FIG. 2.

Env quasispecies complexity in 12 primary infection subjects from Zambia. A neighbor-joining tree of SGA-derived full-length env sequences is shown. Brackets encompass sequences from each study subject, as indicated. Asterisks at nodes indicate 90% or higher bootstrap values (shown only on branches whose length exceeds 0.003 substitutions per site). The scale bar represents 0.01 nucleotide substitutions per site. 98ZA502, DU151, DU422, TV012, TV002, SK144B1, and BWMC168 represent subtype C reference sequences. ZM231F falls outside all known group M subtypes and thus remains unclassified.