FIG 8.

Dendrogram of genetic distances among HSV-1 genomes reveals broad geographic clustering. The multiple-genome alignment of 26 strains of HSV-1 was used to generate a genetic distance matrix under a maximum composite likelihood substitution model. A dendrogram was then calculated using UPGMA in MEGA, with 1,000 bootstrap replicates. Numbers indicate branch confidence. The majority of strains cluster into four groupings that reflect their geographic origins, with the large collection of African strains splitting into two groups or, potentially, three groups (i.e., E03 as a third singleton group).