Molecular phylogenetic tree of the TGFβ superfamily. (A) This tree was inferred using the ML method assuming the JTT+I+Γ4 model (α= 0.85). Only the C-end mature ligand domain highly conserved throughout the TGFβ superfamily (62 amino acid sites) was employed in the analysis. Green, blue, red, and yellow dots indicate sequences of fly (Drosophila melanogaster), zebrafish, human, and amphioxus (Branchiostoma floridae), respectively. Note that some sequences of fly and amphioxus with many unique gaps were excluded from this analysis. All available human homologs were included. Zebrafish sequences are included only for bmp2/4 and bmp16 genes as well as anti-dorsalizing morphogenetic protein where there is no human ortholog available. (B) A molecular phylogenetic tree of Bmp2, -4 and -16. This was estimated as the ML tree assuming the JTT+I+Γ4 model (α= 0.93). 82 amino acid sites were used in the analysis. Support values at nodes are shown in order, bootstrap probabilities in the ML analysis, bootstrap probabilities in the neighbor-joining analysis, and Bayesian posterior probabilities.