scholarly journals A Canal-Associated Neuron cAMP signalling pathway that regulates C. elegans larval development

2019 ◽  
Author(s):  
Jason Chien ◽  
Fred W. Wolf ◽  
Sarah Grosche ◽  
Nebeyu Yosef ◽  
Gian Garriga ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Cyclic Amp ◽  
Adenylyl Cyclase ◽  
Larval Development ◽  
Laser Microsurgery ◽  
Gain Of Function ◽  
Specific Expression ◽  
C Elegans ◽  
Similar Phenotype ◽  
Pka Pathway

ABSTRACTCaenorhabditis elegans larval development requires the function of the two Canal-Associated Neurons (CANs): killing the CANs by laser microsurgery or disrupting their development by mutating the gene ceh-10 results in early larval arrest. How these cells promote larval development, however, remains a mystery. In screens for mutations that bypass CAN function, we identified the gene kin-29, which encodes a member of the Salt-Inducible Kinase (SIK) family and a component of a conserved pathway that regulates various C. elegans phenotypes. Like kin-29 loss, gain-of-function mutations in genes that may act upstream of kin-29 or growth in cyclic-AMP analogs bypassed ceh-10 larval arrest, suggesting that a conserved adenylyl cyclase/PKA pathway inhibits KIN-29 to promote larval development and that loss of CAN function results in dysregulation of KIN-29 and larval arrest. The adenylyl cyclase ACY-2 mediates CAN-dependent larval development: acy-2 mutant larvae arrested development with a similar phenotype to ceh-10 mutants, and the arrest phenotype was suppressed by mutations in kin-29. ACY-2 is predominantly expressed in the CANs, and we provide evidence that the acy-2 functions in the CANs to promote larval development. By contrast, cell-specific expression experiments suggest that kin-29 acts in both the hypodermis and neurons, but not in the CANs. Based on our findings, we propose that cAMP produced by ACY-2 in the CANs acts in neighboring neurons and hypodermal cells where it activates PKA and inhibits KIN-29 to promote larval development. We discuss how this conserved pathway could be partitioned between two cells.

scholarly journals The Enigmatic Canal-Associated Neurons Regulate Caenorhabditis elegans Larval Development Through a cAMP Signaling Pathway

Genetics ◽  
2019 ◽  
Vol 213 (4) ◽  
pp. 1465-1478
Author(s):  
Jason Chien ◽  
Fred W. Wolf ◽  
Sarah Grosche ◽  
Nebeyu Yosef ◽  
Gian Garriga ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Adenylyl Cyclase ◽  
Larval Development ◽  
Target Cells ◽  
Specific Expression ◽  
C Elegans ◽  
Link Type ◽  
Similar Phenotype ◽  
Link Loss ◽  
Pka Pathway

Caenorhabditis elegans larval development requires the function of the two Canal-Associated Neurons (CANs): killing the CANs by laser microsurgery or disrupting their development by mutating the gene ceh-10 results in early larval arrest. How these cells promote larval development, however, remains a mystery. In screens for mutations that bypass CAN function, we identified the gene kin-29, which encodes a member of the Salt-Inducible Kinase (SIK) family and a component of a conserved pathway that regulates various C. elegans phenotypes. Like kin-29 loss, gain-of-function mutations in genes that may act upstream of kin-29 or growth in cyclic-AMP analogs bypassed ceh-10 larval arrest, suggesting that a conserved adenylyl cyclase/PKA pathway inhibits KIN-29 to promote larval development, and that loss of CAN function results in dysregulation of KIN-29 and larval arrest. The adenylyl cyclase ACY-2 mediates CAN-dependent larval development: acy-2 mutant larvae arrested development with a similar phenotype to ceh-10 mutants, and the arrest phenotype was suppressed by mutations in kin-29. ACY-2 is expressed predominantly in the CANs, and we provide evidence that the acy-2 functions in the CANs to promote larval development. By contrast, cell-specific expression experiments suggest that kin-29 acts in both the hypodermis and neurons, but not in the CANs. Based on our findings, we propose two models for how ACY-2 activity in the CANs regulates KIN-29 in target cells.

Effect of structurally related flavonoids from Zuccagnia punctata Cav. on Caenorhabditis elegans

2014 ◽  
Vol 60 (1) ◽  
Author(s):  
Romina E. D’Almeida ◽  
María R. Alberto ◽  
Phillip Morgan ◽  
Margaret Sedensky ◽  
María I. Isla
Keyword(s):  
Caenorhabditis Elegans ◽  
Larval Development ◽  
Free Living ◽  
Egg Hatching ◽  
C Elegans ◽  
Therapeutic Drugs ◽  
Aerial Parts ◽  
Free Living Nematode ◽  
Development Processes ◽  
Anthelmintic Effect

AbstractZuccagnia punctata Cav. (Fabaceae), commonly called jarilla macho or pus-pus, is being used in traditional medicine as an antiseptic, anti-inflammatory and to relieve muscle and bone pain. The aim of this work was to study the anthelmintic effects of three structurally related flavonoids present in aerial parts of Z. punctata Cav. The biological activity of the flavonoids 7-hydroxyflavanone (HF), 3,7-dihydroxyflavone (DHF) and 2´,4´-dihydroxychalcone (DHC) was examined in the free-living nematode Caenorhabditis elegans. Our results showed that among the assayed flavonoids, only DHC showed an anthelmintic effect and alteration of egg hatching and larval development processes in C. elegans. DHC was able to kill 50% of adult nematodes at a concentration of 17 μg/mL. The effect on larval development was observed after 48 h in the presence of 25 and 50 μg/mL DHC, where 33.4 and 73.4% of nematodes remained in the L3 stage or younger. New therapeutic drugs with good efficacy against drug-resistant nematodes are urgently needed. Therefore, DHC, a natural compound present in Z. punctata, is proposed as a potential anthelmintic drug.

scholarly journals An economical and highly adaptable optogenetics system for individual and population-level manipulation of Caenorhabditis elegans

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
M. Koopman ◽  
L. Janssen ◽  
E. A. A. Nollen
Keyword(s):  
Caenorhabditis Elegans ◽  
Light Stimulus ◽  
Cholinergic Neurons ◽  
Model Organisms ◽  
Parameter Study ◽  
Multiple Model ◽  
Excitable Cells ◽  
Specific Expression ◽  
C Elegans ◽  
Age Related

Abstract Background Optogenetics allows the experimental manipulation of excitable cells by a light stimulus without the need for technically challenging and invasive procedures. The high degree of spatial, temporal, and intensity control that can be achieved with a light stimulus, combined with cell type-specific expression of light-sensitive ion channels, enables highly specific and precise stimulation of excitable cells. Optogenetic tools have therefore revolutionized the study of neuronal circuits in a number of models, including Caenorhabditis elegans. Despite the existence of several optogenetic systems that allow spatial and temporal photoactivation of light-sensitive actuators in C. elegans, their high costs and low flexibility have limited wide access to optogenetics. Here, we developed an inexpensive, easy-to-build, modular, and adjustable optogenetics device for use on different microscopes and worm trackers, which we called the OptoArm. Results The OptoArm allows for single- and multiple-worm illumination and is adaptable in terms of light intensity, lighting profiles, and light color. We demonstrate OptoArm’s power in a population-based multi-parameter study on the contributions of motor circuit cells to age-related motility decline. We found that individual components of the neuromuscular system display different rates of age-dependent deterioration. The functional decline of cholinergic neurons mirrors motor decline, while GABAergic neurons and muscle cells are relatively age-resilient, suggesting that rate-limiting cells exist and determine neuronal circuit ageing. Conclusion We have assembled an economical, reliable, and highly adaptable optogenetics system which can be deployed to address diverse biological questions. We provide a detailed description of the construction as well as technical and biological validation of our set-up. Importantly, use of the OptoArm is not limited to C. elegans and may benefit studies in multiple model organisms, making optogenetics more accessible to the broader research community.

scholarly journals Caenorhabditis elegans FOS-1 and JUN-1 Regulateplc-1Expression in the Spermatheca to Control Ovulation

2009 ◽  
Vol 20 (17) ◽  
pp. 3888-3895 ◽  
Author(s):  
Susan M. Hiatt ◽  
Holli M. Duren ◽  
Y. John Shyu ◽  
Ronald E. Ellis ◽  
Naoki Hisamoto ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Chromatin Remodeling ◽  
Genetic Interactions ◽  
Inositol Triphosphate ◽  
Activator Protein 1 ◽  
Specific Expression ◽  
Vulval Development ◽  
C Elegans ◽  
Physiological Processes ◽  
Rate Limiting

Fos and Jun are components of activator protein-1 (AP-1) and play crucial roles in the regulation of many cellular, developmental, and physiological processes. Caenorhabditis elegans fos-1 has been shown to act in uterine and vulval development. Here, we provide evidence that C. elegans fos-1 and jun-1 control ovulation, a tightly regulated rhythmic program in animals. Knockdown of fos-1 or jun-1 blocks dilation of the distal spermathecal valve, a critical step for the entry of mature oocytes into the spermatheca for fertilization. Furthermore, fos-1 and jun-1 regulate the spermathecal-specific expression of plc-1, a gene that encodes a phospholipase C (PLC) isozyme that is rate-limiting for inositol triphosphate production and ovulation, and overexpression of PLC-1 rescues the ovulation defect in fos-1(RNAi) worms. Unlike fos-1, regulation of ovulation by jun-1 requires genetic interactions with eri-1 and lin-15B, which are involved in the RNA interference pathway and chromatin remodeling, respectively. At least two isoforms of jun-1 are coexpressed with fos-1b in the spermatheca, and different AP-1 dimers formed between these isoforms have distinct effects on the activation of a reporter gene. These findings uncover a novel role for FOS-1 and JUN-1 in the reproductive system and establish C. elegans as a model for studying AP-1 dimerization.

A Limited Number of Caenorhabditis elegans Genes Are Readily Mutable to Dominant, Temperature-Sensitive Maternal-Effect Embryonic Lethality

Genetics ◽  
1997 ◽  
Vol 147 (4) ◽  
pp. 1665-1674 ◽  
Author(s):  
Nancy L Mitenko ◽  
James R Eisner ◽  
John R Swiston ◽  
Paul E Mains
Keyword(s):  
Caenorhabditis Elegans ◽  
Maternal Effect ◽  
Temperature Sensitive ◽  
Loss Of Function ◽  
Gain Of Function ◽  
C Elegans ◽  
Lethal Mutations ◽  
Embryonic Lethal ◽  
Embryonic Lethal Mutations ◽  
Dominant Temperature Sensitive

Abstract Dominant gain-of-function mutations can give unique insights into the study of gene function. In addition, gain-of-function mutations, unlike loss-of-function alleles, are not biased against the identification of genetically redundant loci. To identify novel genetic functions active during Caenorhabditis elegans embryogenesis, we have collected a set of dominant temperature-sensitive maternal-effect embryonic lethal mutations. In a previous screen, we isolated eight such mutations, distributed among six genes. In the present study, we describe eight new dominant mutations that identify only three additional genes, yielding a total of 16 dominant mutations found in nine genes. Therefore, it appears that a limited number of C. elegans genes mutate to this phenotype at appreciable frequencies. Five of the genes that we identified by dominant mutations have loss-of-function alleles. Two of these genes may lack loss-of-function phenotypes, indicating that they are nonessential and so may represent redundant loci. Loss-of-function mutations of three other genes are associated with recessive lethality, indicating nonredundancy.

scholarly journals A Gain-of-function Mutation in Adenylate Cyclase Confers Isoflurane Resistance in Caenorhabditis elegans 

2011 ◽  
Vol 115 (6) ◽  
pp. 1162-1171 ◽  
Author(s):  
Owais Saifee ◽  
Laura B. Metz ◽  
Michael L. Nonet ◽  
C. Michael Crowder
Keyword(s):  
Caenorhabditis Elegans ◽  
Adenylate Cyclase ◽  
Neurotransmitter Release ◽  
Acetylcholinesterase Inhibitor ◽  
Volatile Anesthetic ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
General Anesthetics ◽  
Gain Of Function ◽  
C Elegans

Background Volatile general anesthetics inhibit neurotransmitter release by a mechanism not fully understood. Genetic evidence in Caenorhabditis elegans has shown that a major mechanism of action of volatile anesthetics acting at clinical concentrations in this animal is presynaptic inhibition of neurotransmission. To define additional components of this presynaptic volatile anesthetic mechanism, C. elegans mutants isolated as phenotypic suppressors of a mutation in syntaxin, an essential component of the neurotransmitter release machinery, were screened for anesthetic sensitivity phenotypes. Methods Sensitivity to isoflurane concentrations was measured in locomotion assays on adult C. elegans. Sensitivity to the acetylcholinesterase inhibitor aldicarb was used as an assay for the global level of C. elegans acetylcholine release. Comparisons of isoflurane sensitivity (measured by the EC₅₀) were made by simultaneous curve-fitting and F test. Results Among the syntaxin suppressor mutants, js127 was the most isoflurane resistant, with an EC₅₀ more than 3-fold that of wild type. Genetic mapping, sequencing, and transformation phenocopy showed that js127 was an allele of acy-1, which encodes an adenylate cyclase expressed throughout the C. elegans nervous system and in muscle. js127 behaved as a gain-of-function mutation in acy-1 and had increased concentrations of cyclic adenosine monophosphate. Testing of single and double mutants along with selective tissue expression of the js127 mutation revealed that acy-1 acts in neurons within a Gαs-PKA-UNC-13-dependent pathway to regulate behavior and isoflurane sensitivity. Conclusions Activation of neuronal adenylate cyclase antagonizes isoflurane inhibition of locomotion in C. elegans.

scholarly journals A novel dominant transformer allele of the sex-determining gene her-1 of Caenorhabditis elegans.

Genetics ◽  
1988 ◽  
Vol 120 (1) ◽  
pp. 145-157
Author(s):  
C Trent ◽  
W B Wood ◽  
H R Horvitz
Keyword(s):  
Caenorhabditis Elegans ◽  
Sexual Identity ◽  
Temperature Sensitive ◽  
Dominant Allele ◽  
Loss Of Function ◽  
Gain Of Function ◽  
C Elegans

Abstract We have characterized a novel dominant allele of the sex-determining gene her-1 of Caenorhabditis elegans. This allele, called n695, results in the incomplete transformation of XX animals into phenotypic males. Previously characterized recessive her-1 alleles transform XO animals into phenotypic hermaphrodites. We have identified five new recessive her-1 mutations as intragenic suppressors of n695. Three of these suppressors are weak, temperature-sensitive alleles. We show that the recessive her-1 mutations are loss-of-function alleles, and that the her-1(n695) mutation results in a gain-of-function at the her-1 locus. The existence of dominant and recessive alleles that cause opposite phenotypic transformations demonstrates that the her-1 gene acts to control sexual identity in C. elegans.

scholarly journals In vivo mapping of tissue- and subcellular-specific proteomes in Caenorhabditis elegans

2016 ◽  
Author(s):  
Aaron W. Reinke ◽  
Raymond Mak ◽  
Emily R. Troemel ◽  
Eric J. Bennett
Keyword(s):  
Caenorhabditis Elegans ◽  
Model Organism ◽  
Specific Expression ◽  
Live Animal ◽  
C Elegans ◽  
Cytoplasmic Proteins ◽  
Specific Localization ◽  
Multicellular Organisms ◽  
Subcellular Resolution

AbstractMulticellular organisms are composed of tissues that have distinct functions requiring specialized proteomes. To define the proteome of a live animal with tissue and subcellular resolution, we adapted a localized proteomics technology for use in the multicellular model organism Caenorhabditis elegans. This approach couples tissue- and location-specific expression of the enzyme ascorbate peroxidase (APX), which facilitates proximity-based protein labeling in vivo, and quantitative proteomics to identify tissue- and subcellular-restricted proteomes. We identified and localized over 3000 proteins from strains of C. elegans expressing APX in either the nucleus or cytoplasm of the intestine, epidermis, body wall muscle, or pharyngeal muscle. We also identified several hundred proteins that were specifically localized to one of the four tissues analyzed or specifically localized to the cytoplasm or the nucleus. This approach resulted in the identification of both previously characterized and unknown nuclear and cytoplasmic proteins. Further, we confirmed the tissue- and subcellular-specific localization of a subset of identified proteins using GFP-tagging and fluorescence microscopy, validating our in vivo proximity-based proteomics technique. Together, these results demonstrate a new approach that enables the tissue- and subcellular-specific identification and quantification of proteins within a live animal.

scholarly journals cis regulatory requirements for hypodermal cell-specific expression of the Caenorhabditis elegans cuticle collagen gene dpy-7.

1997 ◽  
Vol 17 (4) ◽  
pp. 2301-2311 ◽  
Author(s):  
J S Gilleard ◽  
J D Barry ◽  
I L Johnstone
Keyword(s):  
Caenorhabditis Elegans ◽  
Reporter Gene ◽  
Collagen Gene ◽  
Promoter Element ◽  
Regulatory Requirements ◽  
Specific Expression ◽  
Tissue Specific ◽  
C Elegans ◽  
Hypodermal Cell ◽  
Tissue Specific Promoter

The Caenorhabditis elegans cuticle collagens are encoded by a multigene family of between 50 and 100 members and are the major component of the nematode cuticular exoskeleton. They are synthesized in the hypodermis prior to secretion and incorporation into the cuticle and exhibit complex patterns of spatial and temporal expression. We have investigated the cis regulatory requirements for tissue- and stage-specific expression of the cuticle collagen gene dpy-7 and have identified a compact regulatory element which is sufficient to specify hypodermal cell reporter gene expression. This element appears to be a true tissue-specific promoter element, since it encompasses the dpy-7 transcription initiation sites and functions in an orientation-dependent manner. We have also shown, by interspecies transformation experiments, that the dpy-7 cis regulatory elements are functionally conserved between C. elegans and C. briggsae, and comparative sequence analysis supports the importance of the regulatory sequence that we have identified by reporter gene analysis. All of our data suggest that the spatial expression of the dpy-7 cuticle collagen gene is established essentially by a small tissue-specific promoter element and does not require upstream activator or repressor elements. In addition, we have found the DPY-7 polypeptide is very highly conserved between the two species and that the C. briggsae polypeptide can function appropriately within the C. elegans cuticle. This finding suggests a remarkably high level of conservation of individual cuticle components, and their interactions, between these two nematode species.

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