title: Planar polarity and actin dynamics in the epidermis of Drosophila.
abstract: Dorsal closure is a morphogenetic process involving the coordinated convergence of two epithelial sheets to enclose the Drosophila melanogaster embryo. Specialized populations of cells at the edges of each epithelial sheet, the dorsal-most epidermal cells, emit actin-based processes that are essential for the proper enclosure of the embryo. Here we show that actin dynamics at the leading edge is preceded by a planar polarization of the dorsal-most epidermal cells associated with a reorganization of the cytoskeleton. An important consequence of this planar polarization is the formation of actin-nucleating centres at the leading edge, which are important in the dynamics of actin. We show that Wingless (Wg) signalling and Jun amino-terminal kinase (JNK) signalling have overlapping but different roles in these events.
authors.affiliation: Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Kaltschmidt
authors.forename: Nicola
authors.initials: N
authors.lastname: Lawrence
authors.forename: Véronique
authors.initials: V
authors.lastname: Morel
authors.forename: Tina
authors.initials: T
authors.lastname: Balayo
authors.forename: Beatriz García
authors.initials: BG
authors.lastname: Fernández
authors.forename: Anne
authors.initials: A
authors.lastname: Pelissier
authors.forename: Antonio
authors.initials: A
authors.lastname: Jacinto
authors.forename: Alfonso
authors.initials: A
authors.lastname: Martinez Arias
mesh_terms: D000199:Actins / Q000235:genetics / Q000502:physiology*; D000818:Animals; D016764:Cell Polarity / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology; D004331:Drosophila melanogaster / Q000166:cytology* / Q000196:embryology / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology; D000078404:Epidermal Cells; D004817:Epidermis / Q000502:physiology*; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000502:physiology; D009024:Morphogenesis / Q000235:genetics; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D051155:Wnt1 Protein
chemical_list: D000199:Actins; D029721:Drosophila Proteins; D011518:Proto-Oncogene Proteins; D051155:Wnt1 Protein; C074622:wg protein, Drosophila; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases