title: Amnioserosa cell constriction but not epidermal actin cable tension autonomously drives dorsal closure.
abstract: Tissue morphogenesis requires coordination of multiple force-producing components. During dorsal closure in fly embryogenesis, an epidermis opening closes. A tensioned epidermal actin/MyosinII cable, which surrounds the opening, produces a force that is thought to combine with another MyosinII force mediating apical constriction of the amnioserosa cells that fill the opening. A model proposing that each force could autonomously drive dorsal closure was recently challenged by a model in which the two forces combine in a ratchet mechanism. Acute force elimination via selective MyosinII depletion in one or the other tissue shows that the amnioserosa tissue autonomously drives dorsal closure while the actin/MyosinII cable cannot. These findings exclude both previous models, although a contribution of the ratchet mechanism at dorsal closure onset remains likely. This shifts the current view of dorsal closure being a combinatorial force-component system to a single tissue-driven closure event.
authors.affiliation: Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Laurynas
authors.initials: L
authors.lastname: Pasakarnis
authors.affiliation: Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Erich
authors.initials: E
authors.lastname: Frei
authors.affiliation: Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Caussinus
authors.affiliation: Growth &Development, Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Affolter
authors.affiliation: Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Damian
authors.initials: D
authors.lastname: Brunner
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000205:Actomyosin / Q000378:metabolism; D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D003250:Constriction; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology* / Q000196:embryology*; D000078404:Epidermal Cells; D009024:Morphogenesis / Q000502:physiology*
chemical_list: D000199:Actins; D029721:Drosophila Proteins; D000205:Actomyosin