title: Communication between distant epithelial cells by filopodia-like protrusions during embryonic development.
abstract: Long-range intercellular communication is essential for the regulation of embryonic development. Apart from simple diffusion, various modes of signal transfer have been described in the literature. Here, we describe a novel type of cellular extensions found in epithelial cells of the somites in chicken embryos. These filopodia-like protrusions span the subectodermal space overlying the dorsal surface of the somites and contact the ectoderm. We show that these protrusions are actin- and tubulin-positive and require Rac1 for their formation. The presence of glycophosphatidylinositol-anchored proteins and net retrograde trafficking of the transmembrane Wnt-receptor Frizzled-7 along the protrusions indicate their role in signal transport and distribution. Taken together, our data suggest a role of filopodia-like protrusions in mediating signaling events between distant epithelial cells during embryonic development.
authors.affiliation: Institute of Anatomy II, Department of Vertebrate Embryology, University of Cologne, Joseph-Stelzmann-Straße 9, Cologne 50931, Germany Institute of Anatomy and Cell Biology, Department of Molecular Embryology, University of Freiburg, Albertstraße 17, Freiburg 79104, Germany Faculty of Biology, University of Freiburg, Schaenzlestraße 1, Freiburg 79104, Germany.
authors.lastname: Sagar
authors.affiliation: Institute of Anatomy II, Department of Vertebrate Embryology, University of Cologne, Joseph-Stelzmann-Straße 9, Cologne 50931, Germany.
authors.forename: Felicitas
authors.initials: F
authors.lastname: Pröls
authors.affiliation: Institute of Molecular and Cellular Anatomy, University of Ulm, Albert-Einstein-Allee 11, Ulm 89081, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Wiegreffe
authors.affiliation: Institute of Anatomy II, Department of Vertebrate Embryology, University of Cologne, Joseph-Stelzmann-Straße 9, Cologne 50931, Germany Institute of Anatomy and Cell Biology, Department of Molecular Embryology, University of Freiburg, Albertstraße 17, Freiburg 79104, Germany martin.scaal@uk-koeln.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Scaal
mesh_terms: D000818:Animals; D002642:Chick Embryo; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism*; D051157:Frizzled Receptors / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D011554:Pseudopodia / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D051157:Frizzled Receptors; D020830:rac1 GTP-Binding Protein
keywords: Dermomyotome; FiLiPs; Filopodia; Frizzled-7; Somite