title: The lin-12 locus specifies cell fates in Caenorhabditis elegans.
abstract: We describe two classes of mutations in the lin-12 locus of the nematode Caenorhabditis elegans. Ten semidominant mutations (lin-12[d]) appear to elevate the level of lin-12 activity. Thirty-two recessive alleles (lin-12[0]), including two amber mutations, appear to eliminate gene activity. The lin-12(d) and lin-12(0) mutations result in reciprocal homeotic transformations in the fates of defined cells in several different tissues. Gene dosage studies suggest that a high level of lin-12 activity specifies one cell fate and a low level specifies an alternative fate. Temperature-shift experiments indicate that lin-12 acts at the time cell fate is determined in wild type. We propose that lin-12 functions as a binary switch to control decisions between alternative cell fates during C. elegans development.
mesh_terms: D000483:Alleles; D000818:Animals; D002107:Caenorhabditis / Q000166:cytology / Q000235:genetics*; D002454:Cell Differentiation; D002874:Chromosome Mapping; D004303:Dosage Compensation, Genetic; D009154:Mutation; D010641:Phenotype