PROGRESS TOWARDS EFFICIENT COMMERCIAL EMBRYO CLONING

Multiplying genetically superior mammalian embryos through nuclear tra nsplantation has considerable potential for improving animal productio n. Today it is possible, at times, to obtain several genetically ident ical offspring from one original embryo. However, the production of a large number of genetically identical animals must be realized before cloning will have a major impact on animal industries. In order to rea lize this potential there must be continued improvements in all facets of the cloning procedure. In the past few years there has been steady progress in improving the nuclear transplantation techniques. These t echniques include oocyte enucleation, blastomere transfer, cell fusion , oocyte activation, preimplantation development and embryo transfer. Owing to the multitude of steps involved in cloning, further advanceme nts in all of these areas will be needed to obtain an efficient system of cloning embryos. Advances are also needed in methods of obtaining large quantities of high quality biological material to be used in the cloning procedure. This is a key factor in making cloning a valuable and cost-effective genetic tool for the livestock industry. The useful ness of embryo cloning will depend on scientific advancements made in the coming years.