Fig. 4. Cyclin B1 does not require the MAPK cascade pathway to induce GVBD. Oocytes injected with recombinant GST-cyclin B1 (1 mg/ml) in absence (B1) or presence (B1+CHX) of cycloheximide were homogenized 2 hours after they underwent GVBD and analyzed by immunoblot for diphosphorylated MAPK and Mos. Non-injected oocytes stimulated with progesterone (control M) or not (stage VI) are shown as control. Groups of three oocytes were homogenized and the equivalent of one oocyte was loaded per lane.