FIG. 2.

Phylogenetic tree generated by maximum parsimony analysis of nucleotide sequences from the entire genome of 11 DEN-2 viruses, sequences of previously published strains and representatives of DEN-1, -3, and -4. Viruses are listed by strain number (Table 1). Branch lengths (proportional to the bar, which equals 1,000) represent the number of nucleotide substitutions between the viruses over the 10,724 nt of the genome used for comparison. Bootstrap values are shown in italics above the branches.