PT - JOURNAL ARTICLE AU - Thanh TK Vuong-Brender AU - Martine Ben Amar AU - Julien Pontabry AU - Michel Labouesse TI - The interplay of stiffness and force anisotropies drive embryo elongation AID - 10.1101/095752 DP - 2016 Jan 01 TA - bioRxiv PG - 095752 4099 - http://biorxiv.org/content/early/2016/12/20/095752.short 4100 - http://biorxiv.org/content/early/2016/12/20/095752.full AB - The morphogenesis of tissues, like the deformation of an object, results from the interplay between their material properties and the mechanical forces exerted on them. Whereas the importance of mechanical forces in influencing cell behaviour is widely recognized, the importance of tissue material properties, in particular stiffness, has received much less attention. Using C. elegans as a model, we examine how both aspects contribute to embryonic elongation. Measuring the opening shape of the epidermal actin cortex after laser nano-ablation, we assess the spatiotemporal changes of actomyosin-dependent force and stiffness along the antero-posterior and dorso-ventral axis. Experimental data and analytical modelling show that myosin II-dependent force anisotropy within the lateral epidermis, and stiffness anisotropy within the fiber-reinforced dorso-ventral epidermis are critical to drive embryonic elongation. Together, our results establish a quantitative link between cortical tension, material properties and morphogenesis of an entire embryo.