DROSOPHILA 60A GENE, ANOTHER TRANSFORMING GROWTH-FACTOR-BETA FAMILY MEMBER, IS CLOSELY RELATED TO HUMAN BONE MORPHOGENETIC PROTEINS

The 60A gene, a member of the transforming growth factor-beta-superfamily of signaling proteins, has been identified in Drosophila melanogaster. From its inferred protein sequence we predict the precursor is secreted and processed to release a growth factor-like molecule. The 60A gene is expressed throughout development with peaks of transcription during early embryogenesis, in pupae, and in adult males. The putative 60A protein shows greater sequence similarity to three vertebrate family members (human bone morphogenetic proteins 5, 6, and 7) than to its only Drosophila relative, the protein product of the decapentaplegic (dpp) gene. This observation suggests that the duplication event that gave rise to the two transforming growth factor-beta-like proteins in Drosophila predates the divergence of chordates and arthropods.