FIG. 1.

Phylogenies of human enterovirus 71 (EV-71) VP1 genes. The maximum-likelihood phylogenetic trees of EV-71 VP1 genes from genogroup B and C are shown. Complete VP1 genes of genogroup B (n = 283) and C (n = 344) with known sampling dates (1972 to 2008) were used. Each genogroup is classified into five subgenogroups, denoted B1 to B5 and C1 to C5, respectively. The trees are midpoint rooted, and significant bootstrap support values (≥80%; 1,000 bootstrap replicates) are indicated by asterisks at major nodes. Scale bars signify a genetic distance of 0.02 nucleotide substitutions per site. For clarity, the year of isolation of each sequence is not shown in this figure but is listed in Fig. S1 and S2 in the supplemental material. Several C3- and C4-like isolates are also shown at the base of the C3 and C4 clusters, respectively.