Conservation of dorsal-ventral patterning in arthropods and chordates.

ABSTRACT

Dorsal-ventral patterning within the ectodermal and mesodermal germ layers of Drosophila and Xenopus embryos is specified by a system of genes that has been conserved over 500 million years of evolution. In both organisms, the activity of the TGF-beta family member DPP/BMP4 is antagonized by SOG/CHORDIN. A second Xenopus gene, noggin, has a similar biological activity to chordin. Analysis of the action of these genes indicate that Spemann's organizer promotes dorsal cell fates in Xenopus by antagonizing a ventralizing signal encoded by the Bmp4 gene.