Fig. 11. Effect of K252a on human ovaries in culture. (A-C) Photomicrographs of human fetal ovaries at 13-weeks gestation. (A) Uncultured ovary containing oogonia. (B) Ovary cultured in the absence of K252a with many oogonia surviving. (C) Ovary cultured in the presence of 100 nM K252a with few oogonia surviving (arrowhead). Scale bars: 20 µm. (D) Density of germ cells in uncultured ovaries, and ovaries cultured in the presence of 0 nM and 100 nM K252a. The number of oogonia was quantified by random stage microscopy. Data are the number of oogonia (mean±s.e.m.) per 121-point grid. A total of 18-42 grids per treatment were counted in each of five experiments. Asterisks indicate significant difference compared with control culture (0 nM K252a), P<0.01.