PCV2-induced apoptosis.

<p>(A) Cells infected with PCV2 (MOI = 1) were fixed for the TUNEL assay at 72 hpi and immunostained for viral proteins. Apoptotic cells (green), PCV2 Cap proteins (red), CSFV E2 proteins (blue) and nuclei (grey) are shown. (B) Statistical analysis of PCV2-induced apoptosis. Total numbers of TUNEL-positive, PCV2-positive and TUNEL-PCV2 dual-positive cells were counted, and proportions of each type of cells in all labeled (TUNEL or immunostained) cells were calculated in four random fields. (C and D) Cells inoculated with PCV2 of different MOIs were determined by TUNEL assay (C) and measurement of luminescent caspase–3/7 activities (D). The red bar in the merged image indicates 10 μm. Data are represented as means ± SD (n = 3 or more; ns, <i>P</i> > 0.05).