Molecular cloning of bone morphogenetic protein (BMP) gene from the planarian Dugesia japonica

BMP (Bone Morphogenetic Protein) acts as a morphogen for dorso-ventral patt erning and organogenesis in both vertebrate and invertebrate development. A cDNA encoding BMP (named Djbmp) has been cloned and sequenced from the pla narian Dugesia japonica. The mature form of DjBMP which was deduced from th e cDNA sequence was composed of 114 amino acid residues. The position of se ven cysteine residues of the mature DjBMP was highly conserved among the TG F-beta superfamily. DjBMP had high similarity to human BMP-2A (50% amino ac id identity), BMP-4 (49%) and Drosophila decapentaplegic protein (48%), ind icating that DjBMP belongs to DVR (decapentaplegic-Vg1-related) group. The expression pattern in intact and regenerating planarians revealed by whole mount in situ hybridization suggested that the DjBMP plays a role not only in dorso-ventral but also in mid-lateral body patterning.