Representative TUNEL assay images of COCs after exposure to ACR.

<p>(A) COCs were treated with 0 μM (a1, a2, a3), 5 μM (b1, b2, b3), 10 μM (c1, c2, c3) and 20 μM (d1, d2, d3) of ACR. Apoptotic cells are displayed in red (a1, b1, c1, d1) and nucleuses are displayed in blue (a2, b2, c2, d2). a3, b3, c3, d3 is the merge of (a1, a2), (b1, b2), (c1, c2), (d1, d2), respectively. Bar = 25 μm. (B) The percentage of TUNEL positive cumulus cells in 0, 5, 10 and 20 μM ACR-treated group. Data is expressed as the mean ± SD of three separate experiments. * indicates P < 0.05 vs. control, *** indicates P < 0.001 vs. Control.