A Dynamic Body Model of the NematodeC. eleganswith Neural Oscillators

2005 ◽  
Vol 17 (3) ◽  
pp. 318-326 ◽  
Author(s):  
Michiyo Suzuki ◽  
◽  
Takeshi Goto ◽  
Toshio Tsuji ◽  
Hisao Ohtake ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Motor Control ◽  
Caenorhabditis Elegans ◽  
Neural Circuit ◽  
Rhythmic Movement ◽  
Circuit Model ◽  
Neural Oscillators ◽  
C Elegans ◽  
Body Model ◽  
Multicellular Organisms

The nematode <I>Caenorhabditis elegans (C. elegans)</I>, a relatively simple organism in structure, is one of the most well-studied multicellular organisms. We developed a <I>virtual C. elegans</I> based on the actual organism to analyze motor control. We propose a dynamic body model, including muscles, controlled by a neural circuit model based on the actual nematode. The model uses neural oscillators to generate rhythmic movement. Computer simulation confirmed that the <I>virtual C. elegans</I> realizes motor control similar qualitatively to that of the actual organism. Specified classes of neurons are killed in the neural circuit model corresponding to actual <I>unc</I> mutants, demonstrating that resulting movement of the <I>virtual C. elegans</I> resembles that of actual mutants.

scholarly journals Regulation of the mitosis/meiosis decision in the Caenorhabditis elegans germline

2003 ◽  
Vol 358 (1436) ◽  
pp. 1359-1362 ◽  
Author(s):  
Sarah L. Crittenden ◽  
Christian R. Eckmann ◽  
Liaoteng Wang ◽  
David S. Bernstein ◽  
Marvin Wickens ◽  
...  
Keyword(s):  
Stem Cells ◽  
Caenorhabditis Elegans ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Germline Stem Cells ◽  
Puf Proteins ◽  
C Elegans ◽  
Transcriptional Regulatory ◽  
Mitotic Proliferation ◽  
Multicellular Organisms

During the development of multicellular organisms, the processes of growth and differentiation are kept in balance to generate and maintain tissues and organs of the correct size, shape and cellular composition. We have investigated the molecular controls of growth and differentiation in the Caenorhabditis elegans germline. A single somatic cell, called the distal tip cell, promotes mitotic proliferation in the adjacent germline by GLP–1/Notch signalling. Within the germline, the decisions between mitosis and meiosis and between spermatogenesis and oogenesis are controlled by a group of conserved RNA regulators. FBF, a member of the PUF (for Pumilio and FBF) family of RNA–binding proteins, promotes mitosis by repressing gld–1 mRNA activity; the GLD–1, GLD–2, GLD–3 and NOS–3 proteins promote entry into meiosis by regulating mRNAs that remain unknown. The regulatory balance between opposing FBF and GLD activities is crucial for controlling the extent of germline proliferation. PUF proteins regulate germline stem cells in both Drosophila and C. elegans and are localized to germline stem cells of the mammalian testis. Therefore, this post–transcriptional regulatory switch may be an ancient mechanism for controlling maintenance of stem cells versus differentiation.

scholarly journals Distributed Rhythm Generators Underlie Caenorhabditis elegans Forward Locomotion

2017 ◽  
Author(s):  
Anthony D. Fouad ◽  
Shelly Teng ◽  
Julian R. Mark ◽  
Alice Liu ◽  
Pilar Alvarez-Illera ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Motor Neurons ◽  
Animal Behavior ◽  
Rhythm Generation ◽  
Rhythmic Movements ◽  
Neural Oscillators ◽  
Motor Circuit ◽  
C Elegans ◽  
Body Regions ◽  
Forward Locomotion

ABSTRACTCoordinated rhythmic movements are ubiquitous in animal behavior. In many organisms, chains of neural oscillators underlie the generation of these rhythms. In C. elegans, locomotor wave generation has been poorly understood; in particular, it is unclear where in the circuit rhythms are generated, and whether there exists more than one such generator. We used optogenetic and ablation experiments to probe the nature of rhythm generation in the locomotor circuit. We found that multiple sections of forward locomotor circuitry are capable of independently generating rhythms. By perturbing different components of the motor circuit, we localize the source of secondary rhythms to cholinergic motor neurons in the midbody. Using rhythmic optogenetic perturbation we demonstrate bidirectional entrainment of oscillations between different body regions. These results show that, as in many other vertebrates and invertebrates, the C. elegans motor circuit contains multiple oscillators that coordinate activity to generate behavior.

scholarly journals The functional repertoire encoded within the native microbiome of the model nematode Caenorhabditis elegans

2019 ◽  
Author(s):  
Johannes Zimmermann ◽  
Nancy Obeng ◽  
Wentao Yang ◽  
Barbara Pees ◽  
Carola Petersen ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Integrative Approach ◽  
Metabolic Modelling ◽  
Bacterial Physiology ◽  
C Elegans ◽  
Pyruvate Fermentation ◽  
Bacterial Microbiome ◽  
Multicellular Organisms ◽  
Taxonomic Characterization

AbstractThe microbiome is generally assumed to have a substantial influence on the biology of multicellular organisms. The exact functional contributions of the microbes are often unclear and cannot be inferred easily from 16S rRNA genotyping, which is commonly used for taxonomic characterization of the bacterial associates. In order to bridge this knowledge gap, we here analyzed the metabolic competences of the native microbiome of the model nematode Caenorhabditis elegans. We integrated whole genome sequences of 77 bacterial microbiome members with metabolic modelling and experimental characterization of bacterial physiology. We found that, as a community, the microbiome can synthesize all essential nutrients for C. elegans. Both metabolic models and experimental analyses further revealed that nutrient context can influence how bacteria interact within the microbiome. We identified key bacterial traits that are likely to influence the microbe’s ability to colonize C. elegans (e.g., pyruvate fermentation to acetoin) and the resulting effects on nematode fitness (e.g., hydroxyproline degradation). Considering that the microbiome is usually neglected in the comprehensive research on this nematode, the resource presented here will help our understanding of C. elegans biology in a more natural context. Our integrative approach moreover provides a novel, general framework to dissect microbiome-mediated functions.

scholarly journals Functional Requirement for Histone Deacetylase 1 in Caenorhabditis elegans Gonadogenesis

2002 ◽  
Vol 22 (9) ◽  
pp. 3024-3034 ◽  
Author(s):  
Pascale Dufourcq ◽  
Martin Victor ◽  
Frédérique Gay ◽  
Dominica Calvo ◽  
Jonathan Hodgkin ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Histone Deacetylase ◽  
Histone Deacetylases ◽  
Regulation Of Gene Expression ◽  
Notch Signaling Pathway ◽  
Transcriptional Repressors ◽  
Vulval Development ◽  
C Elegans ◽  
Histone Deacetylase 1 ◽  
Multicellular Organisms

ABSTRACT Histone acetylation and deacetylation have been implicated in the regulation of gene expression. Molecular studies have shown that histone deacetylases (HDACs) function as transcriptional repressors. However, very little is known about their roles during development in multicellular organisms. We previously demonstrated that inhibition of maternal and zygotic expression of histone deacetylase 1 (HDA-1) causes embryonic lethality in Caenorhabditis elegans. Here, we report the identification of an hda-1 genetic mutant which has also been called a gon-10 mutant (for gonadogenesis defective 10) and show that loss of HDA-1 zygotic expression results in specific postembryonic defects in gonadogenesis and vulval development. We provide evidence that the lag-2 gene, which plays a role in gonadogenesis and vulval development and encodes a Notch ligand, is derepressed in gon-10 animals, suggesting that lag-2 may be a target of HDA-1. Our findings reveal a novel and specific function for the ubiquitously expressed HDA-1 in C. elegans gonadogenesis and place hda-1 in the Notch signaling pathway.

scholarly journals Loss of CaMKI function disrupts salt aversive learning in C. elegans

2017 ◽  
Author(s):  
Jana P. Lim ◽  
Holger Fehlauer ◽  
Dominique A. Glauser ◽  
Anne Brunet ◽  
Miriam B. Goodman
Keyword(s):  
Caenorhabditis Elegans ◽  
Behavioral Plasticity ◽  
Neural Circuit ◽  
Aversive Learning ◽  
Learning Behavior ◽  
C Elegans ◽  
Calcium Calmodulin Dependent ◽  
Genetic Components ◽  
High Concentrations ◽  
Sensory Evoked

AbstractThe ability to adapt behavior to environmental fluctuations is critical for survival of organisms ranging from invertebrates to mammals. Caenorhabditis elegans can learn to avoid sodium chloride when it is paired with starvation. This behavior is likely advantageous to avoid areas without food. While some genes have been implicated in this salt aversive learning behavior, critical genetic components, and the neural circuit in which they act, remain elusive. Here, we show that the sole worm ortholog of mammalian CaMKI/IV, CMK-1, is essential for salt aversive learning behavior in C. elegans. We find that CMK-1 acts in the primary salt-sensing ASE neurons to regulate this behavior. By characterizing the intracellular calcium dynamics in ASE neurons using microfluidics, we find that loss of cmk-1 leads to an altered pattern of sensory-evoked calcium responses that may underlie salt aversive learning. Our study implicates the conserved CaMKI/CMK-1 as an essential cell-autonomous regulator for behavioral plasticity to environmental salt in C. elegans.Significance StatementLike other animals, the nematode Caenorhabditis elegans depends on salt for survival and navigates toward high concentrations of this essential mineral. Because salt generates osmotic stress at high concentrations, it also threatens the survival of small terrestrial animals like C. elegans. A growing body of evidence indicates that C. elegans balances these factors through a process called salt aversive learning. We show that this behavior depends on expression of a calcium/calmodulin-dependent kinase, CMK-1, in the ASE salt sensing neurons and that salt-induced calcium signals in the ASE neurons are less sensitive to salt conditioning in animals lacking CMK-1 function. Our study identifies CMK-1 and sensory neurons as key factors in this form of behavioral plasticity.

scholarly journals The heat shock transcription factor HSF-1 protects Caenorhabditis elegans from peroxide stress

2020 ◽  
Author(s):  
Francesco A. Servello ◽  
Javier Apfeld
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Caenorhabditis Elegans ◽  
Heat Shock ◽  
Defense Mechanisms ◽  
Heat Shock Transcription Factor ◽  
Transactivation Domain ◽  
C Elegans ◽  
Multicellular Organisms ◽  
Mild Temperature

AbstractCells induce conserved defense mechanisms that protect them from oxidative stress. How these defenses are regulated in multicellular organisms is incompletely understood. Using the nematode Caenorhabditis elegans, we show that the heat shock transcription factor HSF-1 protects the nematode from the oxidative stress induced by environmental peroxide. In response to a heat shock or a mild temperature increase, HSF-1 protects the nematodes from subsequent oxidative stress in a manner that depends on HSF-1’s transactivation domain. At constant temperature, HSF-1 protects the nematodes from oxidative stress independently of its transactivation domain, likely by inducing the expression of asp-4/cathepsin D and dapk-1/dapk. Thus, two distinct HSF-1-dependent processes protect C. elegans from oxidative stress.

scholarly journals The genes pme-1 and pme-2 encode two poly(ADP-ribose) polymerases in Caenorhabditis elegans

2002 ◽  
Vol 368 (1) ◽  
pp. 263-271 ◽  
Author(s):  
Steve N. GAGNON ◽  
Michael O. HENGARTNER ◽  
Serge DESNOYERS
Keyword(s):  
Caenorhabditis Elegans ◽  
Messenger Rna ◽  
Catalytic Domain ◽  
Post Translational Modification ◽  
Developmentally Regulated ◽  
Splice Leader ◽  
C Elegans ◽  
Zinc Finger Motifs ◽  
Multicellular Organisms ◽  
Parp 1

Poly(ADP-ribose) polymerases (PARPs) are an expanding, well-conserved family of enzymes found in many metazoan species, including plants. The enzyme catalyses poly(ADP-ribosyl)ation, a post-translational modification that is important in DNA repair and programmed cell death. In the present study, we report the finding of an endogenous source of poly(ADP-ribosyl)ation in total extracts of the nematode Caenorhabditis elegans. Two cDNAs encoding highly similar proteins to human PARP-1 (huPARP-1) and huPARP-2 are described, and we propose to name the corresponding enzymes poly(ADP-ribose) metabolism enzyme 1 (PME-1) and PME-2 respectively. PME-1 (108kDa) shares 31% identity with huPARP-1 and has an overall structure similar to other PARP-1 subfamily members. It contains sequences having considerable similarity to zinc-finger motifs I and II, as well as with the catalytic domain of huPARP-1. PME-2 (61kDa) has structural similarities with the catalytic domain of PARPs in general and shares 24% identity with huPARP-2. Recombinant PME-1 and PME-2 display PARP activity, which may partially account for the similar activity found in the worm. A partial duplication of the pme-1 gene with pseudogene-like features was found in the nematode genome. Messenger RNA for pme-1 are 5′-tagged with splice leader 1, whereas those for pme-2 are tagged with splice leader 2, suggesting an operon-like expression for pme-2. The expression pattern of pme-1 and pme-2 is also developmentally regulated. Together, these results show that PARP-1 and −2 are conserved in evolution and must have important functions in multicellular organisms. We propose using C. elegans as a model to understand better the functions of these enzymes.

scholarly journals Distributed rhythm generators underlie Caenorhabditis elegans forward locomotion

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Anthony D Fouad ◽  
Shelly Teng ◽  
Julian R Mark ◽  
Alice Liu ◽  
Pilar Alvarez-Illera ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Motor Neurons ◽  
Animal Behavior ◽  
Rhythm Generation ◽  
Rhythmic Movements ◽  
Neural Oscillators ◽  
Motor Circuit ◽  
C Elegans ◽  
Body Regions ◽  
Forward Locomotion

Coordinated rhythmic movements are ubiquitous in animal behavior. In many organisms, chains of neural oscillators underlie the generation of these rhythms. In C. elegans, locomotor wave generation has been poorly understood; in particular, it is unclear where in the circuit rhythms are generated, and whether there exists more than one such generator. We used optogenetic and ablation experiments to probe the nature of rhythm generation in the locomotor circuit. We found that multiple sections of forward locomotor circuitry are capable of independently generating rhythms. By perturbing different components of the motor circuit, we localize the source of secondary rhythms to cholinergic motor neurons in the midbody. Using rhythmic optogenetic perturbation, we demonstrate bidirectional entrainment of oscillations between different body regions. These results show that, as in many other vertebrates and invertebrates, the C. elegans motor circuit contains multiple oscillators that coordinate activity to generate behavior.

scholarly journals CaMK (CMK-1) and O-GlcNAc transferase (OGT-1) modulate mechanosensory responding and habituation in an interstimulus interval-dependent manner in Caenorhabditis elegans

2017 ◽  
Author(s):  
Evan L. Ardiel ◽  
Troy A. McDiarmid ◽  
Tiffany A. Timbers ◽  
Kirsten C. Y. Lee ◽  
Javad Safaei ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Interstimulus Interval ◽  
Behavioral Plasticity ◽  
Neural Circuit ◽  
Model Organisms ◽  
Dependent Manner ◽  
Mechanical Stimuli ◽  
C Elegans ◽  
Mutant Phenotypes ◽  
Glcnac Transferase

AbstractThe ability to learn is an evolutionarily conserved adaptation that remains incompletely understood. Genetically tractable model organisms facilitate mechanistic explanations of learning that span genetic, neural circuit, and behavioural levels. Many aspects of neural physiology, including processes that underlie learning (e.g. neurotransmitter release and long-lasting changes in synaptic strength), are regulated by brief and local changes in [μm] levels of free intracellular Ca2+. On this scale, changes in [Ca2+] activate many Ca2+-sensors, including the Ca2+/calmodulin-dependent kinases (CaMKs). Here we reveal that the Caenorhabditis elegans ortholog of CaMK1/4, CMK-1, functions in primary sensory neurons to regulate responses to mechanical stimuli and behavioral plasticity, specifically habituation, a conserved form of non-associative learning. The habituation phenotypes of cmk-1 mutants were dependent on interstimulus interval (ISI), such that CMK-1 slows habituation at short ISIs, but promotes it at long ISIs. We predicted potential CaMK phosphorylation targets from catalytic site analysis of the human and C. elegans CaMKs and mutant analysis of these candidates implicated O-linked N-acetylglucosamine (O-GlcNAc) transferase, OGT-1, in mechanosensitivity and learning. Cell specific rescue and knockdown experiments showed that both CMK-1 and OGT-1 function cell autonomously in mechanosensory neurons to modulate learning. Interestingly, despite their similar mutant phenotypes, detailed behavioral analysis of double mutants demonstrated that CMK-1 and OGT-1 act in parallel genetic pathways. Our research identifies CMK-1 and OGT-1 as co-expressed yet independent regulators of mechanosensitivity and learning.

Sign in / Sign up

Export Citation Format

Share Document