Fig. 4. Effects of Nm23-H1 expression on progesterone-induced p42 MAPK phosphorylation (A) and Mos accumulation (B) and on Mos-induced p42 MAPK phosphorylation (C). p42 MAPK (A) and Mos (B) immunoblots for progesterone-treated oocytes are shown. Oocytes were microinjected with 50 ng of mRNA encoding Nm23-H1 or Nm23-H1F or with water and incubated for 20 or 24 h. Oocytes were then incubated with progesterone (0.1 µg/ml) for the lengths of time indicated. Five oocytes were randomly collected, pooled, and lysed for each time point. The upper bands in A represent phosphorylated p42 MAPK. The first two lanes in A and B are samples of immature oocytes (-) and mature oocytes (+) run as standards. The remaining lanes are samples of five oocytes collected at various times after progesterone treatment and then pooled and lysed. C, p42 MAPK immunoblots of Mos-injected oocytes. Oocytes were microinjected with 50 ng of mRNA encoding Nm23-H1 or Nm23-H1F or with water and incubated for 20 or 24 h. Oocytes were then microinjected with purified recombinant Mos protein (final concentration, 180 nM) and incubated for the lengths of time indicated. Samples of five oocytes were pooled and lysed for each time point.