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White OR, Graziano B, Bianchi L. Comparison of avoidance assay techniques to determine the response to 1-octanol in C. elegans. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001177. [PMID: 38660566 PMCID: PMC11040396 DOI: 10.17912/micropub.biology.001177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 03/27/2024] [Accepted: 04/07/2024] [Indexed: 04/26/2024]
Abstract
In C. elegans , avoidance behaviors are vital for the nematode's ability to respond to noxious environmental stimuli, including the odorant 1-octanol. To test avoidance to 1-octanol, researchers expose C. elegans to this odorant and determine the time taken to initiate backward locomotion. However, the 1-octanol avoidance assay is sensitive to sensory adaptation, where the avoidance response is reduced due to overexposure to the odorant. Here, we examined two methods to expose nematodes to 1-octanol, using an eyelash hair or a p10 pipette tip, to compare their susceptibility to cause sensory adaptation.
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Affiliation(s)
- Olivia R. White
- Physiology and Biophysics, University of Miami Health System, Miami, Florida, United States
| | - Bianca Graziano
- Physiology and Biophysics, University of Miami Health System, Miami, Florida, United States
| | - Laura Bianchi
- Physiology and Biophysics, University of Miami Health System, Miami, Florida, United States
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2
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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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3
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Le E, McCarthy T, Honer M, Curtin CE, Fingerut J, Nelson MD. The neuropeptide receptor npr-38 regulates avoidance and stress-induced sleep in Caenorhabditis elegans. Curr Biol 2023; 33:3155-3168.e9. [PMID: 37419114 DOI: 10.1016/j.cub.2023.06.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 05/19/2023] [Accepted: 06/14/2023] [Indexed: 07/09/2023]
Abstract
Although essential and conserved, sleep is not without its challenges that must be overcome; most notably, it renders animals vulnerable to threats in the environment. Infection and injury increase sleep demand, which dampens sensory responsiveness to stimuli, including those responsible for the initial insult. Stress-induced sleep in Caenorhabditis elegans occurs in response to cellular damage following noxious exposures the animals attempted to avoid. Here, we describe a G-protein-coupled receptor (GPCR) encoded by npr-38, which is required for stress-related responses including avoidance, sleep, and arousal. Overexpression of npr-38 shortens the avoidance phase and causes animals to initiate movement quiescence and arouse early. npr-38 functions in the ADL sensory neurons, which express neuropeptides encoded by nlp-50, also required for movement quiescence. npr-38 regulates arousal by acting on the DVA and RIS interneurons. Our work demonstrates that this single GPCR regulates multiple aspects of the stress response by functioning in sensory and sleep interneurons.
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Affiliation(s)
- Emily Le
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Teagan McCarthy
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Madison Honer
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Caroline E Curtin
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Jonathan Fingerut
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Matthew D Nelson
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA.
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4
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Brocal-Ruiz R, Esteve-Serrano A, Mora-Martínez C, Franco-Rivadeneira ML, Swoboda P, Tena JJ, Vilar M, Flames N. Forkhead transcription factor FKH-8 cooperates with RFX in the direct regulation of sensory cilia in Caenorhabditis elegans. eLife 2023; 12:e89702. [PMID: 37449480 PMCID: PMC10393296 DOI: 10.7554/elife.89702] [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: 05/26/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023] Open
Abstract
Cilia, either motile or non-motile (a.k.a primary or sensory), are complex evolutionarily conserved eukaryotic structures composed of hundreds of proteins required for their assembly, structure and function that are collectively known as the ciliome. Ciliome gene mutations underlie a group of pleiotropic genetic diseases known as ciliopathies. Proper cilium function requires the tight coregulation of ciliome gene transcription, which is only fragmentarily understood. RFX transcription factors (TF) have an evolutionarily conserved role in the direct activation of ciliome genes both in motile and non-motile cilia cell-types. In vertebrates, FoxJ1 and FoxN4 Forkhead (FKH) TFs work with RFX in the direct activation of ciliome genes, exclusively in motile cilia cell-types. No additional TFs have been described to act together with RFX in primary cilia cell-types in any organism. Here we describe FKH-8, a FKH TF, as a direct regulator of the sensory ciliome genes in Caenorhabditis elegans. FKH-8 is expressed in all ciliated neurons in C. elegans, binds the regulatory regions of ciliome genes, regulates ciliome gene expression, cilium morphology and a wide range of behaviors mediated by sensory ciliated neurons. FKH-8 and DAF-19 (C. elegans RFX) physically interact and synergistically regulate ciliome gene expression. C. elegans FKH-8 function can be replaced by mouse FOXJ1 and FOXN4 but not by other members of other mouse FKH subfamilies. In conclusion, RFX and FKH TF families act jointly as direct regulators of ciliome genes also in sensory ciliated cell types suggesting that this regulatory logic could be an ancient trait predating functional cilia sub-specialization.
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Affiliation(s)
- Rebeca Brocal-Ruiz
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | - Ainara Esteve-Serrano
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | - Carlos Mora-Martínez
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | | | - Peter Swoboda
- Department of Biosciences and Nutrition. Karolinska Institute. Campus FlemingsbergStockholmSweden
| | - Juan J Tena
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas/Universidad Pablo de OlavideSevilleSpain
| | - Marçal Vilar
- Molecular Basis of Neurodegeneration Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | - Nuria Flames
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
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5
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Zhang J, Yang W, Li Z, Huang F, Zhang K. Multigenerational exposure of cadmium trans-generationally impairs locomotive and chemotactic behaviors in Caenorhabditis elegans. CHEMOSPHERE 2023; 325:138432. [PMID: 36933370 DOI: 10.1016/j.chemosphere.2023.138432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/19/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Cadmium is a naturally existing heavy metal and a notorious environmental pollutant. While its toxic outcomes and underlying mechanisms remain largely elusive. To explore the behavioral change caused by multigenerational exposure of cadmium to C. elegans, we challenged the C. elegans with cadmium for six generations and observed its impact on animal behaviors. Wild-type worms were randomly divided into two groups, the control and cadmium exposure groups. Locomotive and chemotactic behaviors were observed across six generations. Head thrashing frequency, chemotaxis index, and fold change index were used to evaluate the neurotoxicity of multigenerational cadmium exposure. Multigenerational cadmium exposure can trans-generationally increase the head thrashing frequency of C. elegans during swimming, and impair the chemotactic behaviors to isoamyl alcohol, diacetyl, and 2-nonanone. Our findings proposed a trans-generationally behavioral impact induced by multigenerational cadmium exposure.
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Affiliation(s)
- Jun Zhang
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Wenxing Yang
- Department of Physiology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Zhuo Li
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Feijun Huang
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Kui Zhang
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China.
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6
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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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7
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Liu H, Wu JJ, Li R, Wang PZ, Huang JH, Xu Y, Zhao JL, Wu PP, Li SJ, Wu ZX. Disexcitation in the ASH/RIM/ADL negative feedback circuit fine-tunes hyperosmotic sensation and avoidance in Caenorhabditis elegans. Front Mol Neurosci 2023; 16:1101628. [PMID: 37008778 PMCID: PMC10050701 DOI: 10.3389/fnmol.2023.1101628] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/21/2023] [Indexed: 03/17/2023] Open
Abstract
Sensations, especially nociception, are tightly controlled and regulated by the central and peripheral nervous systems. Osmotic sensation and related physiological and behavioral reactions are essential for animal well-being and survival. In this study, we find that interaction between secondary nociceptive ADL and primary nociceptive ASH neurons upregulates Caenorhabditis elegans avoidance of the mild and medium hyperosmolality of 0.41 and 0.88 Osm but does not affect avoidance of high osmolality of 1.37 and 2.29 Osm. The interaction between ASH and ADL is actualized through a negative feedback circuit consisting of ASH, ADL, and RIM interneurons. In this circuit, hyperosmolality-sensitive ADL augments the ASH hyperosmotic response and animal hyperosmotic avoidance; RIM inhibits ADL and is excited by ASH; thus, ASH exciting RIM reduces ADL augmenting ASH. The neuronal signal integration modality in the circuit is disexcitation. In addition, ASH promotes hyperosmotic avoidance through ASH/RIC/AIY feedforward circuit. Finally, we find that in addition to ASH and ADL, multiple sensory neurons are involved in hyperosmotic sensation and avoidance behavior.
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8
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Lin A, Qin S, Casademunt H, Wu M, Hung W, Cain G, Tan NZ, Valenzuela R, Lesanpezeshki L, Venkatachalam V, Pehlevan C, Zhen M, Samuel AD. Functional imaging and quantification of multineuronal olfactory responses in C. elegans. SCIENCE ADVANCES 2023; 9:eade1249. [PMID: 36857454 PMCID: PMC9977185 DOI: 10.1126/sciadv.ade1249] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 02/01/2023] [Indexed: 05/21/2023]
Abstract
Many animals perceive odorant molecules by collecting information from ensembles of olfactory neurons, where each neuron uses receptors that are tuned to recognize certain odorant molecules with different binding affinity. Olfactory systems are able, in principle, to detect and discriminate diverse odorants using combinatorial coding strategies. We have combined microfluidics and multineuronal imaging to study the ensemble-level olfactory representations at the sensory periphery of the nematode Caenorhabditis elegans. The collective activity of C. elegans chemosensory neurons reveals high-dimensional representations of olfactory information across a broad space of odorant molecules. We reveal diverse tuning properties and dose-response curves across chemosensory neurons and across odorants. We describe the unique contribution of each sensory neuron to an ensemble-level code for volatile odorants. We show that a natural stimuli, a set of nematode pheromones, are also encoded by the sensory ensemble. The integrated activity of the C. elegans chemosensory neurons contains sufficient information to robustly encode the intensity and identity of diverse chemical stimuli.
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Affiliation(s)
- Albert Lin
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Shanshan Qin
- Center for Brain Science, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Helena Casademunt
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Min Wu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Gregory Cain
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Nicolas Z. Tan
- Department of Physics, Northeastern University, Boston, MA, USA
| | | | - Leila Lesanpezeshki
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | | | - Cengiz Pehlevan
- Center for Brain Science, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Aravinthan D.T. Samuel
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
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9
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Gnatyshyna L, Khoma V, Martinyuk V, Matskiv T, Pedrini-Martha V, Niederwanger M, Stoliar O, Dallinger R. Sublethal cadmium exposure in the freshwater snail Lymnaea stagnalis meets a deficient, poorly responsive metallothionein system while evoking oxidative and cellular stress. Comp Biochem Physiol C Toxicol Pharmacol 2023; 263:109490. [PMID: 36265756 DOI: 10.1016/j.cbpc.2022.109490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/29/2022] [Accepted: 10/12/2022] [Indexed: 11/22/2022]
Abstract
The Great Pond snail Lymnaea stagnalis (Gastropoda, Hygrophila) is a wide-spread freshwater gastropod, being considered as a model organism for research in many fields of biology, including ecotoxicology. The aim of the present study was to explore the Cd sensitivity of L. stagnalis through the measurement of a biomarker battery for oxidative, toxic and cellular stress. The interpretation of biomarker parameters occurred against the background of a truncated metallothionein protein with a limited Cd-binding capacity. Individuals of L. stagnalis were exposed through 14 days to uncontaminated water (controls) or to low (30 μg · L-1) or high (50 μg · L-1) Cd concentrations. The digestive gland of control and low-Cd exposed snails was processed for transcriptional analysis of the Metallothionein (MT) gene expression, and for determination of biomarkers for oxidative stress, toxicity and cellular stress. Digestive gland supernatants of high-Cd exposed snails were subjected to chromatography and subsequent analysis by spectrophotometry. It was shown that the MT system of L. stagnalis is functionally deficient, with a poor Cd responsiveness at both, the transcriptional and the protein expression levels. Instead, L. stagnalis appears to rely on alternative detoxification mechanisms such as Cd binding by phytochelatins and metal inactivation by compartmentalization within the lysosomal system. In spite of this, however, traces of Cd apparently leak out of the pre-determined detoxification pathways, leading to adverse effects, which is clearly indicated by biomarkers of oxidative and cellular stress.
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Affiliation(s)
- Lesya Gnatyshyna
- I.Ya. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine; Ternopil Volodymyr Hnatiuk National Pedagogical University, Ternopil, Ukraine.
| | - Vira Khoma
- Ternopil Volodymyr Hnatiuk National Pedagogical University, Ternopil, Ukraine.
| | - Viktoria Martinyuk
- Ternopil Volodymyr Hnatiuk National Pedagogical University, Ternopil, Ukraine
| | - Tetyana Matskiv
- I.Ya. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine; Ternopil Volodymyr Hnatiuk National Pedagogical University, Ternopil, Ukraine.
| | | | - Michael Niederwanger
- Institute of Zoology, University and Center of Molecular Biosciences, Innsbruck, Austria.
| | - Oksana Stoliar
- Ternopil Volodymyr Hnatiuk National Pedagogical University, Ternopil, Ukraine.
| | - Reinhard Dallinger
- Institute of Zoology, University and Center of Molecular Biosciences, Innsbruck, Austria.
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10
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Positive interaction between ASH and ASK sensory neurons accelerates nociception and inhibits behavioral adaptation. iScience 2022; 25:105287. [PMID: 36304123 PMCID: PMC9593764 DOI: 10.1016/j.isci.2022.105287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/22/2022] [Accepted: 10/04/2022] [Indexed: 11/23/2022] Open
Abstract
Central and peripheral sensory neurons tightly regulate nociception and avoidance behavior. The peripheral modulation of nociception provides more veridical and instantaneous information for animals to achieve rapid, more fine-tuned and concentrated behavioral responses. In this study, we find that positive interaction between ASH and ASK sensory neurons is essential for the fast-rising phase of ASH Ca2+ responses to noxious copper ions and inhibits the adaption of avoiding Cu2+. We reveal the underlying neuronal circuit mechanism. ASK accelerates the ASH Ca2+ responses by transferring cGMP through gap junctions. ASH excites ASK via a disinhibitory neuronal circuit composed of ASH, AIA, and ASK. Avoidance adaptation depends on the slope rate of the rising phase of ASH Ca2+ responses. Thus, in addition to amplitude, sensory kinetics is significant for sensations and behaviors, especially for sensory and behavioral adaptations.
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11
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Miyazaki S, Kawano T, Yanagisawa M, Hayashi Y. Intracellular Ca2+ dynamics in the ALA neuron reflect sleep pressure and regulate sleep in Caenorhabditis elegans. iScience 2022; 25:104452. [PMID: 35707721 PMCID: PMC9189131 DOI: 10.1016/j.isci.2022.104452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/03/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
The mechanisms underlying sleep homeostasis are poorly understood. The nematode Caenorhabditis elegans exhibits 2 types of sleep: lethargus, or developmentally timed, and stress-induced sleep. Lethargus is characterized by alternating cycles of sleep and motion bouts. Sleep bouts are homeostatically regulated, i.e., prolonged active bouts lead to prolonged sleep bouts. Here we reveal that the interneuron ALA is crucial for homeostatic regulation during lethargus. Intracellular Ca2+ in ALA gradually increased during active bouts and rapidly decayed upon transitions to sleep bouts. Longer active bouts were accompanied by higher intracellular Ca2+ peaks. Optogenetic activation of ALA during active bouts caused transitions to sleep bouts. Dysfunction of CEH-17, which is an LIM homeodomain transcription factor selectively expressed in ALA, impaired the characteristic patterns of ALA intracellular Ca2+ and abolished the homeostatic regulation of sleep bouts. These findings indicate that ALA encodes sleep pressure and contributes to sleep homeostasis. ALA gradually increases its activity during motion bouts during lethargus in C. elegans Dysfunction or artificial activation of ALA perturbs the sleep structure ALA plays a crucial role in homeostatic sleep regulation
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Affiliation(s)
- Shinichi Miyazaki
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- PhD Program in Humanics, School of Integrative and Global Majors, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Taizo Kawano
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Life Science Center for Survival Dynamics (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
- R&D Center for Frontiers of Mirai in Policy and Technology (F-MIRAI), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yu Hayashi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 603-8363, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Corresponding author
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12
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Soil Nematodes as the Silent Sufferers of Climate-Induced Toxicity: Analysing the Outcomes of Their Interactions with Climatic Stress Factors on Land Cover and Agricultural Production. Appl Biochem Biotechnol 2022; 195:2519-2586. [PMID: 35593954 DOI: 10.1007/s12010-022-03965-x] [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: 12/23/2021] [Accepted: 05/10/2022] [Indexed: 11/02/2022]
Abstract
Unsustainable anthropogenic activities over the last few decades have resulted in alterations of the global climate. It can be perceived through changes in the rainfall patterns and rise in mean annual temperatures. Climatic stress factors exert their effects on soil health mainly by modifying the soil microenvironments where the soil fauna reside. Among the members of soil fauna, the soil nematodes have been found to be sensitive to these stress factors primarily because of their low tolerance limits. Additionally, because of their higher and diverse trophic positions in the soil food web they can integrate the effects of many stress factors acting together. This is important because under natural conditions the climatic stress factors do not exert their effect individually. Rather, they interact amongst themselves and other abiotic stress factors in the soil to generate their impacts. Some of these interactions may be synergistic while others may be antagonistic. As such, it becomes very difficult to assess their impacts on soil health by simply analysing the physicochemical properties of soil. This makes soil nematodes outstanding candidates for studying the effects of climatic stress factors on soil biology. The knowledge obtained therefrom can be used to design sustainable agricultural practices because most of the conventional techniques aim at short-term benefits with complete disregard of soil biology. This can partly ensure food security in the coming decades for the expanding population. Moreover, understanding soil biology can help to preserve landscapes that have developed over long periods of climatic stability and belowground soil biota interactions.
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McDonagh A, Crew J, van der Linden AM. Dietary vitamin B12 regulates chemosensory receptor gene expression via the MEF2 transcription factor in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2022; 12:6580222. [PMID: 35512190 PMCID: PMC9157118 DOI: 10.1093/g3journal/jkac107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 04/24/2022] [Indexed: 02/02/2023]
Abstract
Dynamic changes in chemoreceptor gene expression levels in sensory neurons are one strategy that an animal can use to modify their responses to dietary changes. However, the mechanisms underlying diet-dependent modulation of chemosensory gene expression are unclear. Here, we show that the expression of the srh-234 chemoreceptor gene localized in a single ADL sensory neuron type of Caenorhabditis elegans is downregulated when animals are fed a Comamonas aquatica bacterial diet, but not on an Escherichia coli diet. Remarkably, this diet-modulated effect on srh-234 expression is dependent on the micronutrient vitamin B12 endogenously produced by Comamonas aq. bacteria. Excess propionate and genetic perturbations in the canonical and shunt propionate breakdown pathways are able to override the repressive effects of vitamin B12 on srh-234 expression. The vitamin B12-mediated regulation of srh-234 expression levels in ADL requires the MEF-2 MADS domain transcription factor, providing a potential mechanism by which dietary vitamin B12 may transcriptionally tune individual chemoreceptor genes in a single sensory neuron type, which in turn may change animal responses to biologically relevant chemicals in their diet.
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Affiliation(s)
- Aja McDonagh
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Jeannette Crew
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Alexander M van der Linden
- Department of Biology, University of Nevada, Reno, NV 89557, USA,Corresponding author: Department of Biology, University of Nevada, Reno, NV 89557, USA.
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14
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Lev I, Zimmer M. Predator–prey interactions: Strategic biting. Curr Biol 2022; 32:R367-R370. [DOI: 10.1016/j.cub.2022.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Wakabayashi T, Nojiri Y, Takahashi-Watanabe M. Multiple Chemosensory Neurons Mediate Avoidance Behavior to Rare Earth Ions in Caenorhabditis elegans. Biol Trace Elem Res 2021; 199:2764-2769. [PMID: 32914378 DOI: 10.1007/s12011-020-02375-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/02/2020] [Indexed: 12/22/2022]
Abstract
As rare earth (RE) metals are abundantly present in the soil, in spite of their name, it is conceivable that organisms may encounter and interact with RE ions. In the present study, we demonstrated that the soil nematode Caenorhabditis elegans avoids RE ions, such as yttrium and all examined lanthanide ions, which exhibit toxic effects on nematodes. We also demonstrated that the chemosensory system of this animal mediates avoidance behavior toward RE ions similar to heavy metal (HM) ion avoidance. The C. elegans dyf-11(pe554) mutant is unable to respond to chemosensory cues because it lacks all ciliated endings of the chemosensory neurons required for the detection of environmental chemicals. Cell-specific rescue of the dyf-11 mutant and cell-specific genetic ablation studies revealed that the avoidance behavior toward HM and RE ions was mediated by a partially overlapping but distinct subset of chemosensory neurons (ASH, ADL, ASE, ADF, and ASK). With the help of multiple chemosensory neurons, worms may improve the fidelity of avoidance behavior to evade RE ions. Among the chemosensory neurons in C. elegans, ADF and ASK neurons were involved in RE avoidance, but not in HM avoidance. These results suggested that ADF and ASK neurons in C. elegans have RE-selective mechanisms to mediate the avoidance response.
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Affiliation(s)
- Tokumitsu Wakabayashi
- Department of Chemistry and Biosciences, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, 020-8551, Japan.
| | - Yui Nojiri
- Department of Chemistry and Biosciences, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, 020-8551, Japan
| | - Miwa Takahashi-Watanabe
- Department of Chemistry and Biosciences, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, 020-8551, Japan
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16
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Berghoff EG, Glenwinkel L, Bhattacharya A, Sun H, Varol E, Mohammadi N, Antone A, Feng Y, Nguyen K, Cook SJ, Wood JF, Masoudi N, Cros CC, Ramadan YH, Ferkey DM, Hall DH, Hobert O. The Prop1-like homeobox gene unc-42 specifies the identity of synaptically connected neurons. eLife 2021; 10:e64903. [PMID: 34165428 PMCID: PMC8225392 DOI: 10.7554/elife.64903] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 05/17/2021] [Indexed: 12/13/2022] Open
Abstract
Many neuronal identity regulators are expressed in distinct populations of cells in the nervous system, but their function is often analyzed only in specific isolated cellular contexts, thereby potentially leaving overarching themes in gene function undiscovered. We show here that the Caenorhabditis elegans Prop1-like homeobox gene unc-42 is expressed in 15 distinct sensory, inter- and motor neuron classes throughout the entire C. elegans nervous system. Strikingly, all 15 neuron classes expressing unc-42 are synaptically interconnected, prompting us to investigate whether unc-42 controls the functional properties of this circuit and perhaps also the assembly of these neurons into functional circuitry. We found that unc-42 defines the routes of communication between these interconnected neurons by controlling the expression of neurotransmitter pathway genes, neurotransmitter receptors, neuropeptides, and neuropeptide receptors. Anatomical analysis of unc-42 mutant animals reveals defects in axon pathfinding and synaptic connectivity, paralleled by expression defects of molecules involved in axon pathfinding, cell-cell recognition, and synaptic connectivity. We conclude that unc-42 establishes functional circuitry by acting as a terminal selector of functionally connected neuron types. We identify a number of additional transcription factors that are also expressed in synaptically connected neurons and propose that terminal selectors may also function as 'circuit organizer transcription factors' to control the assembly of functional circuitry throughout the nervous system. We hypothesize that such organizational properties of transcription factors may be reflective of not only ontogenetic, but perhaps also phylogenetic trajectories of neuronal circuit establishment.
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Affiliation(s)
- Emily G Berghoff
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Lori Glenwinkel
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Abhishek Bhattacharya
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - HaoSheng Sun
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Erdem Varol
- Department of Statistics, Zuckerman Institute, Columbia UniversityNew YorkUnited States
| | - Nicki Mohammadi
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Amelia Antone
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Yi Feng
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Ken Nguyen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Steven J Cook
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Jordan F Wood
- Department of Biological Sciences, University at Buffalo, The State University of New YorkBuffaloUnited States
| | - Neda Masoudi
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Cyril C Cros
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Yasmin H Ramadan
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New YorkBuffaloUnited States
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
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17
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Queirós L, Monteiro L, Marques C, Pereira JL, Gonçalves FJM, Aschner M, Pereira P. Measurement of the Effects of Metals on Taxis-to-Food Behavior in Caenorhabditis elegans. Curr Protoc 2021; 1:e131. [PMID: 33974358 DOI: 10.1002/cpz1.131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Chemosensation in nematodes is linked to processes that affect their ability to survive, such as the search for food and the avoidance of toxic substances. Since the 1970s, numerous studies have assessed chemotaxis in the nematode species Caenorhabditis elegans, focusing on a multitude of agents, including bacteria (food), ions, salts, hormones, volatile organic compounds, and, to a lesser extent, metal-contaminated medium/food. The few studies evaluating metal exposure have reported a variety of responses (neutral, attraction, avoidance), which generally appear to be contaminant and/or concentration specific. Differences in experimental designs, however, hinder appropriate comparison of the findings and attainment of firm conclusions. Therefore, we herein propose and describe a detailed protocol for the assessment of the effects of metals on taxis-to-food behavior in C. elegans. Distinct approaches are proposed in two innovative stages of testing to (1) screen metals' effects on taxis-to-food behavior and (2) classify the behavioral response as attraction/avoidance/indifference or preference. Use of such a standard protocol will allow for easy comparison across studies and direct interpretation of results. Findings using this model system can contribute to a deeper understanding of the real risks of metal contamination to nematodes and how such contaminants could impact ecosystems in general, given the key environmental roles that these organisms play. © 2021 Wiley Periodicals LLC. Basic Protocol: Assessing the effects of metal contamination on taxis-to-food behavior in Caenorhabditis elegans Support Protocol 1: Synchronization of C. elegans by hand-picking gravid worms Support Protocol 2: Synchronization of C. elegans by using a bleaching solution.
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Affiliation(s)
- Libânia Queirós
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Aveiro, Portugal
| | - Luana Monteiro
- Marine Biology Research Group, Biology Department, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Carlos Marques
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Aveiro, Portugal
| | - Joana L Pereira
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Aveiro, Portugal
| | - Fernando J M Gonçalves
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Aveiro, Portugal
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York
| | - Patrícia Pereira
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Aveiro, Portugal
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18
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Queirós L, Marques C, Pereira JL, Gonçalves FJM, Aschner M, Pereira P. Overview of Chemotaxis Behavior Assays in Caenorhabditis elegans. Curr Protoc 2021; 1:e120. [PMID: 33974354 PMCID: PMC8162703 DOI: 10.1002/cpz1.120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Environmental pollution related to anthropogenic pressures, and the associated repercussions on public health, represent a worldwide problem. Thus, the study of the effects that environmental contaminants can pose to natural ecosystems and human health is of vital importance. Laboratory model organisms such as Caenorhabditis elegans have played a significant role in clarifying multilevel effects of those agents. Although the evaluation of contaminant effects at the behavioral level of organisms is an emerging approach in ecotoxicology, studies assessing chemotaxis behavior in C. elegans within the ecotoxicological research context are still scarce. Chemotaxis studies in C. elegans have contributed to the understanding of both the neuronal mechanisms involved in the behavioral effects triggered by environmental cues and the impact of contaminants on natural ecosystems. Its compact and well-characterized nervous system, as well as the availability of transgenic strains and molecular tools, allows a detailed examination of behavioral, molecular, and genetic chemosensation mechanisms. This overview provides a summary and general comparison of methods used to measure chemotaxis behavior in C. elegans, with the aim of helping researchers select the most suitable approach in their chemotaxis studies. We compare methods based on the type of chemical tested, advantages and drawbacks of the different approaches, and specific experimental goals. Lastly, we hope to encourage the evaluation of C. elegans chemotaxis behavior in ecotoxicology studies, as well as its potential integration in standardized protocols assessing environmental quality. © 2021 Wiley Periodicals LLC.
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Affiliation(s)
- Libânia Queirós
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Carlos Marques
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Joana L. Pereira
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Fernando J. M. Gonçalves
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Patrícia Pereira
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193 Aveiro, Portugal
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19
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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: 51] [Impact Index Per Article: 17.0] [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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20
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Signal Decoding for Glutamate Modulating Egg Laying Oppositely in Caenorhabditis elegans under Varied Environmental Conditions. iScience 2020; 23:101588. [PMID: 33089099 PMCID: PMC7567941 DOI: 10.1016/j.isci.2020.101588] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/07/2020] [Accepted: 09/16/2020] [Indexed: 11/24/2022] Open
Abstract
Animals' ability to sense environmental cues and to integrate this information to control fecundity is vital for continuing the species lineage. In this study, we observed that the sensory neurons Amphid neuron (ASHs and ADLs) differentially regulate egg-laying behavior in Caenorhabditis elegans under varied environmental conditions via distinct neuronal circuits. Under standard culture conditions, ASHs tonically release a small amount of glutamate and inhibit Hermaphrodite specific motor neuron (HSN) activities and egg laying via a highly sensitive Glutamate receptor (GLR)-5 receptor. In contrast, under Cu2+ stimulation, ASHs and ADLs may release a large amount of glutamate and inhibit Amphid interneuron (AIA) interneurons via low-sensitivity Glutamate-gated chloride channel (GLC)-3 receptor, thus removing the inhibitory roles of AIAs on HSN activity and egg laying. However, directly measuring the amount of glutamate released by sensory neurons under different conditions and assaying the binding kinetics of receptors with the neurotransmitter are still required to support this study directly. Short-term exposure of CuSO4 evokes hyperactive egg laying ASHs inhibit HSNs and egg laying via GLR-5 receptor under no Cu2+ treatment AIA interneurons suppress HSNs and thus egg laying through ACR-14 signaling Under noxious Cu2+ treatment, ASHs and ADLs suppress AIAs and augment egg laying
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21
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Mehle EA, Sojka SE, K C M, Zel RM, Reese SJ, Ferkey DM. The C. elegans TRPV channel proteins OSM-9 and OCR-2 contribute to aversive chemical sensitivity. MICROPUBLICATION BIOLOGY 2020; 2020. [PMID: 32666046 PMCID: PMC7352062 DOI: 10.17912/micropub.biology.000277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emily A Mehle
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260
| | - Savannah E Sojka
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260
| | - Medha K C
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260
| | - Rosy M Zel
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260
| | - Sebastian J Reese
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260
| | - Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260
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22
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Contiliani DF, de Araújo Ribeiro Y, de Moraes VN, Pereira TC. Panagrolaimus superbus tolerates hypoxia within Gallium metal cage: implications for the understanding of the phenomenon of anhydrobiosis. J Nematol 2020; 52:1-6. [PMID: 32421263 PMCID: PMC7266057 DOI: 10.21307/jofnem-2020-046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Indexed: 11/11/2022] Open
Abstract
Panagrolaimus superbus nematodes are able to tolerate desiccation by entering into a peculiar state of suspended animation known as anhydrobiosis. When desiccated, anhydrobiotic organisms are also able to tolerate other physical stresses, as high and low levels of temperature and pressure. Here, we decided to investigate the tolerance of desiccated P. superbus to an unprecedented double stress - hypoxia within 99.99% Gallium (Ga) metal cage. The authors observed that regardless of the external relative humidity, desiccated P. superbus tolerated 7 d confined within the metal cage, displaying no negative effects on its survival and population growth rates over 40 d. The results evidence that anhydrobiosis also renders nematodes tolerant to otherwise lethal concentrations of Ga, in an oxygen-poor environment; thus, expanding its polyextremotolerance profile. Panagrolaimus superbus nematodes are able to tolerate desiccation by entering into a peculiar state of suspended animation known as anhydrobiosis. When desiccated, anhydrobiotic organisms are also able to tolerate other physical stresses, as high and low levels of temperature and pressure. Here, we decided to investigate the tolerance of desiccated P. superbus to an unprecedented double stress – hypoxia within 99.99% Gallium (Ga) metal cage. The authors observed that regardless of the external relative humidity, desiccated P. superbus tolerated 7 d confined within the metal cage, displaying no negative effects on its survival and population growth rates over 40 d. The results evidence that anhydrobiosis also renders nematodes tolerant to otherwise lethal concentrations of Ga, in an oxygen-poor environment; thus, expanding its polyextremotolerance profile.
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Affiliation(s)
- Danyel Fernandes Contiliani
- Department of Biology , FFCLRP , University of São Paulo , Ribeirão Preto , Brazil ; Graduate Program of Genetics , FMRP , University of São Paulo , Ribeirão Preto , Brazil
| | - Yasmin de Araújo Ribeiro
- Department of Biology , FFCLRP , University of São Paulo , Ribeirão Preto , Brazil ; Graduate Program of Genetics , FMRP , University of São Paulo , Ribeirão Preto , Brazil
| | - Vitor Nolasco de Moraes
- Department of Biology , FFCLRP , University of São Paulo , Ribeirão Preto , Brazil ; Graduate Program of Genetics , FMRP , University of São Paulo , Ribeirão Preto , Brazil
| | - Tiago Campos Pereira
- Department of Biology , FFCLRP , University of São Paulo , Ribeirão Preto , Brazil ; Graduate Program of Genetics , FMRP , University of São Paulo , Ribeirão Preto , Brazil
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23
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Voelker L, Upadhyaya B, Ferkey DM, Woldemariam S, L’Etoile ND, Rabinowitch I, Bai J. INX-18 and INX-19 play distinct roles in electrical synapses that modulate aversive behavior in Caenorhabditis elegans. PLoS Genet 2019; 15:e1008341. [PMID: 31658255 PMCID: PMC6837551 DOI: 10.1371/journal.pgen.1008341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/07/2019] [Accepted: 10/04/2019] [Indexed: 12/23/2022] Open
Abstract
In order to respond to changing environments and fluctuations in internal states, animals adjust their behavior through diverse neuromodulatory mechanisms. In this study we show that electrical synapses between the ASH primary quinine-detecting sensory neurons and the neighboring ASK neurons are required for modulating the aversive response to the bitter tastant quinine in C. elegans. Mutant worms that lack the electrical synapse proteins INX-18 and INX-19 become hypersensitive to dilute quinine. Cell-specific rescue experiments indicate that inx-18 operates in ASK while inx-19 is required in both ASK and ASH for proper quinine sensitivity. Imaging analyses find that INX-19 in ASK and ASH localizes to the same regions in the nerve ring, suggesting that both sides of ASK-ASH electrical synapses contain INX-19. While inx-18 and inx-19 mutant animals have a similar behavioral phenotype, several lines of evidence suggest the proteins encoded by these genes play different roles in modulating the aversive quinine response. First, INX-18 and INX-19 localize to different regions of the nerve ring, indicating that they are not present in the same synapses. Second, removing inx-18 disrupts the distribution of INX-19, while removing inx-19 does not alter INX-18 localization. Finally, by using a fluorescent cGMP reporter, we find that INX-18 and INX-19 have distinct roles in establishing cGMP levels in ASK and ASH. Together, these results demonstrate that electrical synapses containing INX-18 and INX-19 facilitate modulation of ASH nociceptive signaling. Our findings support the idea that a network of electrical synapses mediates cGMP exchange between neurons, enabling modulation of sensory responses and behavior. Animals are constantly adjusting their behavior to respond to changes in the environment or to their internal state. This behavior modulation is achieved by altering the activity of neurons and circuits through a variety of neuroplasticity mechanisms. Chemical synapses are known to impact neuroplasticity in several different ways, but the diversity of mechanisms by which electrical synapses contribute is still being investigated. Electrical synapses are specialized sites of connection between neurons where ions and small signaling molecules can pass directly from one cell to the next. By passing small molecules through electrical synapses, neurons may be able to modify the activity of their neighbors. In this study we identify two genes that contribute to electrical synapses between two sensory neurons in C. elegans. We show that these electrical synapses are crucial for proper modulation of sensory responses, as without them animals are overly responsive to an aversive stimulus. In addition to pinpointing their sites of action, we present evidence that they may be contributing to neuromodulation by facilitating passage of the small molecule cGMP between neurons. Our work provides evidence for a role of electrical synapses in regulating animal behavior.
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Affiliation(s)
- Lisa Voelker
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, United States of America
| | - Bishal Upadhyaya
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Denise M. Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States of America
| | - Sarah Woldemariam
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, United States of America
| | - Noelle D. L’Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, United States of America
| | - Ithai Rabinowitch
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Department of Medical Neurobiology, Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem, Israel
| | - Jihong Bai
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, United States of America
- * E-mail:
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24
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Bryant AS, Hallem EA. Terror in the dirt: Sensory determinants of host seeking in soil-transmitted mammalian-parasitic nematodes. Int J Parasitol Drugs Drug Resist 2018; 8:496-510. [PMID: 30396862 PMCID: PMC6287541 DOI: 10.1016/j.ijpddr.2018.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 12/12/2022]
Abstract
Infection with gastrointestinal parasitic nematodes is a major cause of chronic morbidity and economic burden around the world, particularly in low-resource settings. Some parasitic nematode species, including the human-parasitic threadworm Strongyloides stercoralis and human-parasitic hookworms in the genera Ancylostoma and Necator, feature a soil-dwelling infective larval stage that seeks out hosts for infection using a variety of host-emitted sensory cues. Here, we review our current understanding of the behavioral responses of soil-dwelling infective larvae to host-emitted sensory cues, and the molecular and cellular mechanisms that mediate these responses. We also discuss the development of methods for transgenesis and CRISPR/Cas9-mediated targeted mutagenesis in Strongyloides stercoralis and the closely related rat parasite Strongyloides ratti. These methods have established S. stercoralis and S. ratti as genetic model systems for gastrointestinal parasitic nematodes and are enabling more detailed investigations into the neural mechanisms that underlie the sensory-driven behaviors of this medically and economically important class of parasites.
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Affiliation(s)
- Astra S Bryant
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA.
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25
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Metaxakis A, Petratou D, Tavernarakis N. Multimodal sensory processing in Caenorhabditis elegans. Open Biol 2018; 8:180049. [PMID: 29925633 PMCID: PMC6030117 DOI: 10.1098/rsob.180049] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/22/2018] [Indexed: 12/22/2022] Open
Abstract
Multisensory integration is a mechanism that allows organisms to simultaneously sense and understand external stimuli from different modalities. These distinct signals are transduced into neuronal signals that converge into decision-making neuronal entities. Such decision-making centres receive information through neuromodulators regarding the organism's physiological state and accordingly trigger behavioural responses. Despite the importance of multisensory integration for efficient functioning of the nervous system, and also the implication of dysfunctional multisensory integration in the aetiology of neuropsychiatric disease, little is known about the relative molecular mechanisms. Caenorhabditis elegans is an appropriate model system to study such mechanisms and elucidate the molecular ways through which organisms understand external environments in an accurate and coherent fashion.
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Affiliation(s)
- Athanasios Metaxakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece
| | - Dionysia Petratou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece
- Department of Basic Sciences, Faculty of Medicine, University of Crete, Heraklion 71110, Crete, Greece
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Yuan S, Sharma AK, Richart A, Lee J, Kim BE. CHCA-1 is a copper-regulated CTR1 homolog required for normal development, copper accumulation, and copper-sensing behavior in Caenorhabditis elegans. J Biol Chem 2018; 293:10911-10925. [PMID: 29784876 DOI: 10.1074/jbc.ra118.003503] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Indexed: 01/11/2023] Open
Abstract
Copper plays key roles in catalytic and regulatory biochemical reactions essential for normal growth, development, and health. Dietary copper deficiencies or mutations in copper homeostasis genes can lead to abnormal musculoskeletal development, cognitive disorders, and poor growth. In yeast and mammals, copper is acquired through the activities of the CTR1 family of high-affinity copper transporters. However, the mechanisms of systemic responses to dietary or tissue-specific copper deficiency remain unclear. Here, taking advantage of the animal model Caenorhabditis elegans for studying whole-body copper homeostasis, we investigated the role of a C. elegans CTR1 homolog, CHCA-1, in copper acquisition and in worm growth, development, and behavior. Using sequence homology searches, we identified 10 potential orthologs to mammalian CTR1 Among these genes, we found that chca-1, which is transcriptionally up-regulated in the intestine and hypodermis of C. elegans during copper deficiency, is required for normal growth, reproduction, and maintenance of systemic copper balance under copper deprivation. The intestinal copper transporter CUA-1 normally traffics to endosomes to sequester excess copper, and we found here that loss of chca-1 caused CUA-1 to mislocalize to the basolateral membrane under copper overload conditions. Moreover, animals lacking chca-1 exhibited significantly reduced copper avoidance behavior in response to toxic copper conditions compared with WT worms. These results establish that CHCA-1-mediated copper acquisition in C. elegans is crucial for normal growth, development, and copper-sensing behavior.
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Affiliation(s)
- Sai Yuan
- From the Department of Animal and Avian Sciences and
| | | | | | - Jaekwon Lee
- the Redox Biology Center, Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588
| | - Byung-Eun Kim
- From the Department of Animal and Avian Sciences and .,Biological Sciences Graduate Program, University of Maryland, College Park, Maryland 20742 and
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FLP-18 Functions through the G-Protein-Coupled Receptors NPR-1 and NPR-4 to Modulate Reversal Length in Caenorhabditis elegans. J Neurosci 2018; 38:4641-4654. [PMID: 29712787 PMCID: PMC5965667 DOI: 10.1523/jneurosci.1955-17.2018] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 03/27/2018] [Accepted: 03/31/2018] [Indexed: 01/03/2023] Open
Abstract
Animal behavior is critically dependent on the activity of neuropeptides. Reversals, one of the most conspicuous behaviors in Caenorhabditis elegans, plays an important role in determining the navigation strategy of the animal. Our experiments on hermaphrodite C. elegans show the involvement of a neuropeptide FLP-18 in modulating reversal length in these hermaphrodites. We show that FLP-18 controls the reversal length by regulating the activity of AVA interneurons through the G-protein-coupled neuropeptide receptors, NPR-4 and NPR-1. We go on to show that the site of action of these receptors is the AVA interneuron for NPR-4 and the ASE sensory neurons for NPR-1. We further show that mutants in the neuropeptide, flp-18, and its receptors show increased reversal lengths. Consistent with the behavioral data, calcium levels in the AVA neuron of freely reversing C. elegans were significantly higher and persisted for longer durations in flp-18, npr-1, npr-4, and npr-1 npr-4 genetic backgrounds compared with wild-type control animals. Finally, we show that increasing FLP-18 levels through genetic and physiological manipulations causes shorter reversal lengths. Together, our analysis suggests that the FLP-18/NPR-1/NPR-4 signaling is a pivotal point in the regulation of reversal length under varied genetic and environmental conditions. SIGNIFICANCE STATEMENT In this study, we elucidate the circuit and molecular machinery required for normal reversal behavior in hermaphrodite Caenorhabditis elegans. We delineate the circuit and the neuropeptide receptors required for maintaining reversal length in C. elegans. Our work sheds light on the importance of a single neuropeptide, FLP-18, and how change in levels in this one peptide could allow the animal to change the length of its reversal, thereby modulating how the C. elegans explores its environment. We also go on to show that FLP-18 functions to maintain reversal length through the neuropeptide receptors NPR-4 and NPR-1. Our study will allow for a better understanding of the complete repertoire of behaviors shown by freely moving animals as they explore their environment.
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Castro BB, Silva C, Macário IPE, Oliveira B, Gonçalves F, Pereira JL. Feeding inhibition in Corbicula fluminea (O.F. Muller, 1774) as an effect criterion to pollutant exposure: Perspectives for ecotoxicity screening and refinement of chemical control. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 196:25-34. [PMID: 29328973 DOI: 10.1016/j.aquatox.2018.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 12/13/2017] [Accepted: 01/03/2018] [Indexed: 05/20/2023]
Abstract
Bivalves are commonly used in biomonitoring programs to track pollutants. Several features, including its filter-feeding abilities, cumulatively argue in favour of the use of the Asian clam (Corbicula fluminea) as a biosentinel and an ecotoxicological model. Filtration in bivalves is very sensitive to external stimuli and its control is dictated by regulation of the opening/closure of the valves, which may be used as an avoidance defence against contaminants. Here, we investigate the filter-feeding behaviour of the Asian clam as an endpoint for assessing exposure to pollutants, driven by two complementary goals: (i) to generate relevant and sensitive toxicological information based on the ability of C. fluminea to clear an algal suspension, using the invasive species as a surrogate for native bivalves; (ii) to gain insight on the potential of exploring this integrative response in the refinement of chemical control methods for this pest. Clearance rates and proportion of algae removed were measured using a simple and reproducible protocol. Despite some variation across individuals and size classes, 50-90% of food particles were generally removed within 60-120 min by clams larger than 20 mm. Removal of algae was sensitive to an array of model contaminants with biocide potential, including fertilizers, pesticides, metals and salts: eight out of nine tested substances were detected at the μg l-1 or mg l-1 range and triggered valve closure, decreasing filter-feeding in a concentration-dependent manner. For most toxicants, a good agreement between mortality (96 h - LC50 within the range 0.4-5500 mg l-1) and feeding (2 h - IC50 within the range 0.005-2317 mg l-1) was observed, demonstrating that a 120-min assay can be used as a protective surrogate of acute toxicity. However, copper sulphate was very strongly avoided by the clams (IC50 = 5.3 μg l-1); on the contrary, dichlorvos (an organophosphate insecticide) did not cause feeding depression, either by being undetected by the clams' chemosensors and/or by interfering with the valve closure mechanism. Such an assay has a large potential as a simple screening tool for industry, environmental agencies and managers. The ability of dichlorvos to bypass the Asian clam's avoidance strategy puts it in the spotlight as a potential agent to be used alone or combined with others in eradication programs of this biofouler in closed or semi-closed industrial settings.
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Affiliation(s)
- Bruno Branco Castro
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal
| | - Carlos Silva
- Department of Biology, University of Aveiro, Portugal
| | - Inês Patrunilho Efe Macário
- Department of Biology, University of Aveiro, Portugal; CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal
| | | | - Fernando Gonçalves
- Department of Biology, University of Aveiro, Portugal; CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal
| | - Joana Luísa Pereira
- Department of Biology, University of Aveiro, Portugal; CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal.
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Buntschuh I, Raps DA, Joseph I, Reid C, Chait A, Totanes R, Sawh M, Li C. FLP-1 neuropeptides modulate sensory and motor circuits in the nematode Caenorhabditis elegans. PLoS One 2018; 13:e0189320. [PMID: 29293515 PMCID: PMC5749679 DOI: 10.1371/journal.pone.0189320] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/23/2017] [Indexed: 11/19/2022] Open
Abstract
Parasitic nematodes infect over one quarter of the population worldwide, causing morbidity in over one billion people. Current anthelmintic drugs are beginning to lose effectiveness due to the presence of resistant strains. We are interested in the role of neuropeptides, which regulate behaviors in all organisms, as another possible target for anthelmintic drugs. FMRFamide-related peptides (FaRPs) are a family of neuropeptides that are conserved throughout the animal kingdom. In particular, nematodes contain the largest family of FaRPs identified thus far and many of these FaRPs are identical among different nematode species; FaRPs in nematodes are collectively referred to as FLPs (FMRFamide-like peptides). However, little is known about the function of these FLPs. We are using the non-parasitic nematode Caenorhabditis elegans as a model for examining FLPs in nematodes. C. elegans contains at least 31 flp genes that encode 72 potential FLPs. Among the flp genes, flp-1 is one of the few that is universally found in nematodes. FLP-1 neuropeptides were previously reported to be involved in sensory and motor functions. However, previous alleles of flp-1 also disrupted a neighboring gene, daf-10. To understand the phenotypes of flp-1, new alleles that specifically disrupt flp-1 were characterized. The previously reported locomotory and egg-laying defects were found to be due to loss of flp-1, while the osmolarity defect is due to loss of daf-10. In addition, loss of flp-1 and daf-10 both cause several phenotypes that increase in severity in the double mutants by disrupting different neurons in the neural circuits.
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Affiliation(s)
- Ingrid Buntschuh
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Daniel A. Raps
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Ivor Joseph
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Christopher Reid
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Alexander Chait
- Department of Psychology, City College of New York, City University of New York, New York, NY, United States of America
| | - Raubern Totanes
- Department of Physics, City College of New York, City University of New York, New York, NY, United States of America
| | - Michelle Sawh
- Department of Chemistry & Biochemistry, City College of New York, City University of New York, New York, NY, United States of America
| | - Chris Li
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
- The Graduate Center, City University of New York, New York, NY, United States of America
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30
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Campbell JC, Chin-Sang ID, Bendena WG. A Caenorhabditis elegans Nutritional-status Based Copper Aversion Assay. J Vis Exp 2017:55939. [PMID: 28784963 PMCID: PMC5612601 DOI: 10.3791/55939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
To ensure survival, organisms must be capable of avoiding unfavorable habitats while ensuring a consistent food source. Caenorhabditis elegans alter their locomotory patterns upon detection of diverse environmental stimuli and can modulate their suite of behavioral responses in response to starvation conditions. Nematodes typically exhibit a decreased aversive response when removed from a food source for over 30 min. Observation of behavioral changes in response to a changing nutritional status can provide insight into the mechanisms that regulate the transition from a well-fed to starved state. We have developed an assay that measures a nematode's ability to cross an aversive barrier (i.e. copper) then reach a food source over a prolonged period of time. This protocol builds upon previous work by integrating multiple variables in a manner that allows for continued data collection as the organisms shift towards an increasingly starved condition. Moreover, this assay permits an increased sample size so that larger populations of nematodes can be simultaneously evaluated. Organisms defective for the ability to detect or respond to copper immediately cross the chemical barrier, while wild type nematodes are initially repelled. As wild type worms are increasingly starved, they begin to cross the barrier and reach the food source. We designed this assay to evaluate a mutant that is incapable of responding to diverse environmental cues, including food sensation or detection of aversive chemicals. When evaluated via this protocol, the defective organisms immediately crossed the barrier, but were also incapable of detecting a food source. Hence, these mutants repeatedly cross the chemical barrier despite temporarily reaching a food source. This assay can straightforwardly test populations of worms to evaluate potential pathway defects related to aversion and starvation.
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Affiliation(s)
| | | | - William G Bendena
- Department of Biology, Queen's University; Centre for Neuroscience, Queen's University
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31
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Hussey R, Stieglitz J, Mesgarzadeh J, Locke TT, Zhang YK, Schroeder FC, Srinivasan S. Pheromone-sensing neurons regulate peripheral lipid metabolism in Caenorhabditis elegans. PLoS Genet 2017; 13:e1006806. [PMID: 28545126 PMCID: PMC5456406 DOI: 10.1371/journal.pgen.1006806] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 06/02/2017] [Accepted: 05/05/2017] [Indexed: 12/03/2022] Open
Abstract
It is now established that the central nervous system plays an important role in regulating whole body metabolism and energy balance. However, the extent to which sensory systems relay environmental information to modulate metabolic events in peripheral tissues has remained poorly understood. In addition, it has been challenging to map the molecular mechanisms underlying discrete sensory modalities with respect to their role in lipid metabolism. In previous work our lab has identified instructive roles for serotonin signaling as a surrogate for food availability, as well as oxygen sensing, in the control of whole body metabolism. In this study, we now identify a role for a pair of pheromone-sensing neurons in regulating fat metabolism in C. elegans, which has emerged as a tractable and highly informative model to study the neurobiology of metabolism. A genetic screen revealed that GPA-3, a member of the Gα family of G proteins, regulates body fat content in the intestine, the major metabolic organ for C. elegans. Genetic and reconstitution studies revealed that the potent body fat phenotype of gpa-3 null mutants is controlled from a pair of neurons called ADL(L/R). We show that cAMP functions as the second messenger in the ADL neurons, and regulates body fat stores via the neurotransmitter acetylcholine, from downstream neurons. We find that the pheromone ascr#3, which is detected by the ADL neurons, regulates body fat stores in a GPA-3-dependent manner. We define here a third sensory modality, pheromone sensing, as a major regulator of body fat metabolism. The pheromone ascr#3 is an indicator of population density, thus we hypothesize that pheromone sensing provides a salient 'denominator' to evaluate the amount of food available within a population and to accordingly adjust metabolic rate and body fat levels. The central nervous system plays a vital role in regulating whole body metabolism and energy balance. However, the precise cellular, genetic and molecular mechanisms underlying these effects remain a major unsolved mystery. C. elegans has emerged as a tractable and highly informative model to study the neurobiology of metabolism. Previously, we have identified instructive roles for serotonin signaling as a surrogate for food availability, as well as oxygen sensing, in the control of whole body metabolism. In our current study we have identified a role for a pair of pheromone-sensing neurons in regulating fat metabolism in C. elegans. cAMP acts as a second messenger in these neurons, and regulates body fat stores via acetylcholine signaling in the nervous system. We find that the population-density-sensing pheromone detected by these neurons regulates body fat stores. Together, we define a third sensory modality, population density sensing, as a major regulator of body fat metabolism.
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Affiliation(s)
- Rosalind Hussey
- Department of Molecular Medicine and Department of Neuroscience, The Scripps Research Institute, La Jolla, California, United States of America
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jon Stieglitz
- Kellogg School of Science and Technology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jaleh Mesgarzadeh
- Department of Molecular Medicine and Department of Neuroscience, The Scripps Research Institute, La Jolla, California, United States of America
- Department of Biology, University of California, San Diego, La Jolla, California, United States of America
| | - Tiffany T. Locke
- Department of Biology, University of California, San Diego, La Jolla, California, United States of America
| | - Ying K. Zhang
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Frank C. Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Supriya Srinivasan
- Department of Molecular Medicine and Department of Neuroscience, The Scripps Research Institute, La Jolla, California, United States of America
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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Soares FA, Fagundez DA, Avila DS. Neurodegeneration Induced by Metals in Caenorhabditis elegans. ADVANCES IN NEUROBIOLOGY 2017; 18:355-383. [PMID: 28889277 DOI: 10.1007/978-3-319-60189-2_18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Metals are a component of a variety of ecosystems and organisms. They can generally be divided into essential and nonessential metals. The essential metals are involved in physiological processes once the deficiency of these metals has been associated with diseases. Although iron, manganese, copper, and zinc are important for life, it has been evidenced that they are also involved in neuronal damage in many neurodegenerative disorders. Nonessential metals, which are metals without physiological functions, are present in trace or higher levels in living organisms. Occupational, environmental, or deliberate exposures to lead, mercury, aluminum, and cadmium are clearly correlated with the increase of toxicity and varied kinds of pathological situations. Actually, the field of neurotoxicology needs to satisfy two opposing demands: the testing of a growing list of chemicals and resource limitations and ethical concerns associated with testing using traditional mammalian species. Toxicological assays using alternative animal models may relieve some of this pressure by allowing testing of more compounds while reducing expenses and using fewer mammals. The nervous system is by far the more complex system in C. elegans. Almost a third of their cells are neurons (302 neurons versus 959 cells in adult hermaphrodite). It initially underwent extensive development as a model organism in order to study the nervous system, and its neuronal lineage and the complete wiring diagram of its nervous system are stereotyped and fully described. The neurotransmission systems are phylogenetically conserved from nematodes to vertebrates, which allows for findings from C. elegans to be extrapolated and further confirmed in vertebrate systems. Different strains of C. elegans offer a new perspective on neurodegenerative processes. Some genes have been found to be related to neurodegeneration induced by metals. Studying these interactions may be an effective tool to slow neuronal loss and deterioration.
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Affiliation(s)
- Felix Antunes Soares
- Departamento de Bioquimica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, 97105-900, Brazil.
| | | | - Daiana Silva Avila
- Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, 97508-000, Brazil.
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Li CW, Lo CC, Chen BS. Estimating Sensorimotor Mapping From Stimuli to Behaviors to Infer C. elegans Movements by Neural Transmission Ability Through Connectome Databases. IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 2016; 27:2229-2241. [PMID: 26415185 DOI: 10.1109/tnnls.2015.2475395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
One of the ultimate goals of computational neuroscience is to quantitatively connect between complex neural circuits and behaviors. In the past decades, the touch response circuit in Caenorhabditis elegans (C. elegans) has extensively been investigated in studies using genetically modified or laser-ablated worms. Synaptic connections, including chemical and electrical synapses, have been identified for most neurons in the C. elegans. However, we still do not know whether the empirically observed touch responses can be derived from connectome reconstructed from databases. To address this issue, we defined the transmission abilities (or levels) of neurons in a rate model in order to infer the behaviors of wild-type and ablated worms in response to posterior/nose/anterior touch stimuli. Our analysis showed that transmission abilities can be used to identify sensorimotor mapping from stimuli to movements and then to infer the C. elegans behaviors under simulations based on the perspective of decision-making, and provide useful information about how chemical and electronic synapses should be combined in the neural network movement analysis. This paper reveals an efficient tool that provided insights into the functions of complex neural circuits.
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Demuynck S, Lebel A, Grumiaux F, Pernin C, Leprêtre A, Lemière S. Comparative avoidance behaviour of the earthworm Eisenia fetida towards chloride, nitrate and sulphate salts of Cd, Cu and Zn using filter paper and extruded water agar gels as exposure media. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2016; 129:66-74. [PMID: 26995062 DOI: 10.1016/j.ecoenv.2016.03.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 03/03/2016] [Accepted: 03/08/2016] [Indexed: 06/05/2023]
Abstract
We studied the avoidance behaviour of the earthworm Eisenia fetida towards Cd, Cu, and Zn, trace elements (TEs) tested as chloride, nitrate and sulphate salts. Sub adults were exposed individually using dual-cell chambers at 20+2°C in the dark. Recordings were realised at different dates from 2h to 32h. We used filter paper and extruded water agar gel as exposure media to evaluate the contribution of the dermal and the digestive exposure routes on the avoidance reactions. Exposures to Cu or Cd (10mgmetal ionL(-1)) resulted in highly significant avoidance reactions through the exposure duration. Worms avoided Zn poorly and reactions towards Zn salts varied along the exposure. Worm sensitivity towards TEs differed between salts and this could result from differential toxicity or accessibility of these TE salts to earthworms. The anion in itself was not the determinant of the avoidance reactions since exposures to similar concentrations of these anions using calcium salts did not result in significant avoidance worm behaviour. Avoidance responses towards TEs were higher in the case of water agar exposures than in filter paper exposures. Thus, dermal contacts with TE solutions would elicit worm avoidance but signals from receptors located inside the digestive tract could reinforce this behaviour. The use of extruded water agar gels as the substrate allows checking the real sensitivity of earthworm species towards TEs since the TE concentrations leading to significant avoidance reactions were below those reported in the literature when using TE-spiked soils.
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Affiliation(s)
- Sylvain Demuynck
- Université Lille Nord de France, Lille, France; Laboratoire Génie Civil et géo-Environnement (LGCgE) Université de Lille, Univ. Lille 1, Équipe Fonctionnement des Ecosystèmes Terrestres Anthropisés, Bâtiment SN3, Cité Scientifique, F-59655 Villeneuve d'Ascq, Cedex, France
| | | | - Fabien Grumiaux
- Université Lille Nord de France, Lille, France; Laboratoire Génie Civil et géo-Environnement (LGCgE) Université de Lille, Univ. Lille 1, Équipe Fonctionnement des Ecosystèmes Terrestres Anthropisés, Bâtiment SN3, Cité Scientifique, F-59655 Villeneuve d'Ascq, Cedex, France; Ecole Supérieure du Professorat et de l'Education (ESPE), Site d'Arras, 7 bis rue Raoul François, BP 30927, F-62022 Arras Cedex, France
| | - Céline Pernin
- Université Lille Nord de France, Lille, France; Laboratoire Génie Civil et géo-Environnement (LGCgE) Université de Lille, Univ. Lille 1, Équipe Fonctionnement des Ecosystèmes Terrestres Anthropisés, Bâtiment SN3, Cité Scientifique, F-59655 Villeneuve d'Ascq, Cedex, France
| | - Alain Leprêtre
- Université Lille Nord de France, Lille, France; Laboratoire Génie Civil et géo-Environnement (LGCgE) Université de Lille, Univ. Lille 1, Équipe Fonctionnement des Ecosystèmes Terrestres Anthropisés, Bâtiment SN3, Cité Scientifique, F-59655 Villeneuve d'Ascq, Cedex, France
| | - Sébastien Lemière
- Université Lille Nord de France, Lille, France; Laboratoire Génie Civil et géo-Environnement (LGCgE) Université de Lille, Univ. Lille 1, Équipe Fonctionnement des Ecosystèmes Terrestres Anthropisés, Bâtiment SN3, Cité Scientifique, F-59655 Villeneuve d'Ascq, Cedex, France
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Krzyzanowski MC, Woldemariam S, Wood JF, Chaubey AH, Brueggemann C, Bowitch A, Bethke M, L’Etoile ND, Ferkey DM. Aversive Behavior in the Nematode C. elegans Is Modulated by cGMP and a Neuronal Gap Junction Network. PLoS Genet 2016; 12:e1006153. [PMID: 27459302 PMCID: PMC4961389 DOI: 10.1371/journal.pgen.1006153] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 06/08/2016] [Indexed: 01/03/2023] Open
Abstract
All animals rely on their ability to sense and respond to their environment to survive. However, the suitability of a behavioral response is context-dependent, and must reflect both an animal's life history and its present internal state. Based on the integration of these variables, an animal's needs can be prioritized to optimize survival strategies. Nociceptive sensory systems detect harmful stimuli and allow for the initiation of protective behavioral responses. The polymodal ASH sensory neurons are the primary nociceptors in C. elegans. We show here that the guanylyl cyclase ODR-1 functions non-cell-autonomously to downregulate ASH-mediated aversive behaviors and that ectopic cGMP generation in ASH is sufficient to dampen ASH sensitivity. We define a gap junction neural network that regulates nociception and propose that decentralized regulation of ASH signaling can allow for rapid correlation between an animal's internal state and its behavioral output, lending modulatory flexibility to this hard-wired nociceptive neural circuit.
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Affiliation(s)
- Michelle C. Krzyzanowski
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Sarah Woldemariam
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
| | - Jordan F. Wood
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Aditi H. Chaubey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Chantal Brueggemann
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
| | - Alexander Bowitch
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Mary Bethke
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
| | - Noelle D. L’Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
| | - Denise M. Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
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Dietrich N, Tan CH, Cubillas C, Earley BJ, Kornfeld K. Insights into zinc and cadmium biology in the nematode Caenorhabditis elegans. Arch Biochem Biophys 2016; 611:120-133. [PMID: 27261336 DOI: 10.1016/j.abb.2016.05.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/18/2016] [Accepted: 05/28/2016] [Indexed: 10/21/2022]
Abstract
Zinc is an essential metal that is involved in a wide range of biological processes, and aberrant zinc homeostasis is implicated in multiple human diseases. Cadmium is chemically similar to zinc, but it is a nonessential environmental pollutant. Because zinc deficiency and excess are deleterious, animals require homeostatic mechanisms to maintain zinc levels in response to dietary fluctuations. The nematode Caenorhabditis elegans is emerging as a powerful model system to investigate zinc trafficking and homeostasis as well as cadmium toxicity. Here we review genetic and molecular studies that have combined to generate a picture of zinc homeostasis based on the transcriptional control of zinc transporters in intestinal cells. Furthermore, we summarize studies of cadmium toxicity that reveal intriguing parallels with zinc biology.
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Affiliation(s)
- Nicholas Dietrich
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States.
| | - Chieh-Hsiang Tan
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Ciro Cubillas
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Brian James Earley
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
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Neal SJ, Park J, DiTirro D, Yoon J, Shibuya M, Choi W, Schroeder FC, Butcher RA, Kim K, Sengupta P. A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2016; 6:1475-87. [PMID: 26976437 PMCID: PMC4856098 DOI: 10.1534/g3.115.026450] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/07/2016] [Indexed: 01/09/2023]
Abstract
Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer) mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation.
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Affiliation(s)
- Scott J Neal
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - JiSoo Park
- Department of Brain and Cognitive Sciences, DGIST, Daegu 711-873, Republic of Korea
| | - Danielle DiTirro
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - Jason Yoon
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - Mayumi Shibuya
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - Woochan Choi
- Department of Brain and Cognitive Sciences, DGIST, Daegu 711-873, Republic of Korea
| | - Frank C Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, New York 14853 Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611
| | - Kyuhyung Kim
- Department of Brain and Cognitive Sciences, DGIST, Daegu 711-873, Republic of Korea
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
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cGMP Signalling Mediates Water Sensation (Hydrosensation) and Hydrotaxis in Caenorhabditis elegans. Sci Rep 2016; 6:19779. [PMID: 26891989 PMCID: PMC4759535 DOI: 10.1038/srep19779] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 12/07/2015] [Indexed: 12/24/2022] Open
Abstract
Animals have developed the ability to sense the water content in their habitats, including hygrosensation (sensing humidity in the air) and hydrosensation (sensing the water content in other microenvironments), and they display preferences for specific water contents that influence their mating, reproduction and geographic distribution. We developed and employed four quantitative behavioural test paradigms to investigate the molecular and cellular mechanisms underlying sensing the water content in an agar substrate (hydrosensation) and hydrotaxis in Caenorhabditis elegans. By combining a reverse genetic screen with genetic manipulation, optogenetic neuronal manipulation and in vivo Ca2+ imaging, we demonstrate that adult worms avoid the wetter areas of agar plates and hypo-osmotic water droplets. We found that the cGMP signalling pathway in ciliated sensory neurons is involved in hydrosensation and hydrotaxis in Caenorhabditis elegans.
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Prasanth MI, Santoshram GS, Bhaskar JP, Balamurugan K. Ultraviolet-A triggers photoaging in model nematode Caenorhabditis elegans in a DAF-16 dependent pathway. AGE (DORDRECHT, NETHERLANDS) 2016; 38:27. [PMID: 26873884 PMCID: PMC5005890 DOI: 10.1007/s11357-016-9889-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 02/03/2016] [Indexed: 05/06/2023]
Abstract
Ultraviolet radiations (UV) are the primary causative agent for skin aging (photoaging) and cancer, especially UV-A. The mode of action and the molecular mechanism behind the damages caused by UV-A is not well studied, in vivo. The current study was employed to investigate the impact of UV-A exposure using the model organism, Caenorhabditis elegans. Analysis of lifespan, healthspan, and other cognitive behaviors were done which was supported by the molecular mechanism. UV-A exposure on collagen damages the synthesis and functioning which has been monitored kinetically using engineered strain, col-19:: GFP. The study results suggested that UV-A accelerated the aging process in an insulin-like signaling pathway dependent manner. Mutant (daf-2)-based analysis concrete the observations of the current study. The UV-A exposure affected the usual behavior of the worms like pharyngeal movements and brood size. Quantitative PCR profile of the candidate genes during UV-A exposure suggested that continuous exposure has damaged the neural network of the worms, but the mitochondrial signaling and dietary restriction pathway remain unaffected. Western blot analysis of HSF-1 evidenced the alteration in protein homeostasis in UV-A exposed worms. Outcome of the current study supports our view that C. elegans can be used as a model to study photoaging, and the mode of action of UV-A-mediated damages can be elucidated which will pave the way for drug developments against photoaging.
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Affiliation(s)
- Mani Iyer Prasanth
- Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, Tamil Nadu, -630 004, India
| | | | - James Prabhanand Bhaskar
- ITC - Life Sciences and Technology Centre, ITC Limited, No. 3, 1st Main, Peenya Industrial Area, Bangalore, Karnataka, 560058, India
| | - Krishnaswamy Balamurugan
- Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, Tamil Nadu, -630 004, India.
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Wakabayashi T, Sakata K, Togashi T, Itoi H, Shinohe S, Watanabe M, Shingai R. Navigational choice between reversal and curve during acidic pH avoidance behavior in Caenorhabditis elegans. BMC Neurosci 2015; 16:79. [PMID: 26584677 PMCID: PMC4653917 DOI: 10.1186/s12868-015-0220-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/05/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Under experimental conditions, virtually all behaviors of Caenorhabditis elegans are achieved by combinations of simple locomotion, including forward, reversal movement, turning by deep body bending, and gradual shallow turning. To study how worms regulate these locomotion in response to sensory information, acidic pH avoidance behavior was analyzed by using worm tracking system. RESULTS In the acidic pH avoidance, we characterized two types of behavioral maneuvers that have similar behavioral sequences in chemotaxis and thermotaxis. A stereotypic reversal-turn-forward sequence of reversal avoidance caused an abrupt random reorientation, and a shallow gradual turn in curve avoidance caused non-random reorientation in a less acidic direction to avoid the acidic pH. Our results suggest that these two maneuvers were each triggered by a distinct threshold pH. A simulation study using the two-distinct-threshold model reproduced the avoidance behavior of the real worm, supporting the presence of the threshold. Threshold pH for both reversal and curve avoidance was altered in mutants with reduced or enhanced glutamatergic signaling from acid-sensing neurons. CONCLUSIONS C. elegans employ two behavioral maneuvers, reversal (klinokinesis) and curve (klinotaxis) to avoid acidic pH. Unlike the chemotaxis in C. elegans, reversal and curve avoidances were triggered by absolute pH rather than temporal derivative of stimulus concentration in this behavior. The pH threshold is different between reversal and curve avoidance. Mutant studies suggested that the difference results from a differential amount of glutamate released from ASH and ASK chemosensory neurons.
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Affiliation(s)
- Tokumitsu Wakabayashi
- Department of Chemistry and Biological Sciences, Faculty of Engineering, Iwate University, Iwate, 020-8551, Japan.
| | - Kazumi Sakata
- Department of Chemistry and Biological Sciences, Faculty of Engineering, Iwate University, Iwate, 020-8551, Japan.
| | - Takuya Togashi
- Department of Chemistry and Biological Sciences, Faculty of Engineering, Iwate University, Iwate, 020-8551, Japan.
| | - Hiroaki Itoi
- Department of Chemistry and Biological Sciences, Faculty of Engineering, Iwate University, Iwate, 020-8551, Japan.
| | - Sayaka Shinohe
- Department of Chemistry and Biological Sciences, Faculty of Engineering, Iwate University, Iwate, 020-8551, Japan.
| | - Miwa Watanabe
- Department of Chemistry and Biological Sciences, Faculty of Engineering, Iwate University, Iwate, 020-8551, Japan.
| | - Ryuzo Shingai
- Department of Chemistry and Biological Sciences, Faculty of Engineering, Iwate University, Iwate, 020-8551, Japan.
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41
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Wang W, Xu ZJ, Wu YQ, Qin LW, Li ZY, Wu ZX. Off-response in ASH neurons evoked by CuSO4 requires the TRP channel OSM-9 in Caenorhabditis elegans. Biochem Biophys Res Commun 2015; 461:463-8. [PMID: 25871795 DOI: 10.1016/j.bbrc.2015.04.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 04/03/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Wei Wang
- Key Laboratory of Molecular Biophysics, Ministry of Education, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, PR China
| | - Zi-Jing Xu
- Key Laboratory of Molecular Biophysics, Ministry of Education, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, PR China
| | - Ya-Qian Wu
- Key Laboratory of Molecular Biophysics, Ministry of Education, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, PR China
| | - Li-Wei Qin
- Key Laboratory of Molecular Biophysics, Ministry of Education, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, PR China
| | - Zhao-Yu Li
- Key Laboratory of Molecular Biophysics, Ministry of Education, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, PR China
| | - Zheng-Xing Wu
- Key Laboratory of Molecular Biophysics, Ministry of Education, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, PR China.
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42
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Campbell JC, Chin-Sang ID, Bendena WG. Mechanosensation circuitry in Caenorhabditis elegans: A focus on gentle touch. Peptides 2015; 68:164-74. [PMID: 25543196 DOI: 10.1016/j.peptides.2014.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/14/2014] [Accepted: 12/15/2014] [Indexed: 01/02/2023]
Abstract
Forward or reverse movement in Caenorhabditis elegans is the result of sequential contraction of muscle cells arranged along the body. In larvae, muscle cells are innervated by distinct classes of motorneurons. B motorneurons regulate forward movement and A motorneurons regulate backward movement. Ablation of the D motor neurons results in animals that are uncoordinated in either direction, which suggests that D motorneurons regulate the interaction between the two circuits. C. elegans locomotion is dictated by inputs from interneurons that regulate the activity of motorneurons which coordinate muscle contraction to facilitate forward or backwards movement. As C. elegans moves through the environment, sensory neurons interpret chemical and mechanical information which is relayed to the motor neurons that control locomotory direction. A mechanosensory input known as light nose touch can be simulated in the laboratory by touching the nose of the animal with a human eyebrow hair. The recoil reaction that follows from light nose touch appears to be primarily mediated by glutamate release from the polymodal sensory neuron ASH. Numerous glutamate receptor types are found in different neurons and interneurons which suggest that several pathways may regulate the aversive response. Based on the phenotypes of mutants in which neuropeptide processing is abolished, neuropeptides play a role in circuit regulation. The light touch response is also regulated by transient receptor channel proteins and degenerin/epithelial sodium channels which modulate the activity of sensory neurons involved in the nose touch response.
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Affiliation(s)
- Jason C Campbell
- Department of Biology, Biosciences Complex, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Ian D Chin-Sang
- Department of Biology, Biosciences Complex, Queen's University, Kingston, ON K7L 3N6, Canada
| | - William G Bendena
- Department of Biology, Biosciences Complex, Queen's University, Kingston, ON K7L 3N6, Canada; Centre for Neuroscience, Queen's University, Kingston, ON K7L 3N6, Canada.
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Gruner M, van der Linden AM. Plasticity of chemoreceptor gene expression: Sensory and circuit inputs modulate state-dependent chemoreceptors. WORM 2015; 4:e1023497. [PMID: 26430563 PMCID: PMC4588537 DOI: 10.1080/21624054.2015.1023497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 02/20/2015] [Indexed: 10/25/2022]
Abstract
Animals dramatically modify their chemosensory behaviors when starved, which could allow them to alter and optimize their food-search strategies. Dynamic changes in the gene expression of chemoreceptors may be a general mechanism underlying food and state-dependent changes in chemosensory behaviors. In our recent study,(1) we identified chemoreceptors in the ADL sensory neuron type of C. elegans that are modulated by feeding state and food availability. Here, we highllight our recent findings by which sensory inputs into ADL, neuronal outputs from ADL, and circuit inputs from the RMG interneuron, which is electrically connected to ADL, are required to regulate an ADL-expressed chemoreceptor. This sensory and circuit-mediated regulation of chemoreceptor gene expression is dependent on cell-autonomous pathways acting in ADL, e.g. KIN-29, DAF-2, OCR-2 and calcium signaling, and circuit inputs from RMG mediated by NPR-1. Based on these findings, we propose an intriguing but speculative feedback modulatory circuit mechanism by which sensory perception of food and internal state signals may be coupled to regulate ADL-expressed chemoreceptors, which may allow animals to precisely regulate and fine-tune their chemosensory neuron responses as a function of feeding state.
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Affiliation(s)
- Matthew Gruner
- Department of Biology; University of Nevada ; Reno, NV USA
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44
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Guo M, Wu TH, Song YX, Ge MH, Su CM, Niu WP, Li LL, Xu ZJ, Ge CL, Al-Mhanawi MTH, Wu SP, Wu ZX. Reciprocal inhibition between sensory ASH and ASI neurons modulates nociception and avoidance in Caenorhabditis elegans. Nat Commun 2015; 6:5655. [PMID: 25585042 DOI: 10.1038/ncomms6655] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 10/24/2014] [Indexed: 02/02/2023] Open
Abstract
Sensory modulation is essential for animal sensations, behaviours and survival. Peripheral modulations of nociceptive sensations and aversive behaviours are poorly understood. Here we identify a biased cross-inhibitory neural circuit between ASH and ASI sensory neurons. This inhibition is essential to drive normal adaptive avoidance of a CuSO4 (Cu(2+)) challenge in Caenorhabditis elegans. In the circuit, ASHs respond to Cu(2+) robustly and suppress ASIs via electro-synaptically exciting octopaminergic RIC interneurons, which release octopamine (OA), and neuroendocrinally inhibit ASI by acting on the SER-3 receptor. In addition, ASIs sense Cu(2+) and permit a rapid onset of Cu(2+)-evoked responses in Cu(2+)-sensitive ADF neurons via neuropeptides possibly, to inhibit ASHs. ADFs function as interneurons to mediate ASI inhibition of ASHs by releasing serotonin (5-HT) that binds with the SER-5 receptor on ASHs. This elaborate modulation among sensory neurons via reciprocal inhibition fine-tunes the nociception and avoidance behaviour.
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Affiliation(s)
- Min Guo
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Tai-Hong Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Yan-Xue Song
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Ming-Hai Ge
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Chun-Ming Su
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Wei-Pin Niu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Lan-Lan Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Zi-Jing Xu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Chang-Li Ge
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Maha T H Al-Mhanawi
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
| | - Shi-Ping Wu
- School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073, China
| | - Zheng-Xing Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
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Wang D, Yu Y, Li Y, Wang Y, Wang D. Dopamine receptors antagonistically regulate behavioral choice between conflicting alternatives in C. elegans. PLoS One 2014; 9:e115985. [PMID: 25536037 PMCID: PMC4275273 DOI: 10.1371/journal.pone.0115985] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 12/03/2014] [Indexed: 11/18/2022] Open
Abstract
Caenorhabditis elegans is a useful model to study the neuronal or molecular basis for behavioral choice, a specific form of decision-making. Although it has been implied that both D1-like and D2-like dopamine receptors may contribute to the control of decision-making in mammals, the genetic interactions between D1-like and D2-like dopamine receptors in regulating decision-making are still largely unclear. In the present study, we investigated the molecular control of behavioral choice between conflicting alternatives (diacetyl and Cu2+) by D1-like and D2-like dopamine receptors and their possible genetic interactions with C. elegans as the assay system. In the behavioral choice assay system, mutation of dop-1 gene encoding D1-like dopamine receptor resulted in the enhanced tendency to cross the Cu2+ barrier compared with wild-type. In contrast, mutations of dop-2 or dop-3 gene encoding D2-like dopamine receptor caused the weak tendency to cross the Cu2+ barrier compared with wild-type. During the control of behavioral choice, DOP-3 antagonistically regulated the function of DOP-1. The behavioral choice phenotype of dop-2; dop-1dop-3 triple mutant further confirmed the possible antagonistic function of D2-like dopamine receptor on D1-like dopamine receptor in regulating behavioral choice. The genetic assays further demonstrate that DOP-3 might act through Gαo signaling pathway encoded by GOA-1 and EGL-10, and DOP-1 might act through Gαq signaling pathway encoded by EGL-30 and EAT-16 to regulate the behavioral choice. DOP-1 might function in cholinergic neurons to regulate the behavioral choice, whereas DOP-3 might function in GABAergic neurons, RIC, and SIA neurons to regulate the behavioral choice. In this study, we provide the genetic evidence to indicate the antagonistic relationship between D1-like dopamine receptor and D2-like dopamine receptor in regulating the decision-making of animals. Our data will be useful for understanding the complex functions of dopamine receptors in regulating decision-making in animals.
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Affiliation(s)
- Daoyong Wang
- Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Medical School of Southeast University, Nanjing, 210009, China
| | - Yonglin Yu
- Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Medical School of Southeast University, Nanjing, 210009, China
| | - Yinxia Li
- Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Medical School of Southeast University, Nanjing, 210009, China
| | - Yang Wang
- Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Medical School of Southeast University, Nanjing, 210009, China
| | - Dayong Wang
- Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Medical School of Southeast University, Nanjing, 210009, China
- * E-mail:
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Parida L, Neogi S, Padmanabhan V. Effect of temperature pre-exposure on the locomotion and chemotaxis of C. elegans. PLoS One 2014; 9:e111342. [PMID: 25360667 PMCID: PMC4216088 DOI: 10.1371/journal.pone.0111342] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/01/2014] [Indexed: 11/18/2022] Open
Abstract
The effect of temperature pre-exposure on locomotion and chemotaxis of the soil-dwelling nematode Caenorhabditis elegans has been extensively studied. The behavior of C. elegans was quantified using a simple harmonic curvature-based model. Animals showed increased levels of activity, compared to control worms, immediately after pre-exposure to 30 °C. This high level of activity in C. elegans translated into frequent turns by making 'complex' shapes, higher velocity of locomotion, and higher chemotaxis index (CI) in presence of a gradient of chemoattractant. The effect of pre-exposure was observed to be persistent for about 20 minutes after which the behavior (including velocity and CI) appeared to be comparable to that of control animals (maintained at 20 °C). Surprisingly, after 30 minutes of recovery, the behavior of C. elegans continued to deteriorate further below that of control worms with a drastic reduction in the curvature of the worms' body. A majority of these worms also showed negative chemotaxis index indicating a loss in their chemotaxis ability.
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Affiliation(s)
- Lipika Parida
- Department of Chemical Engineering, Indian Institute of Technology, Kharagpur, West Bengal, India
| | - Sudarsan Neogi
- Department of Chemical Engineering, Indian Institute of Technology, Kharagpur, West Bengal, India
| | - Venkat Padmanabhan
- Department of Chemical Engineering, Indian Institute of Technology, Kharagpur, West Bengal, India
- * E-mail:
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Gruner M, Nelson D, Winbush A, Hintz R, Ryu L, Chung SH, Kim K, Gabel CV, van der Linden AM. Feeding state, insulin and NPR-1 modulate chemoreceptor gene expression via integration of sensory and circuit inputs. PLoS Genet 2014; 10:e1004707. [PMID: 25357003 PMCID: PMC4214617 DOI: 10.1371/journal.pgen.1004707] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 08/26/2014] [Indexed: 12/24/2022] Open
Abstract
Feeding state and food availability can dramatically alter an animals' sensory response to chemicals in its environment. Dynamic changes in the expression of chemoreceptor genes may underlie some of these food and state-dependent changes in chemosensory behavior, but the mechanisms underlying these expression changes are unknown. Here, we identified a KIN-29 (SIK)-dependent chemoreceptor, srh-234, in C. elegans whose expression in the ADL sensory neuron type is regulated by integration of sensory and internal feeding state signals. We show that in addition to KIN-29, signaling is mediated by the DAF-2 insulin-like receptor, OCR-2 TRPV channel, and NPR-1 neuropeptide receptor. Cell-specific rescue experiments suggest that DAF-2 and OCR-2 act in ADL, while NPR-1 acts in the RMG interneurons. NPR-1-mediated regulation of srh-234 is dependent on gap-junctions, implying that circuit inputs regulate the expression of chemoreceptor genes in sensory neurons. Using physical and genetic manipulation of ADL neurons, we show that sensory inputs from food presence and ADL neural output regulate srh-234 expression. While KIN-29 and DAF-2 act primarily via the MEF-2 (MEF2) and DAF-16 (FOXO) transcription factors to regulate srh-234 expression in ADL neurons, OCR-2 and NPR-1 likely act via a calcium-dependent but MEF-2- and DAF-16-independent pathway. Together, our results suggest that sensory- and circuit-mediated regulation of chemoreceptor genes via multiple pathways may allow animals to precisely regulate and fine-tune their chemosensory responses as a function of internal and external conditions. Animals dramatically modify their chemosensory behaviors to attractive and noxious chemical stimuli when starved. This could allow them to alter and optimize their food-search strategies to increase their survival and reproduction. Changes in the gene expression of chemoreceptors specialized in detecting environmental stimuli is observed in fish, insects and nematodes, and may be a general mechanism underlying the changes in chemosensory behaviors observed in starved animals. To elucidate this mechanism, we have developed an in vivo reporter assay in C. elegans for monitoring the expression of a candidate chemoreceptor gene in a single sensory neuron type, called ADL, as a function of feeding state. Using this reporter assay, we show that sensory inputs into ADL and neural outputs from ADL, as well as inputs from the RMG interneuron, which is electrically connected to ADL, are required to fine-tune expression of chemoreceptor genes in ADL. Sensory and circuit-mediated regulation of chemoreceptor gene expression is dependent on multiple pathways, including the neuropeptide receptor, NPR-1, and the DAF-2 insulin-like receptor. Our results reveal mechanisms underlying chemoreceptor gene expression, and provide insight into how expression changes in chemoreceptor genes may contribute to changes in chemosensory behavior as a function of feeding state.
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Affiliation(s)
- Matthew Gruner
- Department of Biology, University of Nevada, Reno, Nevada, United States of America
| | - Dru Nelson
- Department of Biology, University of Nevada, Reno, Nevada, United States of America
| | - Ari Winbush
- Department of Biology, University of Nevada, Reno, Nevada, United States of America
| | - Rebecca Hintz
- Department of Agriculture, Nutrition and Veterinary Sciences, University of Nevada, Reno, Nevada, United States of America
| | - Leesun Ryu
- Department of Brain Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea
| | - Samuel H. Chung
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Boston University Photonics Center, Boston, Massachusetts, United States of America
| | - Kyuhyung Kim
- Department of Brain Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea
| | - Chrisopher V. Gabel
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Boston University Photonics Center, Boston, Massachusetts, United States of America
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Dopamine modulation of avoidance behavior in Caenorhabditis elegans requires the NMDA receptor NMR-1. PLoS One 2014; 9:e102958. [PMID: 25089710 PMCID: PMC4121140 DOI: 10.1371/journal.pone.0102958] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 06/26/2014] [Indexed: 01/01/2023] Open
Abstract
The nematode C. elegans utilizes a relatively simple neural circuit to mediate avoidance responses to noxious stimuli such as the volatile odorant octanol. This avoidance behavior is modulated by dopamine. cat-2 mutant animals that are deficient in dopamine biosynthesis have an increased response latency to octanol compared to wild type animals, and this defect can be fully restored with the application of exogenous dopamine. Because this avoidance behavior is mediated by glutamatergic signaling between sensory neurons and premotor interneurons, we investigated the genetic interactions between dopaminergic signaling and ionotropic glutamate receptors. cat-2 mutant animals lacking either the GLR-1 or GLR-2 AMPA/kainate receptors displayed an increased response latency to octanol, which could be restored via exogenous dopamine. However, whereas cat-2 mutant animals lacking the NMR-1 NMDA receptor had increased response latency to octanol they were insensitive to exogenous dopamine. Mutants that lacked both AMPA/kainate and NMDA receptors were also insensitive to exogenous dopamine. Our results indicate that dopamine modulation of octanol avoidance requires NMR-1, consistent with NMR-1 as a potential downstream signaling target for dopamine.
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The Function of Snodprot in the Cerato-Platanin Family fromDactylellina cionopagain Nematophagous Fungi. Biosci Biotechnol Biochem 2014; 76:1835-42. [DOI: 10.1271/bbb.120173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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50
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Hobert O. Development of left/right asymmetry in the Caenorhabditis elegans nervous system: From zygote to postmitotic neuron. Genesis 2014; 52:528-43. [DOI: 10.1002/dvg.22747] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 01/23/2014] [Accepted: 01/28/2014] [Indexed: 01/23/2023]
Affiliation(s)
- Oliver Hobert
- Department of Biochemistry and Molecular Biophysics; Howard Hughes Medical Institute, Columbia University Medical Center; New York New York
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