An adult cell from the mammary gland of a Finn - Dorset ewe acted as the nuclear donor; it was fused with an enucleated egg from a Scottish Blackface ewe, which acted as the cytoplasmic (or egg) donor.
Wilmut and his colleagues transplanted a nucleus from a mammary gland cell of a Finn Dorsett sheep into the enucleated egg of a Scottish blackface ewe.