We investigated the fertilization and developmental ability of superovulated eggs obtained from adult Wistar-Imamichi (WI) rats, by using pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) treatment. Female WI rats, 11-13 weeks of age, were divided into four groups by estrous stage (metestrus [ME], diestrus [DE], proestrus [PE], or estrus [E]). PMSG (150 IU/kg) and h...