The ewe's cells gave rise to Dolly , the first mammal to be cloned from an adult. Our announcement of Dolly's birth in February 1997 attracted enormous press interest , perhaps because Dolly drew attention to the theoretical possibility of cloning humans. This is an outcome I hope never comes to pass. But the ability to make clones from cultured cells derived from easily obtained tissue should bring numerous practical benefits in animal husbandry and medical science, as well as answer critical biological questions. How to Clone Cloning is based on nuclear transfer , the same technique scientists have used for some years to copy animals from embryonic cells.
Nuclear transfer involves the use of two cells.
The recipient cell is normally an unfertilized egg taken from an animal soon after ovulation. Such eggs are poised to begin developing once they are appropriately stimulated. The donor cell is the one to be copied. Then, typically, the donor cell, complete with its nucleus, is fused with the recipient egg. In our experiments with cultured cells, we took special measures to make the donor and recipient cells compatible.