title: PDGF-A controls mesoderm cell orientation and radial intercalation during Xenopus gastrulation.
abstract: Radial intercalation is a common, yet poorly understood, morphogenetic process in the developing embryo. By analyzing cell rearrangement in the prechordal mesoderm during Xenopus gastrulation, we have identified a mechanism for radial intercalation. It involves cell orientation in response to a long-range signal mediated by platelet-derived growth factor (PDGF-A) and directional intercellular migration. When PDGF-A signaling is inhibited, prechordal mesoderm cells fail to orient towards the ectoderm, the endogenous source of PDGF-A, and no longer migrate towards it. Consequently, the prechordal mesoderm fails to spread during gastrulation. Orientation and directional migration can be rescued specifically by the expression of a short splicing isoform of PDGF-A, but not by a long matrix-binding isoform, consistent with a requirement for long-range signaling.
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada.
authors.forename: Erich W
authors.initials: EW
authors.lastname: Damm
authors.forename: Rudolf
authors.initials: R
authors.lastname: Winklbauer
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D054262:Gastrulation / Q000235:genetics / Q000502:physiology*; D017403:In Situ Hybridization; D008648:Mesoderm / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D014981:Xenopus; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010982:Platelet-Derived Growth Factor; D029867:Xenopus Proteins; C075278:platelet-derived growth factor A