... synthesized in the Spemannorganizer, namely Follistatin, Chordin and Noggin[12]. These proteins are antagonists of BMP and othermembers of the TGF-b family, binding to and inhibit-ing these ... embryos, the din mutant is not rescued.Expression of chordin is induced by Sizzled in embryoswith Chordin, but not in the absence of Chordin.These results indicate that Chordin is required for ... these signaling molecules from binding to theirreceptors in the extracellular space, thus inhibiting ven-tralizing activities. Of these proteins, Chordin has along-range effect. In Xenopus,...