Fig. 7. Ovaries from control and Ercc1-deficient mice. (A) 8-day wild type, (B) 8-day Ercc1 null, (C) 14-day wild type, (D) 14-day Ercc1 null, (E) 6-week wild type, (F) 6-week transgene-positive Ercc1 null mice. Note that numerous primary follicles (arrows) are present in the wild-type samples (A,C,E), but appear to be absent from the ovaries in both types of Ercc1-deficient sample (B,D,F). Organisation of granulosa cells (gc) around oocytes occurred in both wild-type and Ercc1-deficient ovaries. By day 14 some follicles had matured sufficiently to form an antrum (A) in both wild-type and Ercc1-null ovaries (C,D). The development of the most mature follicles appeared less advanced in the null animals on day 14 and in the adult transgene-positive females compared with their wild-type littermates. Oocytes with an abnormal appearance were frequently observed in both types of Ercc1-deficient ovary (^*). Scale bar, 100 µm.