Protein synthesis in DF-1 cells infected with recombinant viruses. A. Western blot of NP and GAPDH proteins from rNA-1(−), rNA-1, and NA-1 virus-infected cells. B. Ratios of quantified NP protein to GAPDH protein levels from the rNA-1(−), rNA-1, and NA-1 strains (*, p < 0.05). Each bar shows the mean and standard error of the mean of triplicate samples.