title: Maintenance of the intestinal tube in Caenorhabditis elegans: the role of the intermediate filament protein IFC-2.
abstract: The Caenorhabditis elegans intestinal lumen is surrounded by a dense cytoplasmic network that is laterally attached to the junctional complex and is referred to as the endotube. It localizes to the terminal web region which anchors the microvillar actin filament bundles and is particularly rich in intermediate filaments. To examine their role in intestinal morphogenesis and function, C. elegans reporter strains were generated expressing intestine-specific CFP-tagged intermediate filament polypeptide IFB-2. When these animals were treated with dsRNA against intestinal intermediate filament polypeptide IFC-2, the endotube developed multiple bubble-shaped invaginations that protruded into the enterocytic cytoplasm. The irregularly widened lumen remained surrounded by a continuous IFB-2::CFP-labeled layer. Comparable but somewhat mitigated phenotypic changes were also noted in wild-type N2 worms treated with ifc-2 (RNAi). Junctional complexes were ultrastructurally and functionally normal and the apical domain of intestinal cells was also not altered. These observations demonstrate that IFC-2 is important for structural maintenance of the intestinal tube but is not needed for establishment of the endotube and epithelial cell polarity.
authors.affiliation: Department of Anatomy and Cell Biology, Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Hüsken
authors.forename: Tobias
authors.initials: T
authors.lastname: Wiesenfahrt
authors.forename: Christian
authors.initials: C
authors.lastname: Abraham
authors.forename: Reinhard
authors.initials: R
authors.lastname: Windoffer
authors.forename: Olaf
authors.initials: O
authors.lastname: Bossinger
authors.forename: Rudolf E
authors.initials: RE
authors.lastname: Leube
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000502:physiology* / Q000648:ultrastructure; D016764:Cell Polarity / Q000235:genetics / Q000502:physiology; D004847:Epithelial Cells / Q000166:cytology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D007381:Intermediate Filament Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000166:cytology* / Q000648:ultrastructure; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission
chemical_list: D029742:Caenorhabditis elegans Proteins; C533714:IFC-2 protein, C elegans; D007381:Intermediate Filament Proteins