CYK-1/Formin activation in cortical RhoA signaling centers promotes organismal left–right symmetry breaking

Abstract

SignificanceActive torque generation in the actin cytoskeleton has been implicated in driving left–right symmetry breaking of developing embryos, but which molecules generate the active torque and how active torque generation is organized subcellularly remain unclear. This study shows that cortical Formin, recruited to cortical regions where RhoA signaling is active, promotes active torque generation in the actomyosin layer. We find that active torque tends to locally rotate the cortex in a clockwise fashion, which drives the emergence of chiral counterrotating flows with consistent handedness and facilitates left–right symmetry breaking ofC. elegansembryos.