MOLECULAR-CLONING AND FUNCTIONAL-ANALYSIS OF A NEW ACTIVIN BETA-SUBUNIT - A DORSAL MESODERM-INDUCING ACTIVITY IN XENOPUS

A cDNA that encodes a new member of the TGF-beta superfamily most simi lar to activin beta A, beta B, and recently reported beta C has been i solated from Xenopus laevis. Expression of the gene in early embryos s uggested its biological importance in Xenopus embryogenesis. Microinje ction of a synthetic mRNA transcribed from the cDNA into ventral blast omeres of early Xenopus embryo led to the formation of secondary body axis. Mesodermal marker genes were induced in isolated animal cap by a similar mRNA injection. These results demonstrate that the gene encod es a new member of activin subfamily whose function is closely related to mesoderm induction. (C) 1995 Academic Press, Inc.