title: Genetic analysis of the roles of daf-28 and age-1 in regulating Caenorhabditis elegans dauer formation.
abstract: Based on environmental cues, the nervous system of Caenorhabditis elegans regulates formation of the dauer larva, an alternative larval form specialized for long-term survival under harsh conditions. Mutations that cause constitutive or defective dauer formation (Daf-c or Daf-d) have been identified and the genes ordered in a branched pathway. Most Daf-c mutations also affect recovery from the dauer stage. The semi-dominant mutation daf-28(sa191) is Daf-c but has no apparent effect on dauer recovery. We use this unique aspect of daf-28(sa191) to characterize the effects of several Daf-d and synthetic Daf-c mutations on dauer recovery. We present double mutant analysis that indicates that daf-28(sa191) acts at a novel point downstream in the genetic pathway for dauer formation. We also show that daf-28(sa191) causes a modest increase (12-13%) in life span. The phenotypes and genetic interactions of daf-28(sa191) are most similar to those of daf-2 and daf-23 mutations, which also cause a dramatic increase in life span. We present mapping and complementation data that suggest that daf-23 is the same gene as age-1, identified previously by mutations that extend life span. We find that age-1 alleles are also Daf-c at 27 degrees.
authors.affiliation: Department of Genetics, University of Washington, Seattle 98195, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Malone
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: J H
authors.initials: JH
authors.lastname: Thomas
mesh_terms: D000483:Alleles; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development*; D004843:Epistasis, Genetic; D009154:Mutation