title: The hedgehog-related gene wrt-5 is essential for hypodermal development in Caenorhabditis elegans.
abstract: The Caenorhabditis elegans genome encodes a series of hedgehog-related genes, which are thought to have evolved and diverged from an ancestral Hh gene. They are classified into several families based on their N-terminal domains. Here, we analyze the expression and function of a member of the warthog gene family, wrt-5, that lacks the Hint/Hog domain. wrt-5 is expressed in seam cells, the pharynx, pharyngeal-intestinal valve cells, neurons, neuronal support cells, the excretory cell, and the reproductive system. WRT-5 protein is secreted into the extracellular space during embryogenesis. Furthermore, during larval development, WRT-5 protein is secreted into the pharyngeal lumen and the pharyngeal expression changes in a cyclical manner in phase with the molting cycle. Deletion mutations in wrt-5 cause embryonic lethality, which are temperature sensitive and more severe at 15 degrees C than at 25 degrees C. Animals that hatch exhibit variable abnormal morphology, for example, bagging worms, blistering, molting defects, or Roller phenotypes. We examined hypodermal cell junctions using the AJM-1Colon, two colonsGFP marker in the wrt-5 mutant background and observed cell boundary abnormalities in the arrested embryos. AJM-1Colon, two colonsGFP protein is also misplaced in pharyngeal muscle cells in the absence of WRT-5. In conclusion, we show that wrt-5 is an essential gene that - despite its lack of a Hint domain - has multiple functions in C. elegans and is implicated in cell shape integrity.
authors.affiliation: Department of Biosciences at Novum, and Center for Genomics and Bioinformatics, Karolinska Institutet, Hälsovägen 7, SE-141 57 Huddinge, Sweden.
authors.forename: Limin
authors.initials: L
authors.lastname: Hao
authors.forename: Gudrun
authors.initials: G
authors.lastname: Aspöck
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Bürglin
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002107:Caenorhabditis; D017173:Caenorhabditis elegans / Q000196:embryology*; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000502:physiology*; D002450:Cell Communication; D003001:Cloning, Molecular; D003080:Cold Temperature; D005091:Exons; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D005819:Genetic Markers; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000378:metabolism; D053823:Hedgehog Proteins; D007091:Image Processing, Computer-Assisted; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D010614:Pharynx / Q000196:embryology; D010641:Phenotype; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D040521:Subcutaneous Tissue / Q000196:embryology*; D013696:Temperature; D014018:Tissue Distribution; D015534:Trans-Activators / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*
chemical_list: D029742:Caenorhabditis elegans Proteins; D005819:Genetic Markers; D053823:Hedgehog Proteins; D015534:Trans-Activators; C509283:WRT-5 protein, C elegans; D049452:Green Fluorescent Proteins