Fig. 6.

Episodes of adaptive selection identified upon separately analyzing vertebrate DNA/RNA-modifying METTLs and vertebrate protein-modifying METTLs. (A) The physical positions of adaptive selection episodes involved in the diversification of METTLs that modify DNA/RNA nucleosides (top) and METTLs that modify protein residues (bottom). Numbers of synonymous (blue bars) and nonsynonymous (red bars) substitutions at codon positions that are subject to significant episodes of diversifying selection in vertebrates (P value < 0.05). (B) Phylogenetic location of the mutations involved in such episodes for DNA/RNA-modifying METTLs, indicated by a light blue background, and (C) protein-modifying METTLs, indicated by a light red background. For figure readability, “METTL” has been removed from the names of each tip label (e.g., “METTL1” is simply displayed as “1”). Branches in red account for higher numbers of nonsynonymous mutations, branches in blue indicate higher numbers of synonymous mutations, and branches in green represent cases with the same numbers of nonsynonymous and synonymous mutations.