Viable maternal-effect mutations that affect the development of the nematode Caenorhabditis elegans.

Genetics ◽  
1995 ◽  
Vol 141 (4) ◽  
pp. 1351-1364 ◽  
Author(s):  
S Hekimi ◽  
P Boutis ◽  
B Lakowski
Keyword(s):  
Quantitative Analysis ◽  
Caenorhabditis Elegans ◽  
Maternal Effect ◽  
Genetic Screen ◽  
Phenotypic Characterization ◽  
Nematode Caenorhabditis Elegans ◽  
Critical Function ◽  
Complementation Groups

Abstract We carried out a genetic screen for viable maternal-effect mutants to identify genes with a critical function relatively early in development. This type of mutation would not have been identified readily in previous screens for viable mutants and therefore could define previously unidentified genes. We screened 30,000 genomes and identified 41 mutations falling into 24 complementation groups. We genetically mapped these 24 loci; only two of them appear to correspond to previously identified genes. We present a partial phenotypic characterization of the mutants and a quantitative analysis of the degree to which they can be maternally or zygotically rescued.

scholarly journals Identification of grandchildless loci whose products are required for normal germ-line development in the nematode Caenorhabditis elegans.

Genetics ◽  
1991 ◽  
Vol 129 (4) ◽  
pp. 1061-1072 ◽  
Author(s):  
E E Capowski ◽  
P Martin ◽  
C Garvin ◽  
S Strome
Keyword(s):  
Drosophila Melanogaster ◽  
Caenorhabditis Elegans ◽  
Germ Cells ◽  
Structural Integrity ◽  
Germ Line ◽  
Phenotypic Characterization ◽  
Nematode Caenorhabditis Elegans ◽  
Homozygous Mutant ◽  
Germ Granules

Abstract To identify genes that encode maternal components required for development of the germ line in the nematode Caenorhabditis elegans, we have screened for mutations that confer a maternal-effect sterile or "grandchildless" phenotype: homozygous mutant hermaphrodites produced by heterozygous mothers are themselves fertile, but produce sterile progeny. Our screens have identified six loci, defined by 21 mutations. This paper presents genetic and phenotypic characterization of four of the loci. The majority of mutations, those in mes-2, mes-3 and mes-4, affect postembryonic germ-line development; the progeny of mutant mothers undergo apparently normal embryogenesis but develop into agametic adults with 10-1000-fold reductions in number of germ cells. In contrast, mutations in mes-1 cause defects in cytoplasmic partitioning during embryogenesis, and the resulting larvae lack germ-line progenitor cells. Mutations in all of the mes loci primarily affect the germ line, and none disrupt the structural integrity of germ granules. This is in contrast to grandchildless mutations in Drosophila melanogaster, all of which disrupt germ granules and affect abdominal as well as germ-line development.

scholarly journals Cloning and biochemical characterization of the cyclophilin homologues from the free-living nematode Caenorhabditis elegans

1996 ◽  
Vol 317 (1) ◽  
pp. 179-185 ◽  
Author(s):  
Antony P. PAGE ◽  
Kenneth MacNIVEN ◽  
Michael O. HENGARTNER
Keyword(s):  
Signal Transduction ◽  
Protein Folding ◽  
Caenorhabditis Elegans ◽  
Biochemical Characterization ◽  
Single Species ◽  
Immunosuppressive Agent ◽  
Specific Substrate ◽  
Nematode Caenorhabditis Elegans ◽  
Isomerase Activity

Cyclosporin A (CsA) is the most widely used immunosuppressive agent, whose properties are exerted via an interaction with cyclophilin, resulting in down-regulation of signal-transduction events in the T-cell. Cyclophilin is identical with peptidylprolyl cis–trans isomerase (PPI; EC 5.2.1.8), an enzyme which catalyses the isomerization between the two proline conformations in proteins, thereby acting as a catalyst in protein-folding events. Several reports indicate that CsA has potent anti-parasitic activity, effective against both protozoan and helminth species. In order to understand the various biological roles that cyclophilins play we have initiated a study of these proteins in the genetically tractable nematode Caenorhabditis elegans. Here we describe the cloning and characterization of 11 cyclophilin genes (cyp-1 to -11) derived from this nematode; this is currently the greatest number of isoforms described in a single species. Southern blotting and physical mapping indicated that these genes are dispersed throughout the nematode genome. A high degree of conservation exists between several isoforms, which also share characteristics with the ubiquitous isoforms previously described. The remaining isoforms are divergent, having altered CsA-binding domains and additional non-cyclophilin domains, which may impart compartmental specificity. Ten of these isoforms have been expressed in Escherichia coli, and the resultant fusion proteins have been examined biochemically for PPI activity, which they all possess. Isomerase activity is highest in the conserved and lowest in divergent isoforms, perhaps indicating a more specific substrate for the latter. Analysis of the C. elegans cyp genes will provide answers as to the roles played by cyclophilins in protein folding and signal transduction.

scholarly journals Isolatio and characterization of metallothionein from nematode(Caenorhabditis elegans)

Eisei kagaku ◽  
1986 ◽  
Vol 32 (1) ◽  
pp. 22-27 ◽  
Author(s):  
KOHJI MARUYAMA ◽  
RITSUKO HORI ◽  
TSUTOMU NISHIHARA ◽  
MASAOMI KONDO
Keyword(s):  
Caenorhabditis Elegans ◽  
Nematode Caenorhabditis Elegans

Parental effects and phenotypic characterization of mutations that affect early development in Caenorhabditis elegans

1980 ◽  
Vol 74 (2) ◽  
pp. 446-469 ◽  
Author(s):  
William B. Wood ◽  
Ralph Hecht ◽  
Stephen Carr ◽  
Rebecca Vanderslice ◽  
Nurit Wolf ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Early Development ◽  
Phenotypic Characterization ◽  
Parental Effects

scholarly journals IDENTIFICATION AND CHARACTERIZATION OF 22 GENES THAT AFFECT THE VULVAL CELL LINEAGES OF THE NEMATODE CAENORHABDITIS ELEGANS

Genetics ◽  
1985 ◽  
Vol 110 (1) ◽  
pp. 17-72
Author(s):  
Edwin L Ferguson ◽  
H Robert Horvitz
Keyword(s):  
Caenorhabditis Elegans ◽  
Gene Function ◽  
Ventral Side ◽  
Recessive Mutation ◽  
Partial Reduction ◽  
Nematode Caenorhabditis Elegans ◽  
Multiple Alleles ◽  
Cell Lineages ◽  
Identification And Characterization

ABSTRACT Ninety-five mutants of the nematode Caenorhabditis elegans altered in the cell lineages of the vulva have been isolated on the basis of their displaying one of two phenotypes, Vulvaless or Multivulva. In Vulvaless mutants, which define 12 genes, no vulva is present. In Multivulva mutants, which define ten genes, one or more supernumerary vulva-like protrusions are located along the ventral side of the animal. A single recessive mutation is responsible for the phenotypes of most, but not all, of these strains. Fifteen of these 22 genes are represented by multiple alleles. We have shown by a variety of genetic criteria that mutations that result in a Vulvaless or Multivulva phenotype in six of the 22 genes most likely eliminate gene function. In addition, Vulvaless or Multivulva mutations in seven of the other genes most likely result in a partial reduction of gene function; the absence of the activity of any of these genes probably results in lethality or sterility. Our results suggest that we may have identified most, or all, genes of these two classes.

scholarly journals A Genetic Screen to Identify New Molecular Players Involved in Photoprotection qH in Arabidopsis thaliana

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1565
Author(s):  
Pierrick Bru ◽  
Sanchali Nanda ◽  
Alizée Malnoë
Keyword(s):  
Arabidopsis Thaliana ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Genetic Screen ◽  
Phenotypic Characterization ◽  
Photochemical Quenching ◽  
Transcriptional Level ◽  
Whole Genome ◽  
Non Photochemical Quenching

Photosynthesis is a biological process which converts light energy into chemical energy that is used in the Calvin–Benson cycle to produce organic compounds. An excess of light can induce damage to the photosynthetic machinery. Therefore, plants have evolved photoprotective mechanisms such as non-photochemical quenching (NPQ). To focus molecular insights on slowly relaxing NPQ processes in Arabidopsis thaliana, previously, a qE-deficient line—the PsbS mutant—was mutagenized and a mutant with high and slowly relaxing NPQ was isolated. The mutated gene was named suppressor of quenching 1, or SOQ1, to describe its function. Indeed, when present, SOQ1 negatively regulates or suppresses a form of antenna NPQ that is slow to relax and is photoprotective. We have now termed this component qH and identified the plastid lipocalin, LCNP, as the effector for this energy dissipation mode to occur. Recently, we found that the relaxation of qH1, ROQH1, protein is required to turn off qH. The aim of this study is to identify new molecular players involved in photoprotection qH by a whole genome sequencing approach of chemically mutagenized Arabidopsis thaliana. We conducted an EMS-mutagenesis on the soq1 npq4 double mutant and used chlorophyll fluorescence imaging to screen for suppressors and enhancers of qH. Out of 22,000 mutagenized plants screened, the molecular players cited above were found using a mapping-by-sequencing approach. Here, we describe the phenotypic characterization of the other mutants isolated from this genetic screen and an additional 8000 plants screened. We have classified them in several classes based on their fluorescence parameters, NPQ kinetics, and pigment content. A high-throughput whole genome sequencing approach on 65 mutants will identify the causal mutations thanks to allelic mutations from having reached saturation of the genetic screen. The candidate genes could be involved in the formation or maintenance of quenching sites for qH, in the regulation of qH at the transcriptional level, or be part of the quenching site itself.

scholarly journals Characterization of N-Acyl Phosphatidylethanolamine-Specific Phospholipase-D Isoforms in the Nematode Caenorhabditis elegans

PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e113007 ◽  
Author(s):  
Neale Harrison ◽  
Museer A. Lone ◽  
Tiffany K. Kaul ◽  
Pedro Reis Rodrigues ◽  
Ifedayo Victor Ogungbe ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Phospholipase D ◽  
Nematode Caenorhabditis Elegans

scholarly journals Molecular basis of loss-of-function mutations in the glp-1 gene of Caenorhabditis elegans.

1992 ◽  
Vol 3 (11) ◽  
pp. 1199-1213 ◽  
Author(s):  
V Kodoyianni ◽  
E M Maine ◽  
J Kimble
Keyword(s):  
Caenorhabditis Elegans ◽  
Growth Factor ◽  
Molecular Basis ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Nematode Caenorhabditis Elegans ◽  
Nonsense Mutations ◽  
Epidermal Growth ◽  
Repeated Motifs

The glp-1 gene encodes a membrane protein required for inductive cell interactions during development of the nematode Caenorhabditis elegans. Here we report the molecular characterization of 15 loss-of-function (lf) mutations of glp-1. Two nonsense mutations appear to eliminate glp-1 activity; both truncate the glp-1 protein in its extracellular domain and have a strong loss-of-function phenotype. Twelve missense mutations and one in-frame deletion map to sites within the repeated motifs of the glp-1 protein (10 epidermal growth factor [EGF]-like and 3 LNG repeats extracellularly and 6 cdc10/SWI6, or ankyrin, repeats intracellularly). We find that all three types of repeated motifs are critical to glp-1 function, and two individual EGF-like repeats may have distinct functions. Intriguingly, all four missense mutations in one phenotypic class map to the N-terminal EGF-like repeats and all six missense mutations in a second phenotypic class reside in the intracellular cdc10/SWI6 repeats. These two clusters of mutations may identify functional domains within the glp-1 protein.

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