FIG 8.

ΔFP-GPC rCan undergoes I427F reversion upon serial passage, whereas K33S/A168T/ΔFP rCan does not. ΔFP-GPC rCan (A) and K33S/A168T/ΔFP rCan (B) were serially passaged 10 times in the presence or absence of 1 mM AmCl. Virion RNA was prepared after 2, 5, and 10 passages, and the RT-PCR product of the GPC open reading frame was subjected to Sanger sequencing. The chromatograms reveal the emergence of the I427F mutation (ATT to TTT) in the former but not latter virus. No additional changes in GPC were noted.