FIG. 4.

Dynamic features of the selective forces on the complete HIV-1 C2-V5 env sequence and on the hypervariable regions V3, V4, and V5 within each subject. Intratime (first sample) and intertime (second and third samples) Ka/Ks values were plotted for the complete C2-V5 sequence of HIV-1 gp120, and the V3, V4, and V5 regions were analyzed separately. The data are shown as positive or negative histograms starting from Ka/Ks = 1. Sample points are indicated by white (first), shaded (second), and black (third) bars.