A limited number of Caenorhabditis elegans genes are readily mutable to dominant, temperature-sensitive maternal-effect embryonic lethality.
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.
Mitenko
N L
NL
Department of Medical Biochemistry, The University of Calgary, Alberta, Canada.
Eisner
J R
JR
Swiston
J R
JR
Mains
P E
PE
D000483:Alleles; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics*; D005799:Genes, Dominant; D017238:Genes, Helminth; D005804:Genes, Lethal; D009154:Mutation; D010641:Phenotype; D013696:Temperature