Figure 3

Growth curve of mutant virus in CEF. The cell monolayers were infected with mutant viruses at an MOI of 1 for 72 h, and TCID₅₀ virus titers were measured in the supernatants at the time points indicated. The error bars represent SD of the means from three independent experiments. The statistical differences in the growth properties between the wild-type virus and mutant viruses was assessed through a Mann–Whitney test (*p < 0.05).