title: Dishevelled is essential for neural connectivity and planar cell polarity in planarians.
abstract: The Wingless/Integrated (Wnt) signaling pathway controls multiple events during development and homeostasis. It comprises multiple branches, mainly classified according to their dependence on β-catenin activation. The Wnt/β-catenin branch is essential for the establishment of the embryonic anteroposterior (AP) body axis throughout the phylogenetic tree. It is also required for AP axis establishment during planarian regeneration. Wnt/β-catenin-independent signaling encompasses several different pathways, of which the most extensively studied is the planar cell polarity (PCP) pathway, which is responsible for planar polarization of cell structures within an epithelial sheet. Dishevelled (Dvl) is the hub of Wnt signaling because it regulates and channels the Wnt signal into every branch. Here, we analyze the role of Schmidtea mediterranea Dvl homologs (Smed-dvl-1 and Smed-dvl-2) using gene silencing. We demonstrate that in addition to a role in AP axis specification, planarian Dvls are involved in at least two different β-catenin-independent processes. First, they are essential for neural connectivity through Smed-wnt5 signaling. Second, Smed-dvl-2, together with the S. mediterranea homologs of Van-Gogh (Vang) and Diversin (Div), is required for apical positioning of the basal bodies of epithelial cells. These data represent evidence not only of the function of the PCP network in lophotrocozoans but of the involvement of the PCP core elements Vang and Div in apical positioning of the cilia.
authors.affiliation: Department of Genetics and Institute of Biomedicine, University of Barcelona, E-08028 Barcelona, Catalonia, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Almuedo-Castillo
authors.forename: Emili
authors.initials: E
authors.lastname: Saló
authors.forename: Teresa
authors.initials: T
authors.lastname: Adell
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D016000:Cluster Analysis; D000072261:Dishevelled Proteins; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010932:Planarians / Q000502:physiology*; D034622:RNA Interference; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000502:physiology; D051153:Wnt Proteins / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000072261:Dishevelled Proteins; D010750:Phosphoproteins; D051153:Wnt Proteins