title: lin-35 Rb acts in the major hypodermis to oppose ras-mediated vulval induction in C. elegans.
abstract: Specification of vulval precursor cell (VPC) fates in C. elegans has served as an important signal transduction paradigm. Genetic studies have indicated that a large group of synthetic multivulva (SynMuv) genes, including the Rb ortholog lin-35, antagonizes the activity of the EGF receptor-Ras-MAP kinase pathway during VPC specification. A prevalent view has been that Rb-mediated transcriptional regulation and chromatin remodeling activities act in the VPCs to antagonize Ras activation through effects on promoters of target genes of the EGF receptor-Ras-MAP kinase pathway that promote vulval fates. Here, we have investigated the cellular focus of lin-35 using conventional genetic mosaic analysis and tissue-specific expression. Our results indicate that lin-35 activity is required in the major hypodermal syncytium and not in the VPCs to inhibit vulval fates. LIN-35 Rb may inhibit vulval fates by regulating a signal from hyp7 to the VPCs or the physiological state of hyp7.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10032, USA.
authors.forename: Toshia R
authors.initials: TR
authors.lastname: Myers
authors.forename: Iva
authors.initials: I
authors.lastname: Greenwald
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000502:physiology*; D019070:Cell Lineage; D004627:Embryonic Induction / Q000502:physiology; D066246:ErbB Receptors; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008845:Microinjections / Q000379:methods; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D013234:Stem Cells / Q000502:physiology; D040521:Subcutaneous Tissue / Q000196:embryology / Q000378:metabolism*; D014844:Vulva / Q000166:cytology* / Q000196:embryology; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D029742:Caenorhabditis elegans Proteins; D012097:Repressor Proteins; C116485:lin-35 protein, C elegans; D049452:Green Fluorescent Proteins; D066246:ErbB Receptors; D020928:Mitogen-Activated Protein Kinases; D018631:ras Proteins