FIG. 2.

Activation of Plx1 during oocyte maturation. Oocytes were incubated in the presence of progesterone (3.2 μM), and groups of 10 oocytes were frozen at the times indicated. (A) Extracts were prepared, and histone H1 kinase (▪) and Plx1 (□) activities were determined. (Inset) The time of GVBD was established by examining oocytes for white spot formation with a dissecting microscope. (B) Samples of extracts were subjected to immunoblotting with anti-Plx1 or anti-Cdc25C antibodies (upper and lower panels, respectively). Molecular masses (in kilodaltons) are indicated on the left.