Abstract : Tissue morphogenesis is driven by local cellular deformations that are powered by contractile actomyosin networks. How localized forces are transmitted across tissues to shape them at a mesoscopic scale is still unclear. Analyzing gastrulation in entire avian embryos, we show that it is driven by the graded contraction of a large-scale supracellular actomyosin ring at the margin between the embryonic and extraembryonic territories. The propagation of these forces is enabled by a fluid-like response of the epithelial embryonic disk, which depends on cell division. A simple model of fluid motion entrained by a tensile ring quantitatively captures the vortex-like "polonaise" movements that accompany the formation of the primitive streak. The geometry of the early embryo thus arises from the transmission of active forces generated along its boundary.
https://hal-pasteur.archives-ouvertes.fr/pasteur-02905796 Contributor : Corinne BillionConnect in order to contact the contributor Submitted on : Thursday, July 23, 2020 - 5:14:17 PM Last modification on : Monday, May 9, 2022 - 11:58:08 AM Long-term archiving on: : Tuesday, December 1, 2020 - 7:08:47 PM
Mehdi Saadaoui, Didier Rocancourt, Julian Roussel, Francis Corson, Jerome Gros. A tensile ring drives tissue flows to shape the gastrulating amniote embryo. Science, American Association for the Advancement of Science (AAAS), 2020, 367 (6476), pp.453-458. ⟨10.1126/science.aaw1965⟩. ⟨pasteur-02905796⟩