Fig. 6From: Comparative features of infections of two Massachusetts (Mass) infectious bronchitis virus (IBV) variants isolated from Western Canadian layer flocksMass-type IBV isolates recovered from Western Canadian layer flocks increase macrophage numbers in trachea. The representative images of trachea stained for IBV antigens and macrophages (a) and quantitative data for IBV antigens (b), macrophages (c) and IBV antigen positive macrophages (d) at 4 dpi are depicted. The error bars represent the ± SEM. Statistical significance: *p < 0.05, **p < 0.01, ***p < 0.001Back to article page