FIG. 1.

Phylogenetic trees of HIV-1 env C2-V5 DNA and RNA nucleotide sequences. Phylogenetic analysis of all viral sequences (253 from proviral DNA and 253 from plasma RNA) was performed by feeding the Kimura two-parameter distance matrix into the neighbor-joining tree. Distinct clusters of viral sequences corresponding to each subject were found, indicating the absence of cross-contamination. The HIV-1 MN strain was used as prototype of clade-B env sequences. Branch lengths are drawn to scale. Bootstrap proportions are shown in the appropriate branch point.