Fig. 2.

IBV infections resulted in significant increase in apoptosis of chicken embryo kidney (CEK) cells and chicken embryo tracheal organ cultures (TOCs). CEK cells and TOCs were infected with IBV strains 885, QX, M41 or mock infected. At 24 and 48 hpi, cell metabolic activity of CEK cells was evaluated by (A) MTT assay and percent of apoptosis by (B) Annexin V binding, respectively. Total apoptotic cells in TOCs were evaluated by (C) TUNEL assay. Virus production in the (D) CEK cells and (E) TOC supernatants were determined in chicken embryo TOCs at designated time points after infection. Data represents mean of triplicate wells, with error bar showing standard error. Different letters indicate that the differences between groups at that time point are significant (p<0.05).