Figure 2

Cartoon representation of SIVtat1ex fitness in vivo. In the presence of specific CTL response against these epitope(s), cells expressing two-exon Tat are eliminated and SIVtat1ex becomes relatively more fit, albeit at lower level overall. The single exon Tat genome is represented by a pink bar with a jagged edge; the two-exon Tat genome is depicted by a green rectangle. Viruses are illustrated as hexagons with inner ovals.