Fig 2.
IFN induction after infection of TOC from chicken (A) or turkey (B) with wild-type and NS-reassortant FPV HPAIV. Individual TOC were inoculated with 103 FFU of virus (n = 5/virus/time point). TOC supernatants were harvested at different time points, and total bioactive IFN was determined in a VSV CPE inhibition assay (IFN units/ml). Error bars indicate the standard deviations. Different letters indicate statistically significant differences between groups at each time point (P < 0.05; Kruskal-Wallis one-way ANOVA).