Figure 3.

Estimated number of amino acid substitutions at each amino acid site of the V3 region observed for the six patients. In estimating the number of amino acid substitutions for each patient, we inferred the ancestral amino acid sequences at all branching points from the phylogenetic tree. Amino acid positions with one or two red asterisks are the sites where amino acid substitutions dominantly occurred with statistical significance at the 5% or 1% level, respectively. Horizontal bars show the amino acid stretches with which monoclonal antibodies interact. #: Amino acid sites responsible for antigenic variation. ∧, Amino acid sites responsible for cell tropism or syncytium-inducing phenotype.