Successful pregnancy after transfer of rabbit blastocysts grown in vitro from single-cell zygotes.

To establish successful pregnancy in rabbits after the transfer of blastocysts cultured in vitro for 72 h, pregnancy rates were compared according to synchronization methods of recipient and embryo transfer sites. Also, the effect of RDH (1:1:1 mixture of RPMI, DMEM and Ham's F10) medium with additives such as BSA and taurine was evaluated for developmental capacity and cell number. Developmental capacity and cell number were considered important for implantation. When we evaluated the relative survival of rabbit one-cell embryos after culture in Ham's F10, in RD or in RDH for 72 h, embryos cultured in RDH and RD developed much better than in Ham's F10. When the effects of BSA and taurine in RDH medium were tested for rabbit embryo development, BSA or taurine promoted transition to the blastocyst stage and increased cell numbers of cultured embryos in RDH medium. The BSA and taurine together in RDH medium had a synergistic effect on embryo development. By transferring cultured blastocysts to the oviduct of the recipient doe synchronized one day behind the donor, live-born pups were obtained successfully. These results demonstrated that rabbit blastocysts can develop to normal pups after in vitro culture and embryo transfer.