Figure 3.

Schematic of SOS virus evolution. A. The wt Env protein and the SOS mutant are shown. SOS Env formed the starting point for evolution of the revertant virus in culture X at week 7, and this culture was split in two and cultured up to week 15 (X3 and X4; see the text). B. Virus evolution starting with the SOS-X molecular clone (A501C T605C L593Q T719I). Nine independent cultures were followed over time.