FIG. 1.

Behavior of FMDV mutants with the replacements G62S and M296I in 3D. (A) Scheme of the passages of pMT28-3D(G62S) and pMT28-3D(G62S-M296I) in BHK-21 cells. Filled squares represent the initial RNA transcript used for two transfections (T). Progeny viral populations are depicted as filled squares, and the letter p stands for passage number. Passages were carried out in the absence or presence of R, as explained in the text. Below each viral population, the dominant amino acids at positions 62 (G or S) and 296 (M or I) are indicated (an equality sign indicates equal proportions of the two amino acids, a greater-than sign indicates about 70% of the amino acid written first, and S-I means a double-mutant polymerase with S62 and I296). The mutant dominances upon transfection and passages in the presence of R are given in parentheses. (B) Infectious progeny production by pMT28-3D (wild type) and pMT28 expressing mutant polymerases in the absence (empty bars) or presence of 200, 400, or 800 μM R (increasingly darker gray bars) at 10 and 24 h postinfection. (C) Ratio of infectious progeny production in the absence of R relative to the presence of 200, 400, and 800 μM R (increasingly darker gray bars). Symbols are as in panel B. Procedures are described in Materials and Methods.