Effect of TCS exposure on mitochondrion-mediated apoptosis of porcine COCs: (a) The mRNA levels of mitochondrion-mediated apoptosis genes (Bax, Bcl-xl, and caspase-3) were investigated in TCS-treated COCs using RT-PCR; Gapdh served as an internal control. (b) Western blotting results for AIF, Cyto C, cleaved caspase-3, and cleaved PARP1 in porcine COCs. Relative fold changes in the levels of proteins related to mitochondrial apoptosis were obtained after normalization of signals to β-actin levels. Histograms represent the values of densitometry analysis obtained using ImageJ software. Data in the bar graph are presented as the mean ± SEM of three independent experiments (30 COCs). Differences were considered significant at * p < 0.05, ** p < 0.01, and *** p < 0.001 compared with the non-treated group.