title: SDF-9, a protein tyrosine phosphatase-like molecule, regulates the L3/dauer developmental decision through hormonal signaling in C. elegans.
abstract: The dauer larva of the nematode Caenorhabditis elegans is a good model system for investigating the regulation of developmental fates by environmental cues. Here we show that SDF-9, a protein tyrosine phosphatase-like molecule, is involved in the regulation of dauer larva formation. The dauer larva of sdf-9 mutants is different from a normal dauer larva but resembles the dauer-like larva of daf-9 and daf-12 dauer-constitutive mutants. Like these mutants, the dauer-constitutive phenotypes of sdf-9 mutants were greatly enhanced by cholesterol deprivation. Epistasis analyses, together with the relationship between sdf-9 mutations and daf-9 expression, suggested that SDF-9 increases the activity of DAF-9 or helps the execution of the DAF-9 function. SDF-9 was expressed in two head cells in which DAF-9 is expressed. By their position and by genetic mosaic experiments, we identified these cells as XXXL/R cells, which are known as embryonic hypodermal cells and whose function at later stages is unknown. Killing of the sdf-9-expressing cells in the wild-type first-stage larva induced formation of the dauer-like larva. Since this study on SDF-9 and former studies on DAF-9 showed that the functions of these proteins are related to those of steroids, XXXL/R cells seem to play a key role in the metabolism or function of a steroid hormone(s) that acts in dauer regulation.
authors.affiliation: Structural Biology Center, National Institute of Genetics and School of Genetics, Faculty of Life Sciences, Graduate University for Advanced Studies, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Ohkura
authors.forename: Norio
authors.initials: N
authors.lastname: Suzuki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishihara
authors.forename: Isao
authors.initials: I
authors.lastname: Katsura
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000502:physiology*; D002784:Cholesterol / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006728:Hormones / Q000378:metabolism*; D007814:Larva / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry* / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013256:Steroids / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014018:Tissue Distribution; D019076:Transgenes
chemical_list: D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D006728:Hormones; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D013256:Steroids; D049452:Green Fluorescent Proteins; D002784:Cholesterol; D017027:Protein Tyrosine Phosphatases; C476241:SDF-9 protein, C elegans