Figure 3. Effect of AA supplementation on sperm binding to the zona pellucida of porcine in vitro aged oocytes after in vitro fertilization. (A) Representative fluorescence images of sperm binding to the surface of the zona pellucida surrounding oocytes staining with Hoechst 33342 in each group. Scale-bar=100 μm. (B) Number of sperm binding to the surface of the zona pellucida surrounding oocytes in each group. The number of oocytes examined in each group is shown by the bars. Statistically significant differences are indicated by different letters (p<0.05).