Figure 2. A) Maximum-likelihood phylogenetic tree of 264 complete envelope gene sequences of dengue virus serotype 3 (DENV-3). The different genotypes of DENV-3 and the isolates from Bhutan (red) are indicated. Scale bar indicates number of substitutions per site. B) Magnification of the part of the phylogeny where the Bhutan sequences (red) fall. The tree is midpoint rooted for clarity only, and all horizontal branch lengths are drawn to a scale of nucleotide substitutions per site. Bootstrap support values are shown for key nodes only.