On 5 July 1996 a sheep named Dolly was born in Scotland, the result of the transfer of the nucleus of an adult mammary tissue cell to the enucleated egg cell of an unrelated sheep, and gestation in a third, surrogate mother sheep. Although for the past ten years scientists have routinely cloned sheep and cows from embryo cells, this was the first cloning experiment that apparently succeeded using the nucleus of an adult cell.