Fig. 3.

Histogram showing the mean percentages of putatively polyploid nuclei (with multiple hybridization signals) in mouse ovaries. (a) Ovarian follicles from non-pregnant females of different ages (the number of nuclei with hybridization signals analysed are shown above the bars). (b) Ovarian follicles at different stages (stages 6a and 6b are antral follicles; others are pre-antral follicles). A total of 8920 nuclei with hybridization signals were analysed from non-pregnant mice (ranging from 125 for stage 5 follicles to 5917 for stage 6a); 6236 positive nuclei were scored from non-pregnant mice (ranging from 299 for stages 2 and 3 to 2896 for stage 6a). (c) Ovarian follicles and corpora lutea from pregnant and non-pregnant mice. (The mean and standard error are shown for percentages calculated separately for each follicle or corpus luteum and the numbers of follicles and corpora lutea analysed are shown above the bars.) Abbreviations: Non-preg, non-pregnant; PreA, pre-antral follicles; A, antral follicles; NM, female not housed with male; 0.5, 3.5 and 7.5 indicate number of days post-coitum. No embryos were found in three mice, 3 days after finding vaginal plugs (3.5 non-pregnant group).