Abstract
This study was conducted to examine the possibility of nuclear transplantation using the bovine oocytes matured in vitro. Sixteen-cell stage embryos (fresh, frozen or embryos developed from the oocytes matured and fertilized in vitro) were designated to donor cells. The follicular oocytes matured in vitro were used as enucleated recipient oocytes. The enucleated oocytes were fused with a blastomere from donor embryos by electrofusion. Most recipient oocytes (325/417, 78%) fused with donor cells. The reconstituted eggs developed to 2-cell stage when cultured on a layer of cumulus cells (187, 58%). Out of the 325 reconstituted eggs, 35(11%) developed into morulae and 9 (3%) into blastocysts stage respectively. Eighteen morula or blastocyst stage embryos were transferred nonsurgically to 9 recipient cows into 1-3 embryos per recipient. Two recipients were confirmed pregnant. One of recipients produced a live offspring resulting from a fresh donor blastomere. The present study showed that in vitro matured oocytes can be used as recipient cytoplasm.
