Roles of the BMP family in pattern formation of the vertebrate limb

Abstract

In the process of limb development, various signaling molecules are produced in the organizing center of the limb bud. These molecules regulate pattern formation and the morphogenesis of the limb. Members of the bone morphogenetic protein (BMP) family and their receptors are expressed in the limb bud in spatiotemporal specific patterns. BMP signaling regulates chondrogenesis of limb mesenchyme, and promotes apoptosis of the interdigital soft tissue. Recently, this signaling was found to be involved in establishment of dorsoventral polarity of the limb bud and in regulation of limb growth via maintenance of the apical ectodermal ridge. BMPs also regulate digit morphology. In these events, BMPs work together with other signaling molecules, but they sometimes act as negative regulators of these other molecules so that limb morphogenesis can proceed normally.