| 摘要 |
An optimum time has been discovered for obtaining porcine oocytes with improved developmental competence. Harvested oocytes are matured by culturing in vitro, and then activated ~42-46 hours after beginning of the culture period. Alternatively, ovulation is induced in a donor female using a gonadotrophic hormone (optionally monitored by ultrasonography), maturation is allowed to proceed in vivo, and then the harvested oocyte is activated ~44-48 hours after inducing ovulation. Outside the optimal time frame, the ability of the oocytes to undergo parthenogenetic activation declines markedly. These methods overcome problems encountered with previous protocols for nuclear transfer and assisted reproduction in the pig. |
