lab Medicine, The Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, PA, USA
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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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Maushe D, Ogi V, Divakaran K, Verdecia Mogena AM, Himmighofen PA, Machado RAR, Towbin BD, Ehlers RU, Molina C, Parisod C, Maud Robert CA. Stress tolerance in entomopathogenic nematodes: Engineering superior nematodes for precision agriculture. J Invertebr Pathol 2023:107953. [PMID: 37336478 DOI: 10.1016/j.jip.2023.107953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 06/21/2023]
Abstract
Entomopathogenic nematodes (EPNs) are soil-dwelling parasitic roundworms commonly used as biocontrol agents of insect pests in agriculture. EPN dauer juveniles locate and infect a host in which they will grow and multiply until resource depletion. During their free-living stage, EPNs face a series of internal and environmental stresses. Their ability to overcome these challenges is crucial to determine their infection success and survival. In this review, we provide a comprehensive overview of EPN response to stresses associated with starvation, low/elevated temperatures, desiccation, osmotic stress, hypoxia, and ultra-violet light. We further report EPN defense strategies to cope with biotic stressors such as viruses, bacteria, fungi, and predatory insects. By comparing the genetic and biochemical basis of these strategies to the nematode model Caenorhabditis elegans, we provide new avenues and targets to select and engineer precision nematodes adapted to specific field conditions.
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Affiliation(s)
- Dorothy Maushe
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Vera Ogi
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Keerthi Divakaran
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | | | - Paul Anton Himmighofen
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Ricardo A R Machado
- Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Benjamin Daniel Towbin
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, CH-3012 Bern, Switzerland
| | - Ralf-Udo Ehlers
- e- nema GmbH, Klausdorfer Str. 28-36, DE-24223 Schwentinental, Germany
| | - Carlos Molina
- e- nema GmbH, Klausdorfer Str. 28-36, DE-24223 Schwentinental, Germany
| | - Christian Parisod
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Christelle Aurélie Maud Robert
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Hochschulstrasse 4, CH-3012 Bern, Switzerland.
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8
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Chaubey AH, Sojka SE, Onukwufor JO, Ezak MJ, Vandermeulen MD, Bowitch A, Vodičková A, Wojtovich AP, Ferkey DM. The Caenorhabditis elegans innexin INX-20 regulates nociceptive behavioral sensitivity. Genetics 2023; 223:iyad017. [PMID: 36753530 PMCID: PMC10319955 DOI: 10.1093/genetics/iyad017] [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: 09/03/2022] [Revised: 09/03/2022] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Organisms rely on chemical cues in their environment to indicate the presence or absence of food, reproductive partners, predators, or other harmful stimuli. In the nematode Caenorhabditis elegans, the bilaterally symmetric pair of ASH sensory neurons serves as the primary nociceptors. ASH activation by aversive stimuli leads to backward locomotion and stimulus avoidance. We previously reported a role for guanylyl cyclases in dampening nociceptive sensitivity that requires an innexin-based gap junction network to pass cGMP between neurons. Here, we report that animals lacking function of the gap junction component INX-20 are hypersensitive in their behavioral response to both soluble and volatile chemical stimuli that signal through G protein-coupled receptor pathways in ASH. We find that expressing inx-20 in the ADL and AFD sensory neurons is sufficient to dampen ASH sensitivity, which is supported by new expression analysis of endogenous INX-20 tagged with mCherry via the CRISPR-Cas9 system. Although ADL does not form gap junctions directly with ASH, it does so via gap junctions with the interneuron RMG and the sensory neuron ASK. Ablating either ADL or RMG and ASK also resulted in nociceptive hypersensitivity, suggesting an important role for RMG/ASK downstream of ADL in the ASH modulatory circuit. This work adds to our growing understanding of the repertoire of ways by which ASH activity is regulated via its connectivity to other neurons and identifies a previously unknown role for ADL and RMG in the modulation of aversive behavior.
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Affiliation(s)
- Aditi H Chaubey
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Savannah E Sojka
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - John O Onukwufor
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Meredith J Ezak
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Matthew D Vandermeulen
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Alexander Bowitch
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Anežka Vodičková
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Andrew P Wojtovich
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
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9
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Cronobacter sakazakii Cue for the Attraction and Its Impact on the Immunity of Caenorhabditis elegans. Infect Immun 2022; 90:e0028122. [PMID: 36377894 PMCID: PMC9753658 DOI: 10.1128/iai.00281-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Cronobacter sakazakii, an opportunistic foodborne pathogen prevalently detected in contaminated powdered infant formula, is associated with different diseases, including meningitis. It can cross the blood-brain barrier and affects the CNS. The impact of C. sakazakii on host neuronal cells and behavior is largely unknown. Hence, detailed molecular data are required to understand its severity. Caenorhabditis elegans is a unique model for studying chemical communication, as it relies on chemosensation for searching nutritional supplements. Although, C. sakazakii is pathogenic to C. elegans, our analysis indicated that C. elegans was highly attracted toward C. sakazakii compared to its food source, E. coli OP50. To study the cue for the attraction, bioactive components (RNA/Protein/Lipopolysaccharides/Metabolites) of C. sakazakii were isolated and used for observing the chemotaxis behavior of C. elegans. The results signified that C. elegans was more attracted toward acid extracted metabolites than those of the other extraction methods. The combined action of acid extracted metabolites of C. sakazakii and a candidate pathogen drastically reduced the survival of C. elegans. In addition, qPCR analysis suggested that the exposure of isolated metabolites through acid extraction to C. elegans for 24 h modified the candidate immune regulatory genes involved in pathogen recognition and kinase activity such as clec-60, clec-87, lys-7, akt-2, pkc-1, and jnk-1.
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10
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Yoon KH, Indong RA, Lee JI. Making "Sense" of Ecology from a Genetic Perspective: Caenorhabditis elegans, Microbes and Behavior. Metabolites 2022; 12:1084. [PMID: 36355167 PMCID: PMC9697003 DOI: 10.3390/metabo12111084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/02/2022] [Accepted: 11/05/2022] [Indexed: 12/31/2023] Open
Abstract
Our knowledge of animal and behavior in the natural ecology is based on over a century's worth of valuable field studies. In this post-genome era, however, we recognize that genes are the underpinning of ecological interactions between two organisms. Understanding how genes contribute to animal ecology, which is essentially the intersection of two genomes, is a tremendous challenge. The bacterivorous nematode Caenorhabditis elegans, one of the most well-known genetic animal model experimental systems, experiences a complex microbial world in its natural habitat, providing us with a window into the interplay of genes and molecules that result in an animal-microbial ecology. In this review, we will discuss C. elegans natural ecology, how the worm uses its sensory system to detect the microbes and metabolites that it encounters, and then discuss some of the fascinating ecological dances, including behaviors, that have evolved between the nematode and the microbes in its environment.
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Affiliation(s)
- Kyoung-hye Yoon
- Department of Physiology, Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju 26426, Korea
| | - Rocel Amor Indong
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Wonju 26493, Korea
| | - Jin I. Lee
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Wonju 26493, Korea
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11
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Filipowicz A, Lalsiamthara J, Aballay A. Dissection of a sensorimotor circuit underlying pathogen aversion in C. elegans. BMC Biol 2022; 20:229. [PMID: 36209082 PMCID: PMC9548130 DOI: 10.1186/s12915-022-01424-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/28/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Altering animal behavior to reduce pathogen exposure is a key line of defense against pathogen attack. In Caenorhabditis elegans, alterations in intestinal physiology caused by pathogen colonization and sensation of microbial metabolites may lead to activation of pathogen aversive behaviors ranging from aversive reflexes to learned avoidance. However, the neural circuitry between chemosensory neurons that sense pathogenic bacterial cues and the motor neurons responsible for avoidance-associated locomotion remains unknown. RESULTS Using C. elegans, we found that backward locomotion was a component of learned pathogen avoidance, as animals pre-exposed to Pseudomonas aeruginosa or Enterococcus faecalis showed reflexive aversion to drops of the bacteria driven by chemosensory neurons, including the olfactory AWB neurons. This response also involved intestinal distention and, for E. faecalis, required expression of TRPM channels in the intestine and excretory system. Additionally, we uncovered a circuit composed of olfactory neurons, interneurons, and motor neurons that controls the backward locomotion crucial for learned reflexive aversion to pathogenic bacteria, learned avoidance, and the repulsive odor 2-nonanone. CONCLUSIONS Using whole-brain simulation and functional assays, we uncovered a novel sensorimotor circuit governing learned reflexive aversion. The discovery of a complete sensorimotor circuit for reflexive aversion demonstrates the utility of using the C. elegans connectome and computational modeling in uncovering new neuronal regulators of behavior.
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Affiliation(s)
- Adam Filipowicz
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA
- Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Jonathan Lalsiamthara
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Alejandro Aballay
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA.
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12
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van Krugten J, Danné N, Peterman EJG. A local interplay between diffusion and intraflagellar transport distributes TRPV-channel OCR-2 along C. elegans chemosensory cilia. Commun Biol 2022; 5:720. [PMID: 35858995 PMCID: PMC9300729 DOI: 10.1038/s42003-022-03683-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 07/06/2022] [Indexed: 02/07/2023] Open
Abstract
To survive, Caenorhabditis elegans depends on sensing soluble chemicals with transmembrane proteins (TPs) in the cilia of its chemosensory neurons. Cilia rely on intraflagellar transport (IFT) to facilitate the distribution of cargo, such as TPs, along the ciliary axoneme. Here, we use fluorescence imaging of living worms and perform single-molecule tracking experiments to elucidate the dynamics underlying the ciliary distribution of the sensory TP OCR-2. Quantitative analysis reveals that the ciliary distribution of OCR-2 depends on an intricate interplay between transport modes that depends on the specific location in the cilium: in dendrite and transition zone, directed transport is predominant. Along the cilium motion is mostly due to normal diffusion together with a small fraction of directed transport, while at the ciliary tip subdiffusion dominates. These insights in the role of IFT and diffusion in ciliary dynamics contribute to a deeper understanding of ciliary signal transduction and chemosensing.
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Affiliation(s)
- Jaap van Krugten
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan, 1081 HV, Amsterdam, The Netherlands
| | - Noémie Danné
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan, 1081 HV, Amsterdam, The Netherlands
| | - Erwin J G Peterman
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan, 1081 HV, Amsterdam, The Netherlands.
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13
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Zaroubi L, Ozugergin I, Mastronardi K, Imfeld A, Law C, Gélinas Y, Piekny A, Findlay BL. The Ubiquitous Soil Terpene Geosmin Acts as a Warning Chemical. Appl Environ Microbiol 2022; 88:e0009322. [PMID: 35323022 PMCID: PMC9004350 DOI: 10.1128/aem.00093-22] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/26/2022] [Indexed: 12/29/2022] Open
Abstract
Known as the smell of earth after rain, geosmin is an odorous terpene detectable by humans at picomolar concentrations. Geosmin production is heavily conserved in actinobacteria, myxobacteria, cyanobacteria, and some fungi, but its biological activity is poorly understood. We theorized that geosmin was an aposematic signal used to indicate the unpalatability of toxin-producing microbes, discouraging predation by eukaryotes. Consistent with this hypothesis, we found that geosmin altered the behavior of the bacteriophagous nematode Caenorhabditis elegans on agar plates in the absence of bacteria. Normal movement was restored in mutant worms lacking differentiated ASE (amphid neurons, single ciliated endings) neurons, suggesting that geosmin is a taste detected by the nematodal gustatory system. In a predation assay, geosmin and the related terpene 2-methylisoborneol reduced grazing on the bacterium Streptomyces coelicolor. Predation was restored by the removal of both terpene biosynthetic pathways or the introduction of C. elegans that lacked differentiated ASE taste neurons, leading to the apparent death of both bacteria and worms. While geosmin and 2-methylisoborneol appeared to be nontoxic, grazing triggered bacterial sporulation and the production of actinorhodin, a pigment coproduced with a number of toxic metabolites. In this system, geosmin thus appears to act as a warning signal indicating the unpalatability of its producers and reducing predation in a manner that benefits predator and prey. This suggests that molecular signaling may affect microbial predator-prey interactions in a manner similar to that of the well-studied visual markers of poisonous animal prey. IMPORTANCE One of the key chemicals that give soil its earthy aroma, geosmin is a frequent water contaminant produced by a range of unrelated microbes. Many animals, including humans, are able to detect geosmin at minute concentrations, but the benefit that this compound provides to its producing organisms is poorly understood. We found that geosmin repelled the bacterial predator Caenorhabditis elegans in the absence of bacteria and reduced contact between the worms and the geosmin-producing bacterium Streptomyces coelicolor in a predation assay. While geosmin itself appears to be nontoxic to C. elegans, these bacteria make a wide range of toxic metabolites, and grazing on them harmed the worms. In this system, geosmin thus appears to indicate unpalatable bacteria, reducing predation and benefiting both predator and prey. Aposematic signals are well known in animals, and this work suggests that metabolites may play a similar role in the microbial world.
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Affiliation(s)
- Liana Zaroubi
- Department of Chemistry and Biochemistry, Concordia University, Montreal, Québec, Canada
| | - Imge Ozugergin
- Department of Biology, Concordia University, Montreal, Québec, Canada
| | | | - Anic Imfeld
- Department of Chemistry and Biochemistry, Concordia University, Montreal, Québec, Canada
| | - Chris Law
- Department of Biology, Concordia University, Montreal, Québec, Canada
| | - Yves Gélinas
- Department of Chemistry and Biochemistry, Concordia University, Montreal, Québec, Canada
| | - Alisa Piekny
- Department of Biology, Concordia University, Montreal, Québec, Canada
| | - Brandon L. Findlay
- Department of Chemistry and Biochemistry, Concordia University, Montreal, Québec, Canada
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14
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Abergel Z, Shaked M, Shukla V, Wu ZX, Gross E. The phosphatidylinositol transfer protein PITP-1 facilitates fast recovery of eating behavior after hypoxia in the nematode Caenorhabditis elegans. FASEB J 2021; 35:e21202. [PMID: 33368638 PMCID: PMC7839455 DOI: 10.1096/fj.202000704r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 10/21/2020] [Accepted: 11/03/2020] [Indexed: 12/18/2022]
Abstract
Among the fascinating adaptations to limiting oxygen conditions (hypoxia) is the suppression of food intake and weight loss. In humans, this phenomenon is called high-altitude anorexia and is observed in people suffering from acute mountain syndrome. The high-altitude anorexia appears to be conserved in evolution and has been seen in species across the animal kingdom. However, the mechanism underlying the recovery of eating behavior after hypoxia is still not known. Here, we show that the phosphatidylinositol transfer protein PITP-1 is essential for the fast recovery of eating behavior after hypoxia in the nematode Caenorhabditis elegans. Unlike the neuroglobin GLB-5 that accelerates the recovery of eating behavior through its function in the oxygen (O2 )-sensing neurons, PITP-1 appears to act downstream, in neurons that express the mod-1 serotonin receptor. Indeed, pitp-1 mutants display wild-type-like O2 -evoked-calcium responses in the URX O2 -sensing neuron. Intriguingly, loss-of-function of protein kinase C 1 (PKC-1) rescues pitp-1 mutants' recovery after hypoxia. Increased diacylglycerol (DAG), which activates PKC-1, attenuates the recovery of wild-type worms. Together, these data suggest that PITP-1 enables rapid recovery of eating behavior after hypoxia by limiting DAG's availability, thereby limiting PKC activity in mod-1-expressing neurons.
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Affiliation(s)
- Zohar Abergel
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, IMRIC, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maayan Shaked
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, IMRIC, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Virendra Shukla
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, IMRIC, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Zheng-Xing Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Institute of Biophysics and Biochemistry, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Einav Gross
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, IMRIC, The Hebrew University of Jerusalem, Jerusalem, Israel
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15
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Filipowicz A, Lalsiamthara J, Aballay A. TRPM channels mediate learned pathogen avoidance following intestinal distention. eLife 2021; 10:65935. [PMID: 34032213 PMCID: PMC8177887 DOI: 10.7554/elife.65935] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 05/24/2021] [Indexed: 12/13/2022] Open
Abstract
Upon exposure to harmful microorganisms, hosts engage in protective molecular and behavioral immune responses, both of which are ultimately regulated by the nervous system. Using the nematode Caenorhabditis elegans, we show that ingestion of Enterococcus faecalis leads to a fast pathogen avoidance behavior that results in aversive learning. We have identified multiple sensory mechanisms involved in the regulation of avoidance of E. faecalis. The G-protein coupled receptor NPR-1-dependent oxygen-sensing pathway opposes this avoidance behavior, while an ASE neuron-dependent pathway and an AWB and AWC neuron-dependent pathway are directly required for avoidance. Colonization of the anterior part of the intestine by E. faecalis leads to AWB and AWC mediated olfactory aversive learning. Finally, two transient receptor potential melastatin (TRPM) channels, GON-2 and GTL-2, mediate this newly described rapid pathogen avoidance. These results suggest a mechanism by which TRPM channels may sense the intestinal distension caused by bacterial colonization to elicit pathogen avoidance and aversive learning by detecting changes in host physiology.
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Affiliation(s)
- Adam Filipowicz
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, United States
| | - Jonathan Lalsiamthara
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, United States
| | - Alejandro Aballay
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, United States
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16
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Wibisono P, Sun J. Neuro-immune communication in C. elegans defense against pathogen infection. CURRENT RESEARCH IN IMMUNOLOGY 2021; 2:60-65. [PMID: 34368754 PMCID: PMC8344176 DOI: 10.1016/j.crimmu.2021.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The innate immune system is a complex collection of physical barriers and physiological defense responses to internal and external environmental assaults. Recent studies in the model organism Caenorhabditis elegans have highlighted how the nervous system interacts with the innate immune system to generate coordinated protective responses. Indeed, studies on neuro-immune interaction pathways have provided mechanistic insights into the roles of neuro-immune communication in modulating both immune and behavioral responses to pathogen attacks. The nervous system releases a variety of neurotransmitters, peptides, and hormones that regulate the innate immune response, while the innate immune system also relays information to the nervous system to affect learning and behavioral responses. Although these interactions still need further investigation, the knowledge that we have gained thus far has improved our understanding of how separate biological systems can act collectively for the survival and well-being of an organism. Here, we review recent studies on neuro-immune communication related to the survival and defense of C. elegans against pathogens. Neuro-immune communication is essential for generating coordinated defense against pathogen infection to improve host survival. Neuro-immune communication modulates both immune and behavioral responses to pathogen attacks. C.elegans is an excellent model system for studying neuro-immune communication.
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Affiliation(s)
- Phillip Wibisono
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Jingru Sun
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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17
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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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18
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Abstract
Although Caenorhabditis elegans has been used as a model host for studying host-pathogen interactions for more than 20 years, the mechanisms by which it identifies pathogens are not well understood. This is largely due to its lack of most known pattern recognition receptors (PRRs) that recognize pathogen-derived molecules. Recent behavioral research in C. elegans indicates that its nervous system plays a major role in microbe sensing. With the increasing integration of neurobiology in immunological research, future studies may find that neuronal detection of pathogens is an integral part of C. elegans-pathogen interactions. Similar to that of mammals, the C. elegans nervous system regulates its immune system to maintain immunological homeostasis. Studies in the nematode have revealed unprecedented details regarding the molecules, cells, and signaling pathways involved in neural regulation of immunity. Notably, some of the studies indicate that some neuroimmune regulatory circuits need not be "activated" by pathogen infection because they are tonically active and that there could be a predetermined set point for internal immunity, around which the nervous system adjusts immune responses to internal or external environmental changes. Here, we review recent progress on the roles of the C. elegans nervous system in pathogen detection and immune regulation. Because of its advantageous characteristics, we expect that the C. elegans model will be critical for deciphering complex neuroimmune signaling mechanisms that integrate and process multiple sensory cues.
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Affiliation(s)
- Yiyong Liu
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, USA
- Genomics Core, Washington State University, Spokane, Washington, USA
| | - Jingru Sun
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, USA
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19
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Abstract
In its natural habitat, C. elegans encounters a wide variety of microbes, including food, commensals and pathogens. To be able to survive long enough to reproduce, C. elegans has developed a complex array of responses to pathogens. These activities are coordinated on scales that range from individual organelles to the entire organism. Often, the response is triggered within cells, by detection of infection-induced damage, mainly in the intestine or epidermis. C. elegans has, however, a capacity for cell non-autonomous regulation of these responses. This frequently involves the nervous system, integrating pathogen recognition, altering host biology and governing avoidance behavior. Although there are significant differences with the immune system of mammals, some mechanisms used to limit pathogenesis show remarkable phylogenetic conservation. The past 20 years have witnessed an explosion of host-pathogen interaction studies using C. elegans as a model. This review will discuss the broad themes that have emerged and highlight areas that remain to be fully explored.
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Affiliation(s)
- Céline N Martineau
- Aix Marseille Université, Inserm, CNRS, CIML, Turing Centre for Living Systems, Marseille, France
| | | | - Nathalie Pujol
- Aix Marseille Université, Inserm, CNRS, CIML, Turing Centre for Living Systems, Marseille, France.
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20
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Abstract
With a nervous system that has only a few hundred neurons, Caenorhabditis elegans was initially not regarded as a model for studies on learning. However, the collective effort of the C. elegans field in the past several decades has shown that the worm displays plasticity in its behavioral response to a wide range of sensory cues in the environment. As a bacteria-feeding worm, C. elegans is highly adaptive to the bacteria enriched in its habitat, especially those that are pathogenic and pose a threat to survival. It uses several common forms of behavioral plasticity that last for different amounts of time, including imprinting and adult-stage associative learning, to modulate its interactions with pathogenic bacteria. Probing the molecular, cellular and circuit mechanisms underlying these forms of experience-dependent plasticity has identified signaling pathways and regulatory insights that are conserved in more complex animals.
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Affiliation(s)
- He Liu
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
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21
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How Bacteria Impact Host Nervous System and Behaviors: Lessons from Flies and Worms. Trends Neurosci 2020; 43:998-1010. [PMID: 33051027 DOI: 10.1016/j.tins.2020.09.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/01/2020] [Accepted: 09/16/2020] [Indexed: 12/12/2022]
Abstract
Behavior is the neuronally controlled, voluntary or involuntary response of an organism to its environment. An increasing body of evidence indicates that microbes, which live closely associated with animals or in their immediate surroundings, significantly influence animals' behavior. The extreme complexity of the nervous system of animals, combined with the extraordinary microbial diversity, are two major obstacles to understand, at the molecular level, how microbes modulate animal behavior. In this review, we discuss recent advances in dissecting the impact that bacteria have on the nervous system of two genetically tractable invertebrate models, Drosophila melanogaster and Caenorhabditis elegans.
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22
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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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23
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Wheeler NJ, Heimark ZW, Airs PM, Mann A, Bartholomay LC, Zamanian M. Genetic and functional diversification of chemosensory pathway receptors in mosquito-borne filarial nematodes. PLoS Biol 2020; 18:e3000723. [PMID: 32511224 PMCID: PMC7302863 DOI: 10.1371/journal.pbio.3000723] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 06/18/2020] [Accepted: 05/20/2020] [Indexed: 12/25/2022] Open
Abstract
Lymphatic filariasis (LF) afflicts over 60 million people worldwide and leads to severe pathological outcomes in chronic cases. The nematode parasites (Nematoda: Filarioidea) that cause LF require both arthropod (mosquito) intermediate hosts and mammalian definitive hosts for their propagation. The invasion and migration of filarial worms through host tissues are complex and critical to survival, yet little is known about the receptors and signaling pathways that mediate directed migration in these medically important species. In order to better understand the role of chemosensory signaling in filarial worm taxis, we employ comparative genomics, transcriptomics, reverse genetics, and chemical approaches to identify putative chemosensory receptor proteins and perturb chemotaxis phenotypes in filarial worms. We find that chemoreceptor family size is correlated with the presence of environmental (extrahost) stages in nematode life cycles, and that filarial worms contain compact and highly diverged chemoreceptor complements and lineage-specific ion channels that are predicted to operate downstream of chemoreceptor activation. In Brugia malayi, an etiological agent of LF, chemoreceptor expression patterns correspond to distinct parasite migration events across the life cycle. To interrogate the role of chemosensation in the migration of larval worms, arthropod and mammalian infectious stage Brugia parasites were incubated in nicotinamide, an agonist of the nematode transient receptor potential (TRP) channel OSM-9. Exposure of microfilariae to nicotinamide alters intramosquito migration, and exposure of L3s reduces chemotaxis toward host-associated cues in vitro. Nicotinamide also potently modulates thermosensory responses in L3s, suggesting a polymodal sensory role for Brugia osm-9. Reverse genetic studies implicate both Brugia osm-9 and the cyclic nucleotide-gated (CNG) channel subunit tax-4 in larval chemotaxis toward host serum, and these ion channel subunits partially rescue sensory defects in Caenorhabditis elegans osm-9 and tax-4 knock-out strains. Together, these data reveal genetic and functional diversification of chemosensory signaling proteins in filarial worms and encourage a more thorough investigation of clade- and parasite-specific facets of nematode sensory receptor biology.
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Affiliation(s)
- Nicolas J. Wheeler
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Zachary W. Heimark
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Paul M. Airs
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Alexis Mann
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Lyric C. Bartholomay
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Mostafa Zamanian
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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24
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Singh J, Aballay A. Bacterial Lawn Avoidance and Bacterial Two Choice Preference Assays in Caenorhabditis elegans. Bio Protoc 2020; 10:e3623. [PMID: 33659296 DOI: 10.21769/bioprotoc.3623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/27/2020] [Accepted: 04/15/2020] [Indexed: 11/02/2022] Open
Abstract
Physical avoidance of pathogens is a crucial defense strategy used by the host to reduce pathogen infection. Hosts display the use of multiple strategies to sense and avoid pathogens, ranging from olfaction to sensing of damage caused by pathogen infection. Understanding various mechanisms of pathogen avoidance has the potential to uncover conserved host defense responses that are important against pathogen infections. Here, we describe protocols for studying pathogen lawn avoidance behavior as well as a change of bacterial preferences in the model nematode Caenorhabditis elegans. Besides, we describe the protocol for measuring preferences for pathogenic and nonpathogenic bacteria after training of the animals on pathogenic bacteria. These assays can be implemented in discovering various mechanisms of host learning that result in the avoidance of pathogens.
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Affiliation(s)
- Jogender Singh
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - Alejandro Aballay
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon, USA
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25
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Wu S, Gao S, Wang S, Meng J, Wickham J, Luo S, Tan X, Yu H, Xiang Y, Hu S, Zhao L, Sun J. A Reference Genome of Bursaphelenchus mucronatus Provides New Resources for Revealing Its Displacement by Pinewood Nematode. Genes (Basel) 2020; 11:genes11050570. [PMID: 32438771 PMCID: PMC7288286 DOI: 10.3390/genes11050570] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/20/2020] [Accepted: 05/08/2020] [Indexed: 12/19/2022] Open
Abstract
The Bursaphelenchus mucronatus, which was highly similar with Bursaphelenchus xylophilus in terms of morphological characteristics and biological properties—but had weaker pathogenicity to forests—was a native species often displaced by B. xylophilus when occupying the same niche. Since the draft genome of the invasive B. xylophilus has been published, the absence of a reference genome of B. mucronatus still prevents us from understanding the molecular evidences behind competitive displacement. In this study, we employed Single Molecule, Real-Time (SMRT) sequencing and a Hi-C scaffolding approach to yield a near chromosome-level assembly of B. mucronatus, including six pseudo-chromosomes. The assembly size is 73 Mb, with scaffold N50 of 11.50 Mb and contig N50 of 1.48 Mb. Comparative genomics results showed high similarity between B. xylophilus and B. mucronatus. However, the losing of orphan genes and species-specific orthologous genes in B. mucronatus may indicate weaker adaptability to the environment. The gene family contractions of GPCRs (G Protein-Coupled Receptors) and cellulases in B. mucronatus may jointly contribute to its displacement by B. xylophilus. Overall, we introduced a valuable genomic resource for molecular and evolutionary studies of B. mucronatus, especially for studying the competitive displacement by the pinewood nematode, which could help us control the pathogenicity of pine wilt diseases.
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Affiliation(s)
- Shuangyang Wu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (S.W.); (J.M.); (J.W.); (Y.X.); (L.Z.)
| | - Shenghan Gao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (S.G.); (S.W.); (S.L.); (X.T.); (H.Y.); (S.H.)
| | - Sen Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (S.G.); (S.W.); (S.L.); (X.T.); (H.Y.); (S.H.)
| | - Jie Meng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (S.W.); (J.M.); (J.W.); (Y.X.); (L.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jacob Wickham
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (S.W.); (J.M.); (J.W.); (Y.X.); (L.Z.)
| | - Sainan Luo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (S.G.); (S.W.); (S.L.); (X.T.); (H.Y.); (S.H.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinyu Tan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (S.G.); (S.W.); (S.L.); (X.T.); (H.Y.); (S.H.)
| | - Haiying Yu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (S.G.); (S.W.); (S.L.); (X.T.); (H.Y.); (S.H.)
| | - Yujia Xiang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (S.W.); (J.M.); (J.W.); (Y.X.); (L.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Songnian Hu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (S.G.); (S.W.); (S.L.); (X.T.); (H.Y.); (S.H.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lilin Zhao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (S.W.); (J.M.); (J.W.); (Y.X.); (L.Z.)
| | - Jianghua Sun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (S.W.); (J.M.); (J.W.); (Y.X.); (L.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: ; Tel.: +86-10-64807121
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26
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Becher PG, Verschut V, Bibb MJ, Bush MJ, Molnár BP, Barane E, Al-Bassam MM, Chandra G, Song L, Challis GL, Buttner MJ, Flärdh K. Developmentally regulated volatiles geosmin and 2-methylisoborneol attract a soil arthropod to Streptomyces bacteria promoting spore dispersal. Nat Microbiol 2020; 5:821-829. [DOI: 10.1038/s41564-020-0697-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 02/21/2020] [Indexed: 12/28/2022]
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27
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Singh J, Aballay A. Neural control of behavioral and molecular defenses in C. elegans. Curr Opin Neurobiol 2019; 62:34-40. [PMID: 31812835 DOI: 10.1016/j.conb.2019.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/14/2019] [Indexed: 01/22/2023]
Abstract
The nervous and immune systems use bi-directional communication to control host responses against microbial pathogens. Recent studies at the interface of the two systems have highlighted important roles of the nervous system in the regulation of both microbicidal pathways and pathogen avoidance behaviors. Studies on the neural circuits in the simple model host Caenorhabditis elegans have significantly improved our understanding of the roles of conserved neural mechanisms in controlling innate immunity. Moreover, behavioral studies have advanced our understanding of how the nervous system may sense potential pathogens and consequently elicit pathogen avoidance, reducing the risk of infection. In this review, we discuss the neural circuits that regulate both behavioral immunity and molecular immunity in C. elegans.
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Affiliation(s)
- Jogender Singh
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Alejandro Aballay
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA.
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28
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Woldemariam S, Nagpal J, Hill T, Li J, Schneider MW, Shankar R, Futey M, Varshney A, Ali N, Mitchell J, Andersen K, Barsi-Rhyne B, Tran A, Costa WS, Krzyzanowski MC, Yu YV, Brueggemann C, Hamilton OS, Ferkey DM, VanHoven M, Sengupta P, Gottschalk A, L'Etoile N. Using a Robust and Sensitive GFP-Based cGMP Sensor for Real-Time Imaging in Intact Caenorhabditis elegans. Genetics 2019; 213:59-77. [PMID: 31331946 PMCID: PMC6727795 DOI: 10.1534/genetics.119.302392] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 07/05/2019] [Indexed: 12/31/2022] Open
Abstract
cGMP plays a role in sensory signaling and plasticity by regulating ion channels, phosphodiesterases, and kinases. Studies that primarily used genetic and biochemical tools suggest that cGMP is spatiotemporally regulated in multiple sensory modalities. FRET- and GFP-based cGMP sensors were developed to visualize cGMP in primary cell culture and Caenorhabditis elegans to corroborate these findings. While a FRET-based sensor has been used in an intact animal to visualize cGMP, the requirement of a multiple emission system limits its ability to be used on its own as well as with other fluorophores. Here, we demonstrate that a C. elegans codon-optimized version of the cpEGFP-based cGMP sensor FlincG3 can be used to visualize rapidly changing cGMP levels in living, behaving C. elegans We coexpressed FlincG3 with the blue-light-activated guanylyl cyclases BeCyclOp and bPGC in body wall muscles, and found that the rate of change in FlincG3 fluorescence correlated with the rate of cGMP production by each cyclase. Furthermore, we show that FlincG3 responds to cultivation temperature, NaCl concentration changes, and sodium dodecyl sulfate in the sensory neurons AFD, ASEL/R, and PHB, respectively. Intriguingly, FlincG3 fluorescence in ASEL and ASER decreased in response to a NaCl concentration upstep and downstep, respectively, which is opposite in sign to the coexpressed calcium sensor jRGECO1a and previously published calcium recordings. These results illustrate that FlincG3 can be used to report rapidly changing cGMP levels in an intact animal, and that the reporter can potentially reveal unexpected spatiotemporal landscapes of cGMP in response to stimuli.
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Affiliation(s)
- Sarah Woldemariam
- Chemistry and Chemical Biology Graduate Program, University of California, San Francisco, California 94158
- Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
| | - Jatin Nagpal
- Department of Molecular Membrane Biology and Neurobiology, The Goethe University, 60323 Frankfurt, Germany
| | - Tyler Hill
- Neuroscience Graduate Program, Brandeis University, Waltham, Massachusetts 02453
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454
| | - Joy Li
- Department of Biological Sciences, San Jose State University, California 95192
| | - Martin W Schneider
- Department of Molecular Membrane Biology and Neurobiology, The Goethe University, 60323 Frankfurt, Germany
| | - Raakhee Shankar
- Department of Biological Sciences, San Jose State University, California 95192
| | - Mary Futey
- Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
| | - Aruna Varshney
- Department of Biological Sciences, San Jose State University, California 95192
| | - Nebat Ali
- Department of Biological Sciences, San Jose State University, California 95192
| | - Jordan Mitchell
- Department of Biological Sciences, San Jose State University, California 95192
| | - Kristine Andersen
- Department of Biological Sciences, San Jose State University, California 95192
| | | | - Alan Tran
- Department of Biological Sciences, San Jose State University, California 95192
| | - Wagner Steuer Costa
- Department of Molecular Membrane Biology and Neurobiology, The Goethe University, 60323 Frankfurt, Germany
| | - Michelle C Krzyzanowski
- Department of Biological Sciences, University at Buffalo, The State University of New York, New York 14260
| | - Yanxun V Yu
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454
| | - Chantal Brueggemann
- Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
| | - O Scott Hamilton
- Center for Neuroscience, University of California, Davis, California 95618
| | - Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, New York 14260
| | - Miri VanHoven
- Department of Biological Sciences, San Jose State University, California 95192
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454
| | - Alexander Gottschalk
- Department of Molecular Membrane Biology and Neurobiology, The Goethe University, 60323 Frankfurt, Germany
| | - Noelle L'Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
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29
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Hoffman C, Aballay A. Role of neurons in the control of immune defense. Curr Opin Immunol 2019; 60:30-36. [PMID: 31117013 DOI: 10.1016/j.coi.2019.04.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/11/2019] [Accepted: 04/12/2019] [Indexed: 11/28/2022]
Abstract
Studies in recent years have strengthened the notion that neural mechanisms are involved in the control of immune responses. From initial studies that highlighted the vagus nerve control of inflammatory responses in vertebrates, many advances have been made, including the dissection of specific neural circuits that are involved in controlling immunity. Part of this has been facilitated by the use of a tractable model animal, Caenorhabditis elegans, in which individual neurons involved in sensing pathogens and controlling the immune response have been identified. Importantly, some of the underlying mechanisms involved in the neural control of immune pathways appear to be present in evolutionarily diverse species. This review focuses on some major developments in vertebrates and C. elegans, and how these discoveries may lead to advances in understanding neural-immune connections that govern inflammatory responses.
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Affiliation(s)
- Casandra Hoffman
- Molecular Microbiology and Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, 6351 Richard Jones Hall, Mail Code: L220, Portland, OR 97239, United States
| | - Alejandro Aballay
- Molecular Microbiology and Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, 6351 Richard Jones Hall, Mail Code: L220, Portland, OR 97239, United States.
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30
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Anderson A, McMullan R. Neuronal and non-neuronal signals regulate Caernorhabditis elegans avoidance of contaminated food. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0255. [PMID: 29866922 PMCID: PMC6000145 DOI: 10.1098/rstb.2017.0255] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2017] [Indexed: 01/24/2023] Open
Abstract
One way in which animals minimize the risk of infection is to reduce their contact with contaminated food. Here, we establish a model of pathogen-contaminated food avoidance using the nematode worm Caernorhabditis elegans. We find that avoidance of pathogen-contaminated food protects C. elegans from the deleterious effects of infection and, using genetic approaches, demonstrate that multiple sensory neurons are required for this avoidance behaviour. In addition, our results reveal that the avoidance of contaminated food requires bacterial adherence to non-neuronal cells in the tail of C. elegans that are also required for the cellular immune response. Previous studies in C. elegans have contributed significantly to our understanding of molecular and cellular basis of host–pathogen interactions and our model provides a unique opportunity to gain basic insights into how animals avoid contaminated food. This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours’.
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Affiliation(s)
- Alexandra Anderson
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Rachel McMullan
- School of Life, Health and Chemical Sciences, The Open University, Milton Keynes, Buckinghamshire MK7 2AA, UK
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31
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Varshney A, Benedetti K, Watters K, Shankar R, Tatarakis D, Coto Villa D, Magallanes K, Agenor V, Wung W, Farah F, Ali N, Le N, Pyle J, Farooqi A, Kieu Z, Bremer M, VanHoven M. The receptor protein tyrosine phosphatase CLR-1 is required for synaptic partner recognition. PLoS Genet 2018; 14:e1007312. [PMID: 29742100 PMCID: PMC5942785 DOI: 10.1371/journal.pgen.1007312] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 03/19/2018] [Indexed: 11/19/2022] Open
Abstract
During neural circuit formation, most axons are guided to complex environments, coming into contact with multiple potential synaptic partners. However, it is critical that they recognize specific neurons with which to form synapses. Here, we utilize the split GFP-based marker Neuroligin-1 GFP Reconstitution Across Synaptic Partners (NLG-1 GRASP) to visualize specific synapses in live animals, and a circuit-specific behavioral assay to probe circuit function. We demonstrate that the receptor protein tyrosine phosphatase (RPTP) clr-1 is necessary for synaptic partner recognition (SPR) between the PHB sensory neurons and the AVA interneurons in C. elegans. Mutations in clr-1/RPTP result in reduced NLG-1 GRASP fluorescence and impaired behavioral output of the PHB circuit. Temperature-shift experiments demonstrate that clr-1/RPTP acts early in development, consistent with a role in SPR. Expression and cell-specific rescue experiments indicate that clr-1/RPTP functions in postsynaptic AVA neurons, and overexpression of clr-1/RPTP in AVA neurons is sufficient to direct additional PHB-AVA synaptogenesis. Genetic analysis reveals that clr-1/RPTP acts in the same pathway as the unc-6/Netrin ligand and the unc-40/DCC receptor, which act in AVA and PHB neurons, respectively. This study defines a new mechanism by which SPR is governed, and demonstrates that these three conserved families of molecules, with roles in neurological disorders and cancer, can act together to regulate communication between cells.
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Affiliation(s)
- Aruna Varshney
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Kelli Benedetti
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Katherine Watters
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Raakhee Shankar
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - David Tatarakis
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Doris Coto Villa
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Khristina Magallanes
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Venia Agenor
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - William Wung
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Fatima Farah
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Nebat Ali
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Nghi Le
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Jacqueline Pyle
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Amber Farooqi
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Zanett Kieu
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Martina Bremer
- Department of Mathematics and Statistics, San Jose State University, San Jose, CA, United States of America
| | - Miri VanHoven
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
- * E-mail:
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