scholarly journals A nematode-specific gene underlies bleomycin-response variation in Caenorhabditis elegans

2019 ◽  
Author(s):  
Shannon C. Brady ◽  
Stefan Zdraljevic ◽  
Karol W. Bisaga ◽  
Robyn E. Tanny ◽  
Daniel E. Cook ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Mapping ◽  
Wild Strain ◽  
Model Organism ◽  
Laboratory Strain ◽  
Genomic Region ◽  
Specific Gene ◽  
Chemotherapeutic Drug ◽  
Genetic Determinants ◽  
Response Variation

ABSTRACTBleomycin is a powerful chemotherapeutic drug used to treat a variety of cancers. However, individual patients vary in their responses to bleomycin. The identification of genetic differences that underlie this response variation could improve treatment outcomes by tailoring bleomycin dosages to each patient. We used the model organism Caenorhabditis elegans to identify genetic determinants of bleomycin-response differences by performing linkage mapping on recombinants derived from a cross between the laboratory strain (N2) and a wild strain (CB4856). This approach identified a small genomic region on chromosome V that underlies bleomycin-response variation. Using near-isogenic lines and strains with CRISPR-Cas9 mediated deletions and allele replacements, we discovered that a novel nematode-specific gene (scb-1) is required for bleomycin resistance. Although the mechanism by which this gene causes variation in bleomycin responses is unknown, we suggest that a rare variant present in the CB4856 strain might cause differences in the potential stress-response function of scb-1 between the N2 and CB4856 strains, thereby leading to differences in bleomycin resistance.

scholarly journals The ancestral C. elegans cuticle suppresses rol-1

2020 ◽  
Author(s):  
Luke M. Noble ◽  
Asif Miah ◽  
Taniya Kaur ◽  
Matthew V. Rockman
Keyword(s):  
Genetic Variation ◽  
Caenorhabditis Elegans ◽  
Comparative Genomics ◽  
Linkage Mapping ◽  
Genetic Background ◽  
Gene Editing ◽  
Wild Strain ◽  
Collagen Gene ◽  
Natural Genetic Variation ◽  
C Elegans

ABSTRACTGenetic background commonly modifies the effects of mutations. We discovered that worms mutant for the canonical rol-1 gene, identified by Brenner in 1974, do not roll in the genetic background of the wild strain CB4856. Using linkage mapping, association analysis and gene editing, we determined that N2 carries an insertion in the collagen gene col-182 that acts as a recessive enhancer of rol-1 rolling. From population and comparative genomics, we infer the insertion is derived in N2 and related laboratory lines, likely arising during the domestication of Caenorhabditis elegans, and breaking a conserved protein. The ancestral version of col-182 also modifies the phenotypes of four other classical cuticle mutant alleles, and the effects of natural genetic variation on worm shape and locomotion. These results underscore the importance of genetic background and the serendipity of Brenner’s choice of strain.

scholarly journals The Ancestral Caenorhabditis elegans Cuticle Suppresses rol-1

2020 ◽  
Vol 10 (7) ◽  
pp. 2385-2395 ◽  
Author(s):  
Luke M. Noble ◽  
Asif Miah ◽  
Taniya Kaur ◽  
Matthew V. Rockman
Keyword(s):  
Genetic Variation ◽  
Caenorhabditis Elegans ◽  
Comparative Genomics ◽  
Linkage Mapping ◽  
Genetic Background ◽  
Gene Editing ◽  
Wild Strain ◽  
Collagen Gene ◽  
Natural Genetic Variation ◽  
Link Type

Genetic background commonly modifies the effects of mutations. We discovered that worms mutant for the canonical rol-1 gene, identified by Brenner in 1974, do not roll in the genetic background of the wild strain CB4856. Using linkage mapping, association analysis and gene editing, we determined that N2 carries an insertion in the collagen gene col-182 that acts as a recessive enhancer of rol-1 rolling. From population and comparative genomics, we infer the insertion is derived in N2 and related laboratory lines, likely arising during the domestication of Caenorhabditis elegans, and breaking a conserved protein. The ancestral version of col-182 also modifies the phenotypes of four other classical cuticle mutant alleles, and the effects of natural genetic variation on worm shape and locomotion. These results underscore the importance of genetic background and the serendipity of Brenner’s choice of strain.

scholarly journals Comparative Transcriptomics of heads and tails between Steinernema carpocapsae and Caenorhabditis elegans

2020 ◽  
Author(s):  
Isaryhia Maya Rodriguez ◽  
Lorrayne Serra Clague ◽  
Cassandra Joan McGill ◽  
Bryan Rodriguez ◽  
Ali Mortazavi
Keyword(s):  
Gene Expression ◽  
Caenorhabditis Elegans ◽  
Neuronal Development ◽  
Model Organism ◽  
The Body ◽  
Steinernema Carpocapsae ◽  
Specific Gene ◽  
Body Parts ◽  
C Elegans

AbstractSteinernema nematodes have been widely studied for insect infection and mutualism, but little is known about the patterns of gene expression along the body of these worms or how these compare to the model organism Caenorhabditis elegans. Here we perform the first comparative analysis between the heads and tail regions of Steinernema carpocapsae and C. elegans Infective Juveniles (IJs)/dauers and young adults using single-worm RNA-seq. While we find overall agreement in gene expression there were several sets of genes with substantial differences between the two species. Gene expression in the S. carpocapsae female compared to the C. elegans hermaphrodite heads and tails revealed differences in metabolism, aging, and determination of lifespan. Young adult male heads and tails showed major differences in developmental related processes such as morphogenesis as well as neuronal development and signaling. We also found head- and tail-specific gene expression differences between S. carpocapsae IJs and C. elegans dauers for genes related to growth and development as well as neuronal signaling and activity. This study is one of the first comparative transcriptomic analyses of body parts between distantly related species of nematodes and provides insight into both the highly conserved and genetically distinctive characteristics of both species.

An integrative redescription of Hypsibius dujardini (Doyère, 1840), the nominal taxon for Hypsibioidea (Tardigrada: Eutardigrada)

Zootaxa ◽  
2018 ◽  
Vol 4415 (1) ◽  
pp. 45 ◽  
Author(s):  
PIOTR GĄSIOREK ◽  
DANIEL STEC ◽  
WITOLD MOREK ◽  
ŁUKASZ MICHALCZYK
Keyword(s):  
Dna Sequences ◽  
Evolutionary Biology ◽  
Model Organism ◽  
Laboratory Strain ◽  
Sensu Stricto ◽  
Nominal Species ◽  
28S Rrna ◽  
The Family ◽  
The 19Th Century ◽  
Hypsibius Dujardini

A laboratory strain identified as “Hypsibius dujardini” is one of the best studied tardigrade strains: it is widely used as a model organism in a variety of research projects, ranging from developmental and evolutionary biology through physiology and anatomy to astrobiology. Hypsibius dujardini, originally described from the Île-de-France by Doyère in the first half of the 19th century, is now the nominal species for the superfamily Hypsibioidea. The species was traditionally considered cosmopolitan despite the fact that insufficient, old and sometimes contradictory descriptions and records prevented adequate delineations of similar Hypsibius species. As a consequence, H. dujardini appeared to occur globally, from Norway to Samoa. In this paper, we provide the first integrated taxonomic redescription of H. dujardini. In addition to classic imaging by light microscopy and a comprehensive morphometric dataset, we present scanning electron photomicrographs, and DNA sequences for three nuclear markers (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial marker (COI) that are characterised by various mutation rates. The results of our study reveal that a commercially available strain that is maintained in many laboratories throughout the world, and assumed to represent H. dujardini sensu stricto, represents, in fact, a new species: H. exemplaris sp. nov. Redescribing the nominal taxon for Hypsibiidae, we also redefine the family and amend the definitions of the subfamily Hypsibiinae and the genus Hypsibius. Moreover, we transfer H. arcticus (Murray, 1907) and Hypsibius conifer Mihelčič, 1938 to the genus Ramazzottius since the species exhibit claws and eggs of the Ramazzottius type. Finally, we designate H. fuhrmanni as subjectively invalid because the extremely poor description precludes identifying neotype material. 

Behavioral Effects of Volatile Anesthetics in Caenorhabditis elegans

1996 ◽  
Vol 85 (4) ◽  
pp. 901-912 ◽  
Author(s):  
Michael C. Crowder ◽  
Laynie D. Shebester ◽  
Tim Schedl
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Time Course ◽  
Model Organism ◽  
Volatile Anesthetic ◽  
Volatile Anesthetics ◽  
Effective Concentration ◽  
Forward Genetics ◽  
C Elegans ◽  
Median Effective Concentration

Background The nematode Caenorhabditis elegans offers many advantages as a model organism for studying volatile anesthetic actions. It has a simple, well-understood nervous system; it allows the researcher to do forward genetics; and its genome will soon be completely sequenced. C. elegans is immobilized by volatile anesthetics only at high concentrations and with an unusually slow time course. Here other behavioral dysfunctions are considered as anesthetic endpoints in C. elegans. Methods The potency of halothane for disrupting eight different behaviors was determined by logistic regression of concentration and response data. Other volatile anesthetics were also tested for some behaviors. Established protocols were used for behavioral endpoints that, except for pharyngeal pumping, were set as complete disruption of the behavior. Time courses were measured for rapid behaviors. Recovery from exposure to 1 or 4 vol% halothane was determined for mating, chemotaxis, and gross movement. All experiments were performed at 20 to 22 degrees C. Results The median effective concentration values for halothane inhibition of mating (0.30 vol%-0.21 mM), chemotaxis (0.34 vol%-0.24 mM), and coordinated movement (0.32 vol% - 0.23 mM) were similar to the human minimum alveolar concentration (MAC; 0.21 mM). In contrast, halothane produced immobility with a median effective concentration of 3.65 vol% (2.6 mM). Other behaviors had intermediate sensitivities. Halothane's effects reached steady-state in 10 min for all behaviors tested except immobility, which required 2 h. Recovery was complete after exposure to 1 vol% halothane but was significantly reduced after exposure to immobilizing concentrations. Conclusions Volatile anesthetics selectively disrupt C. elegans behavior. The potency, time course, and recovery characteristics of halothane's effects on three behaviors are similar to its anesthetic properties in vertebrates. The affected nervous system molecules may express structural motifs similar to those on vertebrate anesthetic targets.

Presynaptic targets for acute ethanol sensitivity

2010 ◽  
Vol 38 (1) ◽  
pp. 172-176 ◽  
Author(s):  
Jeff W. Barclay ◽  
Margaret E. Graham ◽  
Mark R. Edwards ◽  
James R. Johnson ◽  
Alan Morgan ◽  
...  
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Alcohol Abuse ◽  
Synaptic Vesicle ◽  
Protein Interactions ◽  
Model Organism ◽  
Acute Exposure ◽  
Ethanol Sensitivity ◽  
Acute Ethanol ◽  
Specific Proteins

Acute exposure to ethanol is known to modulate signalling within the nervous system. Physiologically these effects are both presynaptic and postsynaptic in origin; however, considerably more research has focused primarily on postsynaptic targets. Recent research using the model organism Caenorhabditis elegans has determined a role for specific proteins (Munc18-1 and Rab3) and processes (synaptic vesicle recruitment and fusion) in transducing the presynaptic effects of ethanol. In the present paper, we review these results, identifying the proteins and protein interactions involved in ethanol sensitivity and discuss their links with mammalian studies of alcohol abuse.

scholarly journals Caenorhabditis elegans, a pluricellular model organism to screen new genes involved in mitochondrial genome maintenance

2010 ◽  
Vol 1802 (9) ◽  
pp. 765-773 ◽  
Author(s):  
Matthew Glover Addo ◽  
Raynald Cossard ◽  
Damien Pichard ◽  
Kwasi Obiri-Danso ◽  
Agnès Rötig ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Mitochondrial Genome ◽  
Model Organism ◽  
Genome Maintenance ◽  
New Genes
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