Analysis of Ovaries and Fertilities in Domestic Animals Affected by the Fukushima Daiichi Nuclear Power Plant Accident

In order to understand the effect of chronic exposure to low-dose-rate radiation on female fertilities and the risk of heritable genetic effects on domestic animals after the Fukushima Daiichi Nuclear Power Plant (FNPP) accident, we assessed the developmental ability of oocytes, and examined the histological characters and structure of ovaries. We showed that potentially viable oocytes could be collected from the ovary of abandoned cattle in the ex-evacuation zone set within a 20-km radius from FNPP, resulting in production of the morphologically normal calves following in vitro culture and embryo transfer. The proliferation of cattle ovarian granulosa cells was confirmed by expression of Ki-67. Apoptosis of oocytes and granulosa cells was few determined by the TUNEL assay. In addition, porcine and inobuta oocytes had the abilities of in vitro maturation. These results suggest that chronic radiation exposure associated with the FNPP accident may have little effect, if any, on the female fertilities of domestic animals.