Figure 2.

Effect of an anti-CD9 mAb on mouse sperm–egg binding and fusion. Zonae pellucidae from mature mouse eggs were removed by brief incubation in chymotrypsin followed by mechanical shearing. Zona-free eggs were incubated with the indicated concentrations of the anti-CD9 mAb (solid bars) or with 100 μg/ml of the non-function-blocking anti-α6 mAb, J1B5 (hatched bars), or anti-MLV mAb (shaded bars) in M199 medium. Eggs were processed and analyzed for sperm–egg binding (A) and fusion (B). Data represent the mean ± SE from three pooled experiments. Values with different letters are statistically different (P < 0.05). Sperm binding was inhibited similarly when eggs were pretreated with JF9 and then washed before sperm binding (data not shown).