NUCLEAR TRANSPLANTATION IN CATTLE - 1ST RESULTS IN BELGIUM

In 1987, Prather et al. have performed the first embryo cloning by nuclear transfer in the bovine species. Since, many researchers tried to develop and to apply the technique. While the enucleation of the recipient oocyte, the injection of the donor blastomere and the fusion procedure are now well controlled; the maturation and the activation as the development and freezing of the cloned embryos need to be more investigated. An increase in embryonic mortality is also observed after transfer in a recipient cow. Nevertheless, 10% of the cloned embryos develop in vitro to the blastocyst stage and give pregnancies after transfer.