Fig 7.

In vitro fusion activity of mutated gH. RK13 cells were cotransfected with expression plasmids for EGFP, gB, gD, gL, and different gH mutants or the empty expression vector (pcDNA3). After 3 days, the number of polykaryocytes in 20 fields of view (A) and the number of nuclei in 20 syncytia per plasmid set (B) were determined. Mean values and standard deviations are indicated. Statistically significant differences from the numbers obtained with wild-type gH are labeled with asterisks (*, P < 0.05; **, P < 0.01).