Fig. 8. Binding of GST Mu and Pi peptides to oocyte ZP. Oocytes were incubated with GST PiN and MuN peptides (10 µg/ml) for 30 minutes at 37°C followed by treatment with rabbit anti-GST PiN and MuN antibodies (1:100) and subsequently stained with anti-rabbit IgG (1:200) conjugated to FITC. This figure shows fluorescence photomicrograph of oocytes incubated with (A) total sperm plasma membrane GSTs. (B) GST PiN peptide. (C) GST MuN peptide. (D) Four-cell embryo incubated with total plasma membrane GSTs. (E-H) Phase-contrast photomicrographs of A-D, respectively. (I) A control oocyte treated with unrelated peptide (tritrypticin-VRRFPWWWPFLRR). (J) Phase contrast of I. Inner cytoplasmic masses (i) have been pushed out to rule out any background staining. Z, ZP. Bars, 100 µm.