Heterotrimeric G protein signaling governs the cortical stability during apical constriction in Drosophila gastrulation

► In Drosophila mesoderm invagination, ventral cells constrict their apical surfaces. ► Heterotrimetic G protein signaling is required for apical constriction. ► We found that G protein is also required for the organisation of cortical actin. ► Disruption of cortical actin induced membrane blebbing during apical constriction. ► G protein confers physical stability on the cell surface during morphogenesis.