Studies show new players and patterns in vertebrate heart development

Cell biologists have identified proteins capable of promoting heart development -- at least in frogs and birds. They report that the proteins Dkk1 and Crescent, which inhibit regulatory proteins of the Wnt family, can induce formation of a beating heart in tissue culture from Xenopus laevis and chick embryos. Other Wnt antagonists lacked this activity. The findings indicate that diffusion of Dkk1 and Crescent from organizer centers in the embryos initiates cardiogenesis by establishing a zone of low Wnt activity.