FIG. 2.

Phylogenetic analysis of env quasispecies from the 4 monkeys infected with SIVmac251. The maximum-likelihood tree is rooted on the consensus of the inoculum (blue circles). Sequences from each monkey clustered together and are represented by similarly colored symbols, as indicated. The transmitted viruses at peak viremia in each monkey are represented by open circles, viruses from 5 to 8 months (Mo) p.i. by open triangles, and quasispecies from 16 months p.i. by open squares and 22 months p.i. by closed squares. The scale bar indicates a genetic distance of 0.001 (1 nucleotide difference per 1,000 sites) in the phylogram.