FIG. 9.

Replication of viable WN 3′SL mutant viruses in BHK cells. Plaque titers were determined for pools of viruses derived by transfection of BHK cells in Vero cells; these viruses were used to infect confluent monolayers of BHK cells at an MOI of 0.01. Plaque titers were determined for aliquots of the medium on infected cells on Vero cells on the days shown after infection. Results for wt WN virus strain 956 and WNmutA1L, WNmutA3, WNmutC1, WNmutE, and WNmutF1 viruses are shown. Solid circles and dashed line, wt WN virus; solid squares, WNmutC1 virus; solid triangles, WNmutE virus; open circles, WNmutF1 virus; open triangles, WNmutA3 virus; open squares, WNmutA1L virus.