TABLE 1.

Temperature-dependent growth of combination mutants

VirusVirus production (infectious centers/ml)a
37°C28°C
17 h25 h25 h40 h
Wild type3.7 × 1093.2 × 1091.1 × 1087.0 × 108
srf-3 + 42.9 × 1091.3 × 1091.2 × 1082.2 × 108
srf-4 + 51.5 × 1041.5 × 1051.1 × 1071.3 × 107
  • a BHK cells were electroporated with the indicated viral RNA, plated for 2 h at 37°C, and cultured for the indicated times at 28 or 37°C. Progeny virus production was quantitated by using an infectious center assay in BHK cells at 28°C.