SLCO solute carrier gene family evolution in primates (H. sapiens, M. mulatta, and M. fascicularis). (A) Phylogenetic tree of SLCO divergence based on DNAML maximum likelihood analysis from the PHYLIP software package. Human orthologs of SLCO-encoding genes were identified in the draft genomes of M. fascicularis and M. mulatta, and the calculated sequence relationship is shown in “substitution events per residue” units. Thin black lines denote long-distance relationships, and bold lines are used to display closer relationships, shown at 10-fold magnification for better resolution. Gray lines and red lines mark separate evolution in macaques and humans, respectively. The drug transporters SLCO1B3 and LST (RefSeq NM_001009562) show the highest degree of sequence diversity within macaques (marked by yellow circles). Differences below 0.35% within the macaques are marked by blue and green symbols. For simplicity, “SLCO” was omitted for labeling of individual family members. (B) Independent diversification of SLCO genes in primates. SLCO sequence divergence between M. fascicularis and human (Mf and Hs; x-axis), and between M. fascicularis and M. mulatta (Mf and Mm; y-axis) orthologs are displayed. SLCO6A1 shows the highest divergence between M. fascicularis and humans, and SLCO1B3 is the most diverse gene of the SLCO family within macaques. The black line indicates the average value and the hatched lines indicate ±SD. Note the different scales of the x- and y-axis.