Apical constriction during embryogenesis is driven by self-assembled actomyosin networks that spontaneously develop radial polarity and pulsing.

Abstract

During embryogenesis, cells exert coordinated forces to sculpt tissues into complex shapes that are precursors of organs and other specialized structures. Apical constriction is a conserved deformation mode that contracts and folds tissues. In many organisms, apical constriction is driven by contractile pulses generated by apical actomyosin cellular networks (Martin and Goldstein, 2014) with radial polarity: formins and actin filament barbed ends localize to peripheral cell-cell junctions, while actin filaments point inwards with myosin II in the medial apical zone (Mason et al., 2013).