--- res: bibo_abstract: - The actomyosin cytoskeleton is a primary force-generating mechanism in morphogenesis, thus a robust spatial control of cytoskeletal positioning is essential. In this report, we demonstrate that actomyosin contractility and planar cell polarity (PCP) interact in post-mitotic Ciona notochord cells to self-assemble and reposition actomyosin rings, which play an essential role for cell elongation. Intriguingly, rings always form at the cells′ anterior edge before migrating towards the center as contractility increases, reflecting a novel dynamical property of the cortex. Our drug and genetic manipulations uncover a tug-of-war between contractility, which localizes cortical flows toward the equator and PCP, which tries to reposition them. We develop a simple model of the physical forces underlying this tug-of-war, which quantitatively reproduces our results. We thus propose a quantitative framework for dissecting the relative contribution of contractility and PCP to the self-assembly and repositioning of cytoskeletal structures, which should be applicable to other morphogenetic events.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Ivonne foaf_name: Sehring, Ivonne foaf_surname: Sehring - foaf_Person: foaf_givenName: Pierre foaf_name: Recho, Pierre foaf_surname: Recho - foaf_Person: foaf_givenName: Elsa foaf_name: Denker, Elsa foaf_surname: Denker - foaf_Person: foaf_givenName: Matthew foaf_name: Kourakis, Matthew foaf_surname: Kourakis - foaf_Person: foaf_givenName: Birthe foaf_name: Mathiesen, Birthe foaf_surname: Mathiesen - foaf_Person: foaf_givenName: Edouard B foaf_name: Hannezo, Edouard B foaf_surname: Hannezo foaf_workInfoHomepage: http://www.librecat.org/personId=3A9DB764-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0001-6005-1561 - foaf_Person: foaf_givenName: Bo foaf_name: Dong, Bo foaf_surname: Dong - foaf_Person: foaf_givenName: Di foaf_name: Jiang, Di foaf_surname: Jiang bibo_doi: 10.7554/eLife.09206 bibo_volume: 4 dct_date: 2015^xs_gYear dct_language: eng dct_publisher: eLife Sciences Publications@ dct_title: Assembly and positioning of actomyosin rings by contractility and planar cell polarity@ ...