FIG. 1.

Increased phosphorylation of TFIIIA upon oocyte maturation. Staged oocytes were injected with [γ-³²P]ATP and kept at 18°C for 16 h; extract from either whole cells or GVs was then prepared. In the case of mature oocytes, the cells were either injected and then treated with progesterone (lane I_m) or treated with progesterone and injected after GV breakdown (lane M_I). TFIIIA was retrieved from the extracts by immunoprecipitation and analyzed by SDS-polyacrylamide gel electrophoresis, followed by autoradiography. The intensity of the bands was measured with a laser densitometer. Extract from injected stage IV oocytes incubated with protein A-Sepharose (lane C) served as a control for immunoprecipitation.