Frequency of nucleotide substitutions in ciHHV-6 genes compared to those in reference viral genomes. (A) Substitution frequencies in each gene are shown for the 21 ciHHV-6B genomes in comparison with HHV-6B strain HST (Japan) and Z29 (Democratic Republic of the Congo) genomes (top and middle, respectively) and the ciHHV-6B genome in European HAPMAP NA10863 (bottom). The color coding shown in the key matches that of the network in Fig. 3B as follows: European group 1, pale-blue lines; European group 2, orange lines; European group 3, green lines; European singletons, gray lines; ciHHV-6B in HGDP00813 from China, red lines; and ciHHV-6B in HGDP00092 from Pakistan, black lines. (B) Substitution frequency in each gene for each of the 7 ciHHV-6A genomes in comparison with the HHV-6A strain U1102 (Uganda), GS (United States), and AJ (Gambia) genomes (top and middle [two]) and the ciHHV-6A genome in European LEI-1501 (bottom). The color key matches that of the network in Fig. 3D. The x axes of all the graphs show a single copy of DR1 and DR6, followed by genes found in the U region.