Fig. 4.

Histopathologic changes (A) and mean lesion scores (B) in the trachea, lung, and kidney at 9 dpc in chickens experimentally infected with rYN, rYN-S-aYN, rYN-5a-aYN, or the control. Black arrows indicate lesions detected in the tissue. Scale bar = 100 μm. The indications for the scores were as follows: 0 = no microscopic lesions, 1–3 = mild lesions, 4–6 = moderate lesions, 7–10 = severe and extensive lesions (n = 2 × 3). Data were statistically evaluated by one-way ANOVA test adjusted for post-hoc analysis, followed by Bonferroni's multiple comparison tests. Statistical significance was considered as follows: significant at p < 0.05 (*), highly significant at p < 0.01 (**), and very highly significant at p < 0.001 (***).