PT - JOURNAL ARTICLE AU - Pau Pulido Companys AU - Anneliese Norris AU - Marcus Bischoff TI - Cellular contractility coordinates cytoskeletal dynamics and cell behaviour during <em>Drosophila</em> abdominal morphogenesis AID - 10.1101/672006 DP - 2019 Jan 01 TA - bioRxiv PG - 672006 4099 - http://biorxiv.org/content/early/2019/06/28/672006.short 4100 - http://biorxiv.org/content/early/2019/06/28/672006.full AB - During morphogenesis, cells undergo various behaviours, such as migration and constriction, which need to be coordinated. How this is achieved remains elusive. During morphogenesis of the Drosophila adult abdominal epidermis, larval epithelial cells (LECs) migrate directedly before constricting apically and undergoing apoptosis. Here, we study the mechanisms underlying the transition from migration to constriction. We show that LECs possess a pulsatile apical actomyosin network and that a change in network polarity underlies behavioural change. Exploring the properties of the contractile network, we find that the level of cell contractility impacts on the network’s behaviour, as well as on overall cytoskeletal architecture and cell behaviour. We also find that pulsed contractions occur only in cells with intermediate levels of contractility. Furthermore, increasing levels of the small Rho GTPase Rho1 disrupts pulsed contractions, and instead leading to cells that cycle between two states, characterised by a junctional cortical and an apicomedial actin network. Our results highlight that behavioural change relies on tightly controlled cellular contractility. Moreover, we show that constriction can occur without pulsed contractions, raising questions about their contribution to constriction.