FIG. 3.

Immunohistochemical staining of the AI virus matrix protein in lung and brain tissues from chickens inoculated with each reassortant virus. Each of three chickens was inoculated intranasally with 10⁶ EID₅₀ of rgCkYK7, rgDkYK-PB2^Ck/NP^Ck, and rgDkYK-NP^Ck, rgDkYK-PB2^Ck, or rgDkYK10, and the lungs (A, C, E, G, and I) and brains (B, D, F, H, and J) were harvested for immunohistochemical staining at 36 hpi from chickens inoculated with rgCkYK7 (A and B) or rgDkYK-PB2^Ck/NP^Ck (C and D) and at 48 hpi from chickens inoculated with rgDkYK-NP^Ck (E and F), rgDkYK-PB2^Ck (G and H), or rgDkYK10 (I and J). Scale bars, 50 μm.