Lack of effect of maternal age on UV-induced DNA repair in mouse oocytes.

Oocytes at the dictyate stage from young (8-14 weeks) and old (12-15 months) BALB/c mice were manually isolated and UV-irradiated. They were cultured for 1 h in medium containing tritiated thymidine and chased for a further hour in cold thymidine medium before being incubated for 18-20 h in medium with no added thymidine. Oocytes which had developed to metaphase II were analysed following autoradiography. Pooled results from 14 replicate experiments revealed no significant age-related difference between the mean corrected grain count per cell [159.2 +/- 8.5 (86 cells) for young mice and 164.6 +/- 9.8 (70 cells) for the old animals]. Thus in the female mouse the oocyte's capacity to repair UV-induced damage is apparently maintained at a high level throughout reproductive life.