title: Suppressors of the organ-specific differentiation gene pha-1 of Caenorhabditis elegans.
abstract: The embryonic lethal gene pha-1 of the nematode Caenorhabditis elegans is required for late differentiation and morphogenesis of the pharynx in the developing embryo. Revertants of two temperature-sensitive alleles of pha-1 were isolated with the aim of obtaining mutations in genes that interact with pha-1. By various methods of mutagenesis, chemical, X-ray, transposon, or by spontaneous reversion, 220 recessive revertants were obtained, defining three complementation groups. The largest, sup-35 on linkage group (LG) III, maps close to but is separable from pha-1. This suppressor can exert its effect either maternally or zygotically to allow survival of pha-1(ts) embryos. The other two, sup-36 and sup-37, are required zygotically and map on LGIV and LGV, respectively. We have not noted a phenotype distinguishing any of the suppressors from wild type except for suppression of pha-1. That suppression is the null phenotype of at least sup-35 is indicated by the high frequency of mutation and by the fact that heterozygotes carrying sup-35 and a deficiency spanning the locus are also able to suppress. Five spontaneous mutations in sup-35 were found to be associated with recombination.
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Tübingen, Federal Republic of Germany.
authors.forename: H
authors.initials: H
authors.lastname: Schnabel
authors.forename: G
authors.initials: G
authors.lastname: Bauer
authors.forename: R
authors.initials: R
authors.lastname: Schnabel
mesh_terms: D000818:Animals; D002107:Caenorhabditis / Q000187:drug effects / Q000196:embryology / Q000235:genetics* / Q000528:radiation effects; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004251:DNA Transposable Elements / Q000235:genetics; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005804:Genes, Lethal / Q000235:genetics*; D005809:Genes, Regulator / Q000235:genetics*; D016153:Genes, Suppressor / Q000235:genetics*; D005816:Genetic Complementation Test; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D013696:Temperature
chemical_list: D004251:DNA Transposable Elements; D005020:Ethyl Methanesulfonate