Fig. 3. Effects of anti-CD9 mAb added before zona removal. (A) 6 integrin subunit distribution of a control zona pellucida-free egg (a) or of eggs pretreated before zona pellucida removal with the mAb SYB-1 directed against CD9 (b,c). At 50 µg/ml, the patches were smaller (b) whereas at 100 µg/ml (c) the 6 distribution was similar to that of ZP intact oocytes (d). Bar, 50 µm. (B) Effect of mAb against CD9 on gamete fusion. Eggs pretreated with 100 µg/ml of SYB-1 prior to zona pellucida removal were tested in the presence of 50 µg/ml of SYB-1 for 18 hours. *The number of fused spermatozoa was significantly reduced (P<0.001). Lines represent the mean ± s.d. from three different experiments. The number of eggs used in each condition is given above. (C) CD151 (e) and CD81(f) tetraspanins distribution on eggs pretreated before zona pellucida removal with the mAb SYB-1 (100 µg/ml). (D) 6 integrin subunit distribution on eggs pretreated before zona pellucida removal with the mAb anti-CD81, Z81 (100 µg/ml).