Pol β-deficient mouse ovarian function and impaired BER lead to ovarian aging. (H) Scatter graphs show a lower number of oocytes yield in Pol β+/- mice compared to wt mice, (Mice aged 6-8 weeks; n =20 per group; n stands for the number of mice, ***P < 0.001, Student’s t test). (I) Pol β+/- mice also showed significantly lower meiosis II (MII) oocyte yield per female than wt mice (Mice aged 6-8 weeks; n =8 per group; n stands for the number of mice, ***P<0.001, Student’s t test). (J) Reduced litter size in Pol β+/- mice (Mice aged 6-8 weeks, n =6 per group; n stands for the number of mice, ***P < 0.001, Student’s t test). (K) In newborn mice, Pol β+/- offspring had lower mean serum AMH concentrations than wt mice (Mice aged 2 weeks, n =5 per group; n stands for the number of mice, *P < 0.05, Student’s t test). (L) Compared to wt (6-8 weeks), Pol β+/- (6-8 weeks) and wt (8 months) oocytes after treatment with different H2O2 concentrations at 30 minutes exhibited different survival (n stands for the number of oocytes, ***P<0.001, **P<0.01, Student’s t test). (M) Compared to wt (6-8 weeks), Pol β+/- (6-8 weeks) and wt (8 months) oocytes after treatment with same H2O2 concentration exhibited different survival (n stands for the number of oocytes, ***P<0.001, ***P<0.001, Student’s t test).