Figure 8

Viral genotypes resulting from transcription of integrated, mismatched viral genome. Following integration as a mismatched base, the mutation in the PBS is corrected by the host proofreading mechanism to either a matched, suboptimal thymine/adenine (T/A); a matched, optimal cytosine/guanine (C/G); or remains uncorrected as a mixed base cytosine/adenine (C/A). The resulting progeny virus produced from each of these scenarios is depicted: the matched C/G will produce virus with an optimal (C) PBS, while the mixed base (C/A), and the suboptimal (T/A) will both produce virus with a suboptimal uracil (U) at position 860 within the PBS. Virions bearing the suboptimal U in the PBS will repeat the entire cycle and integrate as matched, optimal cytosine/guanine (C/G), matched suboptimal (T/A), or mismatched as seen previously. Virions with the corrected C in the primer binding site will subsequently only integrate as a matched C/G, and will only produce progeny virus with the corrected PBS.