Differential positioning of adherens junctions is associated with initiation of epithelial folding

摘要: During tissue morphogenesis, simple epithelial sheets undergo folding to form complex structures. The prevailing model underlying involves cell shape changes driven by myosin-dependent apical constriction. Here we describe an alternative mechanism that requires differential positioning of adherens junctions controlled modulation apical-basal polarity. Using live embryo imaging, show before the initiation dorsal transverse folds during Drosophila gastrulation, shift basally in initiating cells, but maintain their original subapical neighbouring cells. Junctional epithelium depends on polarity proteins Bazooka and Par-1. In particular, basal occurs cells is associated with a progressive decrease Par-1 levels. We uniform reduction activity or results lateral each case fold abolished. addition, increase Bazooka/Par-1 ratio causes formation ectopic folds. not only alters also forces membrane adjacent bend towards thereby facilitating deformation. Our data thus establish direct link between modification folding.