Figure 1. . . Maximum clade credibility tree demonstrating the phylogenetic relationships of the 314 dengue virus type 4 (DENV-4) envelope genes (1,485 nt). The major groups (genotypes I–III) are indicated. Branch lengths are scaled in time units; scale bars, representing the chronology of DENV-4 emergence, are color-coded according to the most probable geographic location of the descendent node. Introductions of DENV-4 in Brazil are indicated by numbered circles; numbering follows the temporal order of the mean estimate of divergence time for that particular sequence or clade. In selected nodes, * indicates posterior probability support of 1.00. Panel on right shows a detail of the maximum clade credibility tree (built by using an alignment of 98 DENV-4 full genomes [10,624 nt]) that reveals 3 distinct well-supported introductions of genotype II cluster from neighboring South American countries into Brazil. SE, Southeast; RO, Roraima State; PA, Pará State; AMA, Amazonas State.