ISOLATION AND GENETIC CHARACTERIZATION OF CELL-LINEAGE MUTANTS OF THE NEMATODE CAENORHABDITIS ELEGANS

Genetics ◽  
1980 ◽  
Vol 96 (2) ◽  
pp. 435-454 ◽  
Author(s):  
H Robert Horvitz ◽  
John E Sulston
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Lineage ◽  
Embryonic Cell ◽  
Null Alleles ◽  
Recessive Mutation ◽  
Incomplete Penetrance ◽  
Nematode Caenorhabditis Elegans ◽  
Cell Lineages ◽  
Cell Divisions ◽  
Recessive Mutations

ABSTRACT Twenty-four mutants that alter the normally invariant post-embryonic cell lineages of the nematode Caenorhabditis elegans have been isolated and genetically characterized. In some of these mutants, cell divisions fail that occur in wild-type animals; in other mutants, cells divide that do not normally do so. The mutants differ in the specificities of their defects, so that it is possible to identify mutations that affect some cell lineages but not others. These mutants define 14 complementation groups, which have been mapped. The abnormal phenotype of most of the cell-lineage mutants results from a single recessive mutation; however, the excessive cell divisions characteristic of one strain, CB1322, require the presence of two unlinked recessive mutations. All 24 cell-lineage mutants display incomplete penetrance and/or variable expressivity. Three of the mutants are suppressed by pleiotropic suppressors believed to be specific for null alleles, suggesting that their phenotypes result from the complete absence of gene activity.

scholarly journals Rules of Nonallelic Noncomplementation at the Synapse in Caenorhabditis elegans

Genetics ◽  
2001 ◽  
Vol 158 (1) ◽  
pp. 209-220 ◽  
Author(s):  
Karen J Yook ◽  
Stephen R Proulx ◽  
Erik M Jorgensen
Keyword(s):  
Caenorhabditis Elegans ◽  
Gene Product ◽  
Genetic Interaction ◽  
Synaptic Proteins ◽  
Null Alleles ◽  
Nematode Caenorhabditis Elegans ◽  
Recessive Mutations ◽  
Genes Encoding ◽  
Physical Interactions ◽  
Encoding Gene

Abstract Nonallelic noncomplementation occurs when recessive mutations in two different loci fail to complement one another, in other words, the double heterozygote exhibits a phenotype. We observed that mutations in the genes encoding the physically interacting synaptic proteins UNC-13 and syntaxin/UNC-64 failed to complement one another in the nematode Caenorhabditis elegans. Noncomplementation was not observed between null alleles of these genes and thus this genetic interaction does not occur with a simple decrease in dosage at the two loci. However, noncomplementation was observed if at least one gene encoded a partially functional gene product. Thus, this genetic interaction requires a poisonous gene product to sensitize the genetic background. Nonallelic noncomplementation was not limited to interacting proteins: Although the strongest effects were observed between loci encoding gene products that bind to one another, interactions were also observed between proteins that do not directly interact but are members of the same complex. We also observed noncomplementation between genes that function at distant points in the same pathway, implying that physical interactions are not required for nonallelic noncomplementation. Finally, we observed that mutations in genes that function in different processes such as neurotransmitter synthesis or synaptic development complement one another. Thus, this genetic interaction is specific for genes acting in the same pathway, that is, for genes acting in synaptic vesicle trafficking.

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.

The embryonic cell lineage of the nematode Caenorhabditis elegans

1983 ◽  
Vol 100 (1) ◽  
pp. 64-119 ◽  
Author(s):  
J.E. Sulston ◽  
E. Schierenberg ◽  
J.G. White ◽  
J.N. Thomson
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Lineage ◽  
Embryonic Cell ◽  
Nematode Caenorhabditis Elegans

scholarly journals Effect of a Neuropeptide Gene on Behavioral States in Caenorhabditis elegans Egg-Laying

Genetics ◽  
2000 ◽  
Vol 154 (3) ◽  
pp. 1181-1192 ◽  
Author(s):  
Laura E Waggoner ◽  
Laura Anne Hardaker ◽  
Steven Golik ◽  
William R Schafer
Keyword(s):  
Caenorhabditis Elegans ◽  
Active Phase ◽  
Egg Laying ◽  
Sensory Cues ◽  
Nematode Caenorhabditis Elegans ◽  
Inactive State ◽  
Recessive Mutations ◽  
Inactive Phase ◽  
Behavioral States ◽  
Stimulation Of

Abstract Egg-laying behavior in the nematode Caenorhabditis elegans involves fluctuation between alternative behavioral states: an inactive state, during which eggs are retained in the uterus, and an active state, during which eggs are laid in bursts. We have found that the flp-1 gene, which encodes a group of structurally related neuropeptides, functions specifically to promote the switch from the inactive to the active egg-laying state. Recessive mutations in flp-1 caused a significant increase in the duration of the inactive phase, yet egg-laying within the active phase was normal. This pattern resembled that previously observed in mutants defective in the biosynthesis of serotonin, a neuromodulator implicated in induction of the active phase. Although flp-1 mutants were sensitive to stimulation of egg-laying by serotonin, the magnitude of their serotonin response was abnormally low. Thus, the flp-1-encoded peptides and serotonin function most likely function in concert to facilitate the onset of the active egg-laying phase. Interestingly, we observed that flp-1 is necessary for animals to down-regulate their rate of egg-laying in the absence of food. Because flp-1 is known to be expressed in interneurons that are postsynaptic to a variety of chemosensory cells, the FLP-1 peptides may function to regulate the activity of the egg-laying circuitry in response to sensory cues.

Major sex-determining genes and the control of sexual dimorphism in Caenorhabditis elegans

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 625-637 ◽  
Author(s):  
Jonathan Hodgkin ◽  
Andrew D. Chisholm ◽  
Michael M. Shen
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
X Chromosome ◽  
Germ Line ◽  
Cell Lineage ◽  
Regulatory Genes ◽  
Nematode Caenorhabditis Elegans ◽  
X Chromosomes ◽  
The Many ◽  
Lineage Analysis

Sex determination in Caenorhabditis elegans involves a cascade of major regulatory genes connecting the primary sex determining signal, X chromosome dosage, to key switch genes, which in turn direct development along either male or female pathways. Animals with one X chromosome (XO) are male, while animals with two X chromosomes (XX) are hermaphrodite: hermaphrodite development occurs because the action of the regulatory genes is modified in the germ line so that both sperm and oocytes are made inside a completely female soma. The regulatory genes are being examined by both genetic and molecular means. We discuss how these major genes, in particular the last switch gene in the cascade, tra-1, might regulate the many different sex-specific events that occur during the development of the hermaphrodite and of the male.Key words: nematode, Caenorhabditis elegans, sex determination, sexual differentiation, cell lineage analysis.

The Caenorhabditis elegans gene lin-44 controls the polarity of asymmetric cell divisions

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1035-1047 ◽  
Author(s):  
M.A. Herman ◽  
H.R. Horvitz
Keyword(s):  
Caenorhabditis Elegans ◽  
The Body ◽  
Body Axis ◽  
Nematode Caenorhabditis Elegans ◽  
Asymmetric Cell Divisions ◽  
Cell Divisions ◽  
Sister Cells

The generation and orientation of cellular and organismic polarity are fundamental aspects of development. Mutations in the gene lin-44 of the nematode Caenorhabditis elegans reverse both the relative positions of specific sister cells and the apparent polarities of these cells. Thus, lin-44 mutants appear to generate polar cells but to misorient these cells along the body axis of the animal. We postulate that lin-44 acts to specify the orientation of polar cells.

PES-1 is expressed during early embryogenesis in Caenorhabditis elegans and has homology to the fork head family of transcription factors

Development ◽  
1994 ◽  
Vol 120 (3) ◽  
pp. 505-514 ◽  
Author(s):  
I.A. Hope
Keyword(s):  
Transcription Factors ◽  
Caenorhabditis Elegans ◽  
Cell Lineage ◽  
Embryonic Cell ◽  
Early Embryogenesis ◽  
C Elegans ◽  
Promoter Trapping ◽  
Fork Head ◽  
Initiation Of Transcription ◽  
Beta Galactosidase

Promoter trapping has identified a gene, pes-1, which is expressed during C. elegans embryogenesis. The beta-galactosidase expression pattern, directed by the pes-1/lacZ fusion through which this gene was cloned, has been determined precisely in terms of the embryonic cell lineage and has three components. One component is in a subset of cells of the AB founder cell lineage during early embryogenesis, suggesting pes-1 may be regulated both by cell autonomous determinants and by intercellular signals. Analysis of cDNA suggests pes-1 has two sites for initiation of transcription and the two transcripts would encode related but distinct proteins. The predicted PES-1 proteins have homology to the fork head family of transcription factors and therefore may have important regulatory roles in early embryogenesis.

scholarly journals Cell lineages of the embryo of the nematode Caenorhabditis elegans.

1978 ◽  
Vol 75 (1) ◽  
pp. 376-380 ◽  
Author(s):  
U. Deppe ◽  
E. Schierenberg ◽  
T. Cole ◽  
C. Krieg ◽  
D. Schmitt ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Nematode Caenorhabditis Elegans ◽  
Cell Lineages
Sign in / Sign up

Export Citation Format

Share Document