Bisphenol-A (BPA) affects reproductive formation across generations in mice

To understand effects of Bisphenol-A (BPA) exposure on the reproductive organ across generations, we analyzed morphology of the uterus and ovary, and the methylation pattern of HOXA10 gene of the 2(nd) generation. Pregnant mice (F0) were treated with sc injection of BPA in sesame oil at various doses of 0-1,000 mg/kg Bwt on days 12-16 of gestation. Their offspring (F1) were bred by foster mice, and the offspring (F2) from F1 mice were prepared. That is, F1 mice experienced in utero BPA exposure during the developmental period of reproductive organs, while F2 mice did not at all. Using these F2 mice, the present study was carried out. Comparing to the control, the body weights in BPA exposure groups were significantly increased. Correlating with the increase of body weight, the relative weights of the ovary and uterus in each group were decreased. The histological analysis revealed expansion or emphraxis of the uterine lumen and partial loss of the uterine epithelium. Unmethylation of HOXA10 gene in the uterus was observed in the intron region. The present study suggested that BPA exposure to F0 mice could affect reproductive organ of F2 mice who were not exposed to BPA.