A role for microfilament-based contraction in branching morphogenesis of the ureteric bud

A role for microfilament-based contraction in branching morphogenesis of the ureteric bud. Background. Branching morphogenesis of the ureteric bud/collecting duct epithelium is an important feature of kid-ney development. Recent work has identified many transcrip-tion factors and paracrine signaling molecules that regulate branching, but the physical mechanisms by which these signals act remain largely unknown. The actin cytoskeleton is a com-mon component of mechanisms of morphogenesis. We have therefore studied the expression of, and requirement for actin filaments in the ureteric bud, a branching epithelium of the mammalian kidney. Methods. Embryonic kidney rudiments were grown in or-gan culture. Actin expression in kidneys growing normally and those in which branching was inhibited was examined using la