1
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Lee HK, Lee TY, Lee JI, Park KS, Yoon KH. Precise sensorimotor control impacts reproductive fitness of C. elegans in 3D environments. Neuroreport 2024; 35:123-128. [PMID: 38109381 PMCID: PMC10766090 DOI: 10.1097/wnr.0000000000001986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/20/2023]
Abstract
The ability of animals to sense and navigate towards relevant cues in complex and elaborate habitats is paramount for their survival and reproductive success. The nematode Caenorhabditis elegans uses a simple and elegant sensorimotor program to track odors in its environments. Whether this allows the worm to effectively navigate a complex environment and increase its evolutionary success has not been tested yet. We designed an assay to test whether C. elegans can track odors in a complex 3D environment. We then used a previously established 3D cultivation system to test whether defect in tracking odors to find food in a complex environment affected their brood size. We found that wild-type worms can accurately migrate toward a variety of odors in 3D. However, mutants of the muscarinic acetylcholine receptor GAR-3 which have a sensorimotor integration defect that results in a subtle navigational defect steering towards attractive odors, display decreased chemotaxis to the odor butanone not seen in the traditional 2D assay. We also show that the decreased ability to locate appetitive stimuli in 3D leads to reduced brood size not observed in the standard 2D culture conditions. Our study shows that mutations in genes previously overlooked in 2D conditions can have a significant impact in the natural habitat, and highlights the importance of considering the evolutionary selective pressures that have shaped the behavior, as well as the underlying genes and neural circuits.
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Affiliation(s)
- Hee Kyung Lee
- Department of Physiology, Yonsei University Wonju College of Medicine
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine
- Department of Global Medical Science, Yonsei University Wonju College of Medicine
| | - Tong Young Lee
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Mirae Campus, Wonju, South Korea
| | - Jin I. Lee
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Mirae Campus, Wonju, South Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine
- Department of Global Medical Science, Yonsei University Wonju College of Medicine
| | - Kyoung-hye Yoon
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine
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2
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von Mikecz A. Elegant Nematodes Improve Our Understanding of Human Neuronal Diseases, the Role of Pollutants and Strategies of Resilience. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:16755-16763. [PMID: 37874738 PMCID: PMC10634345 DOI: 10.1021/acs.est.3c04580] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/26/2023]
Abstract
The prevalence of neurodegenerative disorders such as Alzheimer's and Parkinson's disease are rising globally. The role of environmental pollution in neurodegeneration is largely unknown. Thus, this perspective advocates exposome research in C. elegans models of human diseases. The models express amyloid proteins such as Aβ, recapitulate the degeneration of specifically vulnerable neurons and allow for correlated neurobehavioral phenotyping throughout the entire life span of the nematode. Neurobehavioral traits like locomotion gaits, rigidity, or cognitive decline are quantifiable and carefully mimic key aspects of the human diseases. Underlying molecular pathways of neurodegeneration are elucidated in pollutant-exposed C. elegans Alzheimer's or Parkinson's models by transcriptomics (RNA-seq), mass spectrometry-based proteomics and omics addressing other biochemical traits. Validation of the identified disease pathways can be achieved by genome-wide association studies in matching human cohorts. A consistent One Health approach includes isolation of nematodes from contaminated sites and their comparative investigation by imaging, neurobehavioral profiling and single worm proteomics. C. elegans models of neurodegenerative diseases are likewise well-suited for high throughput methods that provide a promising strategy to identify resilience pathways of neurosafety and keep up with the number of pollutants, nonchemical exposome factors, and their interactions.
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Affiliation(s)
- Anna von Mikecz
- IUF − Leibniz Research Institute
of Environmental Medicine GmbH, Auf’m Hennekamp 50, 40225 Duesseldorf, Germany
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3
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Sheardown E, Mech AM, Petrazzini MEM, Leggieri A, Gidziela A, Hosseinian S, Sealy IM, Torres-Perez JV, Busch-Nentwich EM, Malanchini M, Brennan CH. Translational relevance of forward genetic screens in animal models for the study of psychiatric disease. Neurosci Biobehav Rev 2022; 135:104559. [PMID: 35124155 PMCID: PMC9016269 DOI: 10.1016/j.neubiorev.2022.104559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 12/10/2021] [Accepted: 02/01/2022] [Indexed: 12/16/2022]
Abstract
Psychiatric disorders represent a significant burden in our societies. Despite the convincing evidence pointing at gene and gene-environment interaction contributions, the role of genetics in the etiology of psychiatric disease is still poorly understood. Forward genetic screens in animal models have helped elucidate causal links. Here we discuss the application of mutagenesis-based forward genetic approaches in common animal model species: two invertebrates, nematodes (Caenorhabditis elegans) and fruit flies (Drosophila sp.); and two vertebrates, zebrafish (Danio rerio) and mice (Mus musculus), in relation to psychiatric disease. We also discuss the use of large scale genomic studies in human populations. Despite the advances using data from human populations, animal models coupled with next-generation sequencing strategies are still needed. Although with its own limitations, zebrafish possess characteristics that make them especially well-suited to forward genetic studies exploring the etiology of psychiatric disorders.
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Affiliation(s)
- Eva Sheardown
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Aleksandra M Mech
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | | | - Adele Leggieri
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Agnieszka Gidziela
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Saeedeh Hosseinian
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Ian M Sealy
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Department of Medicine, University of Cambridge, Cambridge, UK
| | - Jose V Torres-Perez
- UK Dementia Research Institute at Imperial College London and Department of Brain Sciences, Imperial College London, 86 Wood Lane, London W12 0BZ, UK
| | - Elisabeth M Busch-Nentwich
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Margherita Malanchini
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Caroline H Brennan
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK.
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4
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Hughes KJ, Vidal-Gadea AG. Methods for Modulating and Measuring Neuromuscular Exertion in C. elegans. Methods Mol Biol 2022; 2468:339-356. [PMID: 35320575 DOI: 10.1007/978-1-0716-2181-3_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The nematode C. elegans has been used widely to study the genetic and cellular basis of behavior. Yet the laboratory conditions under which it is typically studied offer only a narrow glimpse into the richness of natural behaviors this remarkable animal evolved over 500 million years of evolution. For example, burrowing behavior naturally occurs in the wild, but it remains understudied. Our group studies burrowing in an attempt to expand our understanding of the natural behavioral repertoire of C. elegans. Aside from being an interesting and tractable behavior, burrowing is experimentally useful and permits the titration of the muscular output exerted by C. elegans. Here we describe several burrowing assays that allow the modulation of muscular exertion. We used these to study both adaptive and pathological muscular processes such as muscle hypertrophy and dystrophy, respectively. We believe these assays will be of use for researchers studying the production of locomotion under normal and disease-challenged conditions.
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Affiliation(s)
- Kiley J Hughes
- School of Biological Sciences, Illinois State University, Normal, IL, USA
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5
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Molendijk J, Blazev R, Mills RJ, Ng YK, Watt KI, Chau D, Gregorevic P, Crouch PJ, Hilton JBW, Lisowski L, Zhang P, Reue K, Lusis AJ, Hudson JE, James DE, Seldin MM, Parker BL. Proteome-wide systems genetics identifies UFMylation as a regulator of skeletal muscle function. eLife 2022; 11:82951. [PMID: 36472367 PMCID: PMC9833826 DOI: 10.7554/elife.82951] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Improving muscle function has great potential to improve the quality of life. To identify novel regulators of skeletal muscle metabolism and function, we performed a proteomic analysis of gastrocnemius muscle from 73 genetically distinct inbred mouse strains, and integrated the data with previously acquired genomics and >300 molecular/phenotypic traits via quantitative trait loci mapping and correlation network analysis. These data identified thousands of associations between protein abundance and phenotypes and can be accessed online (https://muscle.coffeeprot.com/) to identify regulators of muscle function. We used this resource to prioritize targets for a functional genomic screen in human bioengineered skeletal muscle. This identified several negative regulators of muscle function including UFC1, an E2 ligase for protein UFMylation. We show UFMylation is up-regulated in a mouse model of amyotrophic lateral sclerosis, a disease that involves muscle atrophy. Furthermore, in vivo knockdown of UFMylation increased contraction force, implicating its role as a negative regulator of skeletal muscle function.
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Affiliation(s)
- Jeffrey Molendijk
- Department of Anatomy and Physiology, University of MelbourneMelbourneAustralia,Centre for Muscle Research, University of MelbourneMelbourneAustralia
| | - Ronnie Blazev
- Department of Anatomy and Physiology, University of MelbourneMelbourneAustralia,Centre for Muscle Research, University of MelbourneMelbourneAustralia
| | | | - Yaan-Kit Ng
- Department of Anatomy and Physiology, University of MelbourneMelbourneAustralia,Centre for Muscle Research, University of MelbourneMelbourneAustralia
| | - Kevin I Watt
- Department of Anatomy and Physiology, University of MelbourneMelbourneAustralia,Centre for Muscle Research, University of MelbourneMelbourneAustralia
| | - Daryn Chau
- Department of Biological Chemistry and Center for Epigenetics and Metabolism, University of California, IrvineIrvineUnited States
| | - Paul Gregorevic
- Department of Anatomy and Physiology, University of MelbourneMelbourneAustralia,Centre for Muscle Research, University of MelbourneMelbourneAustralia
| | - Peter J Crouch
- Department of Biochemistry and Pharmacology, University of MelbourneMelbourneAustralia
| | - James BW Hilton
- Department of Biochemistry and Pharmacology, University of MelbourneMelbourneAustralia
| | - Leszek Lisowski
- Children's Medical Research Institute, University of SydneySydneyAustralia,Military Institute of MedicineWarszawaPoland
| | - Peixiang Zhang
- Department of Human Genetics/Medicine, David Geffen School of Medicine, University of California, Los AngelesLos AngelesUnited States
| | - Karen Reue
- Department of Human Genetics/Medicine, David Geffen School of Medicine, University of California, Los AngelesLos AngelesUnited States
| | - Aldons J Lusis
- Department of Human Genetics/Medicine, David Geffen School of Medicine, University of California, Los AngelesLos AngelesUnited States,Department of Microbiology, Immunology and Molecular Genetics, University of California, Los AngelesLos AngelesUnited States
| | - James E Hudson
- QIMR Berghofer Medical Research InstituteBrisbaneAustralia
| | - David E James
- Charles Perkins Centre, School of Life and Environmental Science, School of Medical Science, University of SydneySydneyAustralia
| | - Marcus M Seldin
- Department of Biological Chemistry and Center for Epigenetics and Metabolism, University of California, IrvineIrvineUnited States
| | - Benjamin L Parker
- Department of Anatomy and Physiology, University of MelbourneMelbourneAustralia,Centre for Muscle Research, University of MelbourneMelbourneAustralia
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6
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Lesanpezeshki L, Qadota H, Darabad MN, Kashyap K, Lacerda CMR, Szewczyk NJ, Benian GM, Vanapalli SA. Investigating the correlation of muscle function tests and sarcomere organization in C. elegans. Skelet Muscle 2021; 11:20. [PMID: 34389048 PMCID: PMC8362255 DOI: 10.1186/s13395-021-00275-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 07/08/2021] [Indexed: 11/20/2022] Open
Abstract
Background Caenorhabditis elegans has been widely used as a model to study muscle structure and function. Its body wall muscle is functionally and structurally similar to vertebrate skeletal muscle with conserved molecular pathways contributing to sarcomere structure, and muscle function. However, a systematic investigation of the relationship between muscle force and sarcomere organization is lacking. Here, we investigate the contribution of various sarcomere proteins and membrane attachment components to muscle structure and function to introduce C. elegans as a model organism to study the genetic basis of muscle strength. Methods We employ two recently developed assays that involve exertion of muscle forces to investigate the correlation of muscle function to sarcomere organization. We utilized a microfluidic pillar-based platform called NemaFlex that quantifies the maximum exertable force and a burrowing assay that challenges the animals to move in three dimensions under a chemical stimulus. We selected 20 mutants with known defects in various substructures of sarcomeres and compared the physiological function of muscle proteins required for force generation and transmission. We also characterized the degree of sarcomere disorganization using immunostaining approaches. Results We find that mutants with genetic defects in thin filaments, thick filaments, and M-lines are generally weaker, and our assays are successful in detecting the functional changes in response to each sarcomere location tested. We find that the NemaFlex and burrowing assays are functionally distinct informing on different aspects of muscle physiology. Specifically, the burrowing assay has a larger bandwidth in phenotyping muscle mutants, because it could pick ten additional mutants impaired while exerting normal muscle force in NemaFlex. This enabled us to combine their readouts to develop an integrated muscle function score that was found to correlate with the score for muscle structure disorganization. Conclusions Our results highlight the suitability of NemaFlex and burrowing assays for evaluating muscle physiology of C. elegans. Using these approaches, we discuss the importance of the studied sarcomere proteins for muscle function and structure. The scoring methodology we have developed enhances the utility of C. elegans as a genetic model to study muscle function. Supplementary Information The online version contains supplementary material available at 10.1186/s13395-021-00275-4.
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Affiliation(s)
- Leila Lesanpezeshki
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, 79409, USA
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | | | - Karishma Kashyap
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Carla M R Lacerda
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, 79409, USA
| | - Nathaniel J Szewczyk
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Nottingham, United Kingdom & National Institute for Health Research Nottingham Biomedical Research Centre, Derby, DE22 3DT, UK.,Ohio Musculoskeletal and Neurological Institute (OMNI) and Department of Biomedical Sciences, Ohio University, Athens, OH, 45701, USA
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | - Siva A Vanapalli
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, 79409, USA.
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7
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Hrach HC, O'Brien S, Steber HS, Newbern J, Rawls A, Mangone M. Transcriptome changes during the initiation and progression of Duchenne muscular dystrophy in Caenorhabditis elegans. Hum Mol Genet 2021; 29:1607-1623. [PMID: 32227114 PMCID: PMC7322572 DOI: 10.1093/hmg/ddaa055] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 02/17/2020] [Accepted: 03/23/2020] [Indexed: 12/21/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal, X-linked disease characterized by progressive muscle degeneration. The condition is driven by nonsense and missense mutations in the dystrophin gene, leading to instability of the sarcolemma and skeletal muscle necrosis and atrophy. Resulting changes in muscle-specific gene expression that take place in dystrophin's absence remain largely uncharacterized, as they are potentially obscured by the chronic inflammation elicited by muscle damage in humans. Caenorhabditis elegans possess a mild inflammatory response that is not active in the muscle, and lack a satellite cell equivalent. This allows for the characterization of the transcriptome rearrangements affecting disease progression independently of inflammation and regeneration. In effort to better understand these dynamics, we have isolated and sequenced body muscle-specific transcriptomes from C. elegans lacking functional dystrophin at distinct stages of disease progression. We have identified an upregulation of genes involved in mitochondrial function early in disease progression, and an upregulation of genes related to muscle repair in later stages. Our results suggest that in C. elegans, dystrophin may have a signaling role early in development, and its absence may activate compensatory mechanisms that counteract muscle degradation caused by loss of dystrophin. We have also developed a temperature-based screening method for synthetic paralysis that can be used to rapidly identify genetic partners of dystrophin. Our results allow for the comprehensive identification of transcriptome changes that potentially serve as independent drivers of disease progression and may in turn allow for the identification of new therapeutic targets for the treatment of DMD.
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Affiliation(s)
- Heather C Hrach
- Molecular and Cellular Biology Graduate Program, School of Life Sciences, 427 East Tyler Mall, Tempe, AZ 85287 4501, USA.,Virginia G. Piper Center for Personalized Diagnostics, The Biodesign Institute at Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85281, USA
| | - Shannon O'Brien
- Virginia G. Piper Center for Personalized Diagnostics, The Biodesign Institute at Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85281, USA.,Barrett Honors College, Arizona State University, 751 E Lemon Mall, Tempe, AZ 85281, USA
| | - Hannah S Steber
- Barrett Honors College, Arizona State University, 751 E Lemon Mall, Tempe, AZ 85281, USA
| | - Jason Newbern
- School of Life Sciences, 427 East Tyler Mall, Tempe, AZ 85287 4501, USA
| | - Alan Rawls
- School of Life Sciences, 427 East Tyler Mall, Tempe, AZ 85287 4501, USA
| | - Marco Mangone
- Virginia G. Piper Center for Personalized Diagnostics, The Biodesign Institute at Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85281, USA
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8
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Ellwood RA, Piasecki M, Szewczyk NJ. Caenorhabditis elegans as a Model System for Duchenne Muscular Dystrophy. Int J Mol Sci 2021; 22:ijms22094891. [PMID: 34063069 PMCID: PMC8125261 DOI: 10.3390/ijms22094891] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/26/2021] [Accepted: 04/26/2021] [Indexed: 02/07/2023] Open
Abstract
The nematode worm Caenorhabditis elegans has been used extensively to enhance our understanding of the human neuromuscular disorder Duchenne Muscular Dystrophy (DMD). With new arising clinically relevant models, technologies and treatments, there is a need to reconcile the literature and collate the key findings associated with this model.
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Affiliation(s)
- Rebecca A. Ellwood
- Medical Research Council (MRC) Versus Arthritis, Centre for Musculoskeletal Ageing Research, Royal Derby Hospital, University of Nottingham, Derby DE22 3DT, UK; (R.A.E.); (M.P.)
- National Institute for Health Research, Nottingham Biomedical Research Centre, Derby DE22 3DT, UK
| | - Mathew Piasecki
- Medical Research Council (MRC) Versus Arthritis, Centre for Musculoskeletal Ageing Research, Royal Derby Hospital, University of Nottingham, Derby DE22 3DT, UK; (R.A.E.); (M.P.)
- National Institute for Health Research, Nottingham Biomedical Research Centre, Derby DE22 3DT, UK
| | - Nathaniel J. Szewczyk
- Medical Research Council (MRC) Versus Arthritis, Centre for Musculoskeletal Ageing Research, Royal Derby Hospital, University of Nottingham, Derby DE22 3DT, UK; (R.A.E.); (M.P.)
- National Institute for Health Research, Nottingham Biomedical Research Centre, Derby DE22 3DT, UK
- Ohio Musculoskeletal and Neurologic Institute, Ohio University, Athens, OH 45701, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
- Correspondence:
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9
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Schuch KN, Govindarajan LN, Guo Y, Baskoylu SN, Kim S, Kimia B, Serre T, Hart AC. Discriminating between sleep and exercise-induced fatigue using computer vision and behavioral genetics. J Neurogenet 2020; 34:453-465. [PMID: 32811254 DOI: 10.1080/01677063.2020.1804565] [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: 12/29/2022]
Abstract
Following prolonged swimming, Caenorhabditis elegans cycle between active swimming bouts and inactive quiescent bouts. Swimming is exercise for C. elegans and here we suggest that inactive bouts are a recovery state akin to fatigue. It is known that cGMP-dependent kinase (PKG) activity plays a conserved role in sleep, rest, and arousal. Using C. elegans EGL-4 PKG, we first validate a novel learning-based computer vision approach to automatically analyze C. elegans locomotory behavior and an edge detection program that is able to distinguish between activity and inactivity during swimming for long periods of time. We find that C. elegans EGL-4 PKG function impacts timing of exercise-induced quiescent (EIQ) bout onset, fractional quiescence, bout number, and bout duration, suggesting that previously described pathways are engaged during EIQ bouts. However, EIQ bouts are likely not sleep as animals are feeding during the majority of EIQ bouts. We find that genetic perturbation of neurons required for other C. elegans sleep states also does not alter EIQ dynamics. Additionally, we find that EIQ onset is sensitive to age and DAF-16 FOXO function. In summary, we have validated behavioral analysis software that enables a quantitative and detailed assessment of swimming behavior, including EIQ. We found novel EIQ defects in aged animals and animals with mutations in a gene involved in stress tolerance. We anticipate that further use of this software will facilitate the analysis of genes and pathways critical for fatigue and other C. elegans behaviors.
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Affiliation(s)
- Kelsey N Schuch
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Lakshmi Narasimhan Govindarajan
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, RI, USA
| | - Yuliang Guo
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, RI, USA
| | - Saba N Baskoylu
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,Department of Neuroscience, Brown University, Providence, RI, USA
| | - Sarah Kim
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,Department of Neuroscience, Brown University, Providence, RI, USA
| | - Benjamin Kimia
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,School of Engineering, Brown University, Providence, RI, USA
| | - Thomas Serre
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, RI, USA
| | - Anne C Hart
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.,Department of Neuroscience, Brown University, Providence, RI, USA
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10
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Lesanpezeshki L, Hewitt JE, Laranjeiro R, Antebi A, Driscoll M, Szewczyk NJ, Blawzdziewicz J, Lacerda CMR, Vanapalli SA. Pluronic gel-based burrowing assay for rapid assessment of neuromuscular health in C. elegans. Sci Rep 2019; 9:15246. [PMID: 31645584 PMCID: PMC6811592 DOI: 10.1038/s41598-019-51608-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/03/2019] [Indexed: 12/26/2022] Open
Abstract
Whole-organism phenotypic assays are central to the assessment of neuromuscular function and health in model organisms such as the nematode C. elegans. In this study, we report a new assay format for engaging C. elegans in burrowing that enables rapid assessment of nematode neuromuscular health. In contrast to agar environments that pose specific drawbacks for characterization of C. elegans burrowing ability, here we use the optically transparent and biocompatible Pluronic F-127 gel that transitions from liquid to gel at room temperature, enabling convenient and safe handling of animals. The burrowing assay methodology involves loading animals at the bottom of well plates, casting a liquid-phase of Pluronic on top that solidifies via a modest temperature upshift, enticing animals to reach the surface via chemotaxis to food, and quantifying the relative success animals have in reaching the chemoattractant. We study the influence of Pluronic concentration, gel height and chemoattractant choice to optimize assay performance. To demonstrate the simplicity of the assay workflow and versatility, we show its novel application in multiple areas including (i) evaluating muscle mutants with defects in dense bodies and/or M-lines (pfn-3, atn-1, uig-1, dyc-1, zyx-1, unc-95 and tln-1), (ii) tuning assay conditions to reveal changes in the mutant gei-8, (iii) sorting of fast burrowers in a genetically-uniform wild-type population for later quantitation of their distinct muscle gene expression, and (iv) testing proteotoxic animal models of Huntington and Parkinson’s disease. Results from our studies show that stimulating animals to navigate in a dense environment that offers mechanical resistance to three-dimensional locomotion challenges the neuromuscular system in a manner distinct from standard crawling and thrashing assays. Our simple and high throughput burrowing assay can provide insight into molecular mechanisms for maintenance of neuromuscular health and facilitate screening for therapeutic targets.
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Affiliation(s)
| | - Jennifer E Hewitt
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, USA.,Department of Molecular Genetics of Ageing, Max Planck Institute for Biology of Ageing, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Ricardo Laranjeiro
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Adam Antebi
- Department of Molecular Genetics of Ageing, Max Planck Institute for Biology of Ageing, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Nathaniel J Szewczyk
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Nottingham, United Kingdom & National Institute for Health Research Nottingham Biomedical Research Centre, Derby, UK
| | - Jerzy Blawzdziewicz
- Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, USA
| | - Carla M R Lacerda
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, USA
| | - Siva A Vanapalli
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, USA.
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11
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Byrne JJ, Soh MS, Chandhok G, Vijayaraghavan T, Teoh JS, Crawford S, Cobham AE, Yapa NMB, Mirth CK, Neumann B. Disruption of mitochondrial dynamics affects behaviour and lifespan in Caenorhabditis elegans. Cell Mol Life Sci 2019; 76:1967-1985. [PMID: 30840087 PMCID: PMC6478650 DOI: 10.1007/s00018-019-03024-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 01/11/2019] [Accepted: 01/22/2019] [Indexed: 01/29/2023]
Abstract
Mitochondria are essential components of eukaryotic cells, carrying out critical physiological processes that include energy production and calcium buffering. Consequently, mitochondrial dysfunction is associated with a range of human diseases. Fundamental to their function is the ability to transition through fission and fusion states, which is regulated by several GTPases. Here, we have developed new methods for the non-subjective quantification of mitochondrial morphology in muscle and neuronal cells of Caenorhabditis elegans. Using these techniques, we uncover surprising tissue-specific differences in mitochondrial morphology when fusion or fission proteins are absent. From ultrastructural analysis, we reveal a novel role for the fusion protein FZO-1/mitofusin 2 in regulating the structure of the inner mitochondrial membrane. Moreover, we have determined the influence of the individual mitochondrial fission (DRP-1/DRP1) and fusion (FZO-1/mitofusin 1,2; EAT-3/OPA1) proteins on animal behaviour and lifespan. We show that loss of these mitochondrial fusion or fission regulators induced age-dependent and progressive deficits in animal movement, as well as in muscle and neuronal function. Our results reveal that disruption of fusion induces more profound defects than lack of fission on animal behaviour and tissue function, and imply that while fusion is required throughout life, fission is more important later in life likely to combat ageing-associated stressors. Furthermore, our data demonstrate that mitochondrial function is not strictly dependent on morphology, with no correlation found between morphological changes and behavioural defects. Surprisingly, we find that disruption of either mitochondrial fission or fusion significantly reduces median lifespan, but maximal lifespan is unchanged, demonstrating that mitochondrial dynamics play an important role in limiting variance in longevity across isogenic populations. Overall, our study provides important new insights into the central role of mitochondrial dynamics in maintaining organismal health.
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Affiliation(s)
- Joseph J Byrne
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Ming S Soh
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Gursimran Chandhok
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Tarika Vijayaraghavan
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Jean-Sébastien Teoh
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Simon Crawford
- Monash Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Melbourne, VIC, 3800, Australia
| | - Ansa E Cobham
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Nethmi M B Yapa
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Brent Neumann
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia.
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12
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Physical exertion exacerbates decline in the musculature of an animal model of Duchenne muscular dystrophy. Proc Natl Acad Sci U S A 2019; 116:3508-3517. [PMID: 30755520 DOI: 10.1073/pnas.1811379116] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disorder caused by loss of the protein dystrophin. In humans, DMD has early onset, causes developmental delays, muscle necrosis, loss of ambulation, and death. Current animal models have been challenged by their inability to model the early onset and severity of the disease. It remains unresolved whether increased sarcoplasmic calcium observed in dystrophic muscles follows or leads the mechanical insults caused by the muscle's disrupted contractile machinery. This knowledge has important implications for patients, as potential physiotherapeutic treatments may either help or exacerbate symptoms, depending on how dystrophic muscles differ from healthy ones. Recently we showed how burrowing dystrophic (dys-1) C. elegans recapitulate many salient phenotypes of DMD, including loss of mobility and muscle necrosis. Here, we report that dys-1 worms display early pathogenesis, including dysregulated sarcoplasmic calcium and increased lethality. Sarcoplasmic calcium dysregulation in dys-1 worms precedes overt structural phenotypes (e.g., mitochondrial, and contractile machinery damage) and can be mitigated by reducing calmodulin expression. To learn how dystrophic musculature responds to altered physical activity, we cultivated dys-1 animals in environments requiring high intensity or high frequency of muscle exertion during locomotion. We find that several muscular parameters (e.g., size) improve with increased activity. However, longevity in dystrophic animals was negatively associated with muscular exertion, regardless of effort duration. The high degree of phenotypic conservation between dystrophic worms and humans provides a unique opportunity to gain insight into the pathology of the disease as well as the initial assessment of potential treatment strategies.
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13
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Hewitt JE, Pollard AK, Lesanpezeshki L, Deane CS, Gaffney CJ, Etheridge T, Szewczyk NJ, Vanapalli SA. Muscle strength deficiency and mitochondrial dysfunction in a muscular dystrophy model of Caenorhabditis elegans and its functional response to drugs. Dis Model Mech 2018; 11:dmm036137. [PMID: 30396907 PMCID: PMC6307913 DOI: 10.1242/dmm.036137] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/30/2018] [Indexed: 12/31/2022] Open
Abstract
Muscle strength is a key clinical parameter used to monitor the progression of human muscular dystrophies, including Duchenne and Becker muscular dystrophies. Although Caenorhabditis elegans is an established genetic model for studying the mechanisms and treatments of muscular dystrophies, analogous strength-based measurements in this disease model are lacking. Here, we describe the first demonstration of the direct measurement of muscular strength in dystrophin-deficient C. elegans mutants using a micropillar-based force measurement system called NemaFlex. We show that dys-1(eg33) mutants, but not dys-1(cx18) mutants, are significantly weaker than their wild-type counterparts in early adulthood, cannot thrash in liquid at wild-type rates, display mitochondrial network fragmentation in the body wall muscles, and have an abnormally high baseline mitochondrial respiration. Furthermore, treatment with prednisone, the standard treatment for muscular dystrophy in humans, and melatonin both improve muscular strength, thrashing rate and mitochondrial network integrity in dys-1(eg33), and prednisone treatment also returns baseline respiration to normal levels. Thus, our results demonstrate that the dys-1(eg33) strain is more clinically relevant than dys-1(cx18) for muscular dystrophy studies in C. elegans This finding, in combination with the novel NemaFlex platform, can be used as an efficient workflow for identifying candidate compounds that can improve strength in the C. elegans muscular dystrophy model. Our study also lays the foundation for further probing of the mechanism of muscle function loss in dystrophin-deficient C. elegans, leading to knowledge translatable to human muscular dystrophy.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Jennifer E Hewitt
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA
| | - Amelia K Pollard
- MRC/ARUK Centre for Musculoskeletal Ageing Research, Royal Derby Hospital, University of Nottingham & National Institute for Health Research Nottingham Biomedical Research Centre, Derby, UK
| | - Leila Lesanpezeshki
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA
| | - Colleen S Deane
- Sport and Health Sciences, University of Exeter, St Luke's Campus, Exeter EX1 2LU, UK
| | - Christopher J Gaffney
- Sport and Health Sciences, University of Exeter, St Luke's Campus, Exeter EX1 2LU, UK
- Lancaster Medical School, Furness College, Lancaster University, Lancaster LA1 4YG, UK
| | - Timothy Etheridge
- Sport and Health Sciences, University of Exeter, St Luke's Campus, Exeter EX1 2LU, UK
| | - Nathaniel J Szewczyk
- MRC/ARUK Centre for Musculoskeletal Ageing Research, Royal Derby Hospital, University of Nottingham & National Institute for Health Research Nottingham Biomedical Research Centre, Derby, UK
| | - Siva A Vanapalli
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA
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White J. Clues to basis of exploratory behaviour of the C. elegans snout from head somatotropy. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2017.0367. [PMID: 30201833 DOI: 10.1098/rstb.2017.0367] [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] [Accepted: 07/04/2018] [Indexed: 12/16/2022] Open
Abstract
Wave propagation during locomotory movements of Caenorhabditis elegans is constrained to a single dorso/ventral plane. By contrast, the tip of the head (snout) can make rapid exploratory movements in all directions relative to the body axis. These extra degrees of freedom are probably important for animals to seek and identify desirable passages in the interstices of the three-dimensional matrix of soil particles, their usual habitat. The differences in degrees of freedom of movement between snout and body are reflected in the innervation of the musculature. Along the length of the body, the two quadrants of dorsal muscle receive common innervation as do the two quadrants of ventral muscle. By contrast, muscles in the snout have an octagonal arrangement of innervation. It is likely that the exploratory behaviour of the snout is mediated by octant-specific motor and sensory neurons, together with their associated interneurons. The well-defined anatomical structure and neural circuitry of the snout together with behavioural observations should facilitate the implementation of models of the neural basis of exploratory movements, which could lead to an understanding of the basis of this relatively complex behaviour, a behaviour that has similarities to foraging in some vertebrates.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling C. elegans at cellular resolution'.
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Affiliation(s)
- John White
- Laboratory of Cell and Molecular Biology, University of Wisconsin, Madison, WI, USA
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15
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Roll maneuvers are essential for active reorientation of Caenorhabditis elegans in 3D media. Proc Natl Acad Sci U S A 2018; 115:E3616-E3625. [PMID: 29618610 DOI: 10.1073/pnas.1706754115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Locomotion of the nematode Caenorhabditis elegans is a key observable used in investigations ranging from behavior to neuroscience to aging. However, while the natural environment of this model organism is 3D, quantitative investigations of its locomotion have been mostly limited to 2D motion. Here, we present a quantitative analysis of how the nematode reorients itself in 3D media. We identify a unique behavioral state of C. elegans-a roll maneuver-which is an essential component of 3D locomotion in burrowing and swimming. The rolls, associated with nonzero torsion of the nematode body, result in rotation of the plane of dorsoventral body undulations about the symmetry axis of the trajectory. When combined with planar turns in a new undulation plane, the rolls allow the nematode to reorient its body in any direction, thus enabling complete exploration of 3D space. The rolls observed in swimming are much faster than the ones in burrowing; we show that this difference stems from a purely hydrodynamic enhancement mechanism and not from a gait change or an increase in the body torsion. This result demonstrates that hydrodynamic viscous forces can enhance 3D reorientation in undulatory locomotion, in contrast to known hydrodynamic hindrance of both forward motion and planar turns.
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16
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Parry LA, Boggiani PC, Condon DJ, Garwood RJ, Leme JDM, McIlroy D, Brasier MD, Trindade R, Campanha GAC, Pacheco MLAF, Diniz CQC, Liu AG. Ichnological evidence for meiofaunal bilaterians from the terminal Ediacaran and earliest Cambrian of Brazil. Nat Ecol Evol 2017; 1:1455-1464. [DOI: 10.1038/s41559-017-0301-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 07/28/2017] [Indexed: 11/09/2022]
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17
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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: 0] [Impact Index Per Article: 0] [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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18
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Schmeisser K, Parker JA. Worms on the spectrum - C. elegans models in autism research. Exp Neurol 2017; 299:199-206. [PMID: 28434869 DOI: 10.1016/j.expneurol.2017.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/10/2017] [Accepted: 04/18/2017] [Indexed: 12/13/2022]
Abstract
The small non-parasitic nematode Caenorhabditis elegans is widely used in neuroscience thanks to its well-understood development and lineage of the nervous system. Furthermore, C. elegans has been used to model many human developmental and neurological conditions to better understand disease mechanisms and identify potential therapeutic strategies. Autism spectrum disorder (ASD) is the most prevalent of all neurodevelopmental disorders, and the C. elegans system may provide opportunities to learn more about this complex disorder. Since basic cell biology and biochemistry of the C. elegans nervous system is generally very similar to mammals, cellular or molecular phenotypes can be investigated, along with a repertoire of behaviours. For instance, worms have contributed greatly to the understanding of mechanisms underlying mutations in genes coding for synaptic proteins such as neuroligin and neurexin. Using worms to model neurodevelopmental disorders like ASD is an emerging topic that harbours great, untapped potential. This review summarizes the numerous contributions of C. elegans to the field of neurodevelopment and introduces the nematode system as a potential research tool to study essential roles of genes associated with ASD.
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Affiliation(s)
- Kathrin Schmeisser
- Centre de Recherche du Centre Hospitalier de l'Université de Montreál (CRCHUM), 900 St-Denis Street, Montreál, Queb́ec H2X 0A9, Canada
| | - J Alex Parker
- Centre de Recherche du Centre Hospitalier de l'Université de Montreál (CRCHUM), 900 St-Denis Street, Montreál, Queb́ec H2X 0A9, Canada; Department of Neuroscience, Université de Montreál, 2960 Chemin de la Tour, Montreál, Queb́ec H3T 1J4, Canada.
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19
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Schwarz J, Bringmann H. Analysis of the NK2 homeobox gene ceh-24 reveals sublateral motor neuron control of left-right turning during sleep. eLife 2017; 6. [PMID: 28244369 PMCID: PMC5384828 DOI: 10.7554/elife.24846] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 02/26/2017] [Indexed: 11/30/2022] Open
Abstract
Sleep is a behavior that is found in all animals that have a nervous system and that have been studied carefully. In Caenorhabditis elegans larvae, sleep is associated with a turning behavior, called flipping, in which animals rotate 180° about their longitudinal axis. However, the molecular and neural substrates of this enigmatic behavior are not known. Here, we identified the conserved NK-2 homeobox gene ceh-24 to be crucially required for flipping. ceh-24 is required for the formation of processes and for cholinergic function of sublateral motor neurons, which separately innervate the four body muscle quadrants. Knockdown of cholinergic function in a subset of these sublateral neurons, the SIAs, abolishes flipping. The SIAs depolarize during flipping and their optogenetic activation induces flipping in a fraction of events. Thus, we identified the sublateral SIA neurons to control the three-dimensional movements of flipping. These neurons may also control other types of motion. DOI:http://dx.doi.org/10.7554/eLife.24846.001 Although sleeping individuals do not move voluntarily, they are not completely immobile. Both people and animals regularly change position in their sleep, but it is not known why these movements occur or what regulates them. One of the simplest animals known to require sleep is the nematode worm Caenorhabditis elegans, which is often used by researchers to study the molecular basis of behavior. In common with more complex animals, worms go to sleep lying on either their left or right side and then switch periodically between the two. This “flipping” behavior is typically not seen outside of sleep. By screening worms with mutations in different genes, Schwarz and Bringmann identified one mutant that does not flip during sleep. The mutant lacked a gene called ceh-24, which is normally active in a set of four neurons known as SIAs. These are a type of motor neuron; that is, neurons that control the contraction of muscles. The body wall muscles of C. elegans run along the length of its body and are organized into “quadrants” that each cover a quarter of the worm. Schwarz and Bringmann show that unlike other C. elegans motor neurons, SIA neurons control each quadrant separately. By activating specific SIA neurons the worms can contract the muscles on each side of the body independently, and thereby flip from one side to the other. Further investigation revealed that the SIA motor neurons can also control other types of complex movement. Additional experiments are now needed to determine how the neurons support these behaviors. Another challenge will be to work out the purpose of posture changes during sleep for C. elegans and other animals. DOI:http://dx.doi.org/10.7554/eLife.24846.002
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Affiliation(s)
- Juliane Schwarz
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Henrik Bringmann
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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20
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Nanoscale imaging and characterization of Caenorhabditis elegans epicuticle using atomic force microscopy. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 13:483-491. [DOI: 10.1016/j.nano.2016.10.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/14/2016] [Accepted: 10/07/2016] [Indexed: 12/21/2022]
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21
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Hunt PR. The C. elegans model in toxicity testing. J Appl Toxicol 2017; 37:50-59. [PMID: 27443595 PMCID: PMC5132335 DOI: 10.1002/jat.3357] [Citation(s) in RCA: 296] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 05/20/2016] [Accepted: 05/21/2016] [Indexed: 12/25/2022]
Abstract
Caenorhabditis elegans is a small nematode that can be maintained at low cost and handled using standard in vitro techniques. Unlike toxicity testing using cell cultures, C. elegans toxicity assays provide data from a whole animal with intact and metabolically active digestive, reproductive, endocrine, sensory and neuromuscular systems. Toxicity ranking screens in C. elegans have repeatedly been shown to be as predictive of rat LD50 ranking as mouse LD50 ranking. Additionally, many instances of conservation of mode of toxic action have been noted between C. elegans and mammals. These consistent correlations make the case for inclusion of C. elegans assays in early safety testing and as one component in tiered or integrated toxicity testing strategies, but do not indicate that nematodes alone can replace data from mammals for hazard evaluation. As with cell cultures, good C. elegans culture practice (GCeCP) is essential for reliable results. This article reviews C. elegans use in various toxicity assays, the C. elegans model's strengths and limitations for use in predictive toxicology, and GCeCP. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Journal of Applied Toxicology published by John Wiley & Sons Ltd.
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22
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Lee TY, Yoon KH, Lee JI. NGT-3D: a simple nematode cultivation system to study Caenorhabditis elegans biology in 3D. Biol Open 2016; 5:529-34. [PMID: 26962047 PMCID: PMC4890662 DOI: 10.1242/bio.015743] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nematode Caenorhabditiselegans is one of the premier experimental model organisms today. In the laboratory, they display characteristic development, fertility, and behaviors in a two dimensional habitat. In nature, however, C. elegans is found in three dimensional environments such as rotting fruit. To investigate the biology of C. elegans in a 3D controlled environment we designed a nematode cultivation habitat which we term the nematode growth tube or NGT-3D. NGT-3D allows for the growth of both nematodes and the bacteria they consume. Worms show comparable rates of growth, reproduction and lifespan when bacterial colonies in the 3D matrix are abundant. However, when bacteria are sparse, growth and brood size fail to reach levels observed in standard 2D plates. Using NGT-3D we observe drastic deficits in fertility in a sensory mutant in 3D compared to 2D, and this defect was likely due to an inability to locate bacteria. Overall, NGT-3D will sharpen our understanding of nematode biology and allow scientists to investigate questions of nematode ecology and evolutionary fitness in the laboratory. Summary: We have designed a three dimensional nematode habitat for use in the lab, called NGT-3D, where growth, fertility and lifespan are comparable with the traditional two dimensional lab environment.
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Affiliation(s)
- Tong Young Lee
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Wonju 220-710, South Korea
| | - Kyoung-Hye Yoon
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Wonju 220-710, South Korea
| | - Jin Il Lee
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Wonju 220-710, South Korea
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23
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Bainbridge C, Schuler A, Vidal-Gadea AG. Method for the assessment of neuromuscular integrity and burrowing choice in vermiform animals. J Neurosci Methods 2016; 264:40-46. [PMID: 26947253 DOI: 10.1016/j.jneumeth.2016.02.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/26/2016] [Accepted: 02/29/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND The study of locomotion in vermiform animals has largely been restricted to animals crawling on agar surfaces. While this has been fruitful in the study of neuronal basis of disease and behavior, the reduced physical challenge posed by these environments has prevented these organisms from being equally successful in the study of neuromuscular diseases. Our burrowing assay allowed us to study the effects of muscular exertion on locomotion and muscle degeneration during disease (Beron et al., 2015), as well as the natural burrowing preference of diverse Caenorhabditis elegans strains (Vidal-Gadea et al., 2015). NEW METHOD We describe a simple, rapid, and affordable set of assays to study the burrowing behavior of nematodes and other vermiform organisms which permits the titration of muscular exertion in test animals. RESULTS We show that our burrowing assay design is versatile and can be adapted for use in widely different experimental paradigms. COMPARISON WITH EXISTING METHOD(S) Previous assays for the study of neuromuscular integrity in nematodes relied on movement through facile and homogeneous environments. The ability of modulating substrate density allows our burrowing assay to be used to separate animal populations where muscular fitness or health are not visible differentiable by standard techniques. CONCLUSION The simplicity, versatility, and potential for greatly facilitating the study of previously challenging neuromuscular disorders makes this assay a valuable addition that overcomes many of the limitations inherent to traditional behavioral tests of vermiform locomotion.
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Affiliation(s)
- C Bainbridge
- School of Biological Sciences, Illinois State University, 339 Science Laboratory Building, Normal, IL 61790-4120, USA
| | - A Schuler
- School of Biological Sciences, Illinois State University, 339 Science Laboratory Building, Normal, IL 61790-4120, USA
| | - A G Vidal-Gadea
- School of Biological Sciences, Illinois State University, 339 Science Laboratory Building, Normal, IL 61790-4120, USA.
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24
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Vidal-Gadea A, Ward K, Beron C, Ghorashian N, Gokce S, Russell J, Truong N, Parikh A, Gadea O, Ben-Yakar A, Pierce-Shimomura J. Magnetosensitive neurons mediate geomagnetic orientation in Caenorhabditis elegans. eLife 2015; 4:e07493. [PMID: 26083711 PMCID: PMC4525075 DOI: 10.7554/elife.07493] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 06/16/2015] [Indexed: 11/13/2022] Open
Abstract
Many organisms spanning from bacteria to mammals orient to the earth's magnetic field. For a few animals, central neurons responsive to earth-strength magnetic fields have been identified; however, magnetosensory neurons have yet to be identified in any animal. We show that the nematode Caenorhabditis elegans orients to the earth's magnetic field during vertical burrowing migrations. Well-fed worms migrated up, while starved worms migrated down. Populations isolated from around the world, migrated at angles to the magnetic vector that would optimize vertical translation in their native soil, with northern- and southern-hemisphere worms displaying opposite migratory preferences. Magnetic orientation and vertical migrations required the TAX-4 cyclic nucleotide-gated ion channel in the AFD sensory neuron pair. Calcium imaging showed that these neurons respond to magnetic fields even without synaptic input. C. elegans may have adapted magnetic orientation to simplify their vertical burrowing migration by reducing the orientation task from three dimensions to one.
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Affiliation(s)
- Andrés Vidal-Gadea
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
| | - Kristi Ward
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
| | - Celia Beron
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
| | - Navid Ghorashian
- Department of Mechanical Engineering, University of Texas at Austin, Austin, United States
| | - Sertan Gokce
- Department of Electrical Engineering, University of Texas at Austin, Austin, United States
| | - Joshua Russell
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
| | - Nicholas Truong
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
| | - Adhishri Parikh
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
| | - Otilia Gadea
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
| | - Adela Ben-Yakar
- Department of Mechanical Engineering, University of Texas at Austin, Austin, United States
| | - Jonathan Pierce-Shimomura
- Department of Neuroscience; Center for Brain, Behavior and Evolution; Center for Learning and Memory; Waggoner Center for Alcohol and Addiction Research; Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, United States
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