First Cloned Mammal A group of British researchers, headed by Dr. Ian Wilmut, an embryologist at the Roslin Institute in Edinburgh, created a lamb using DNA from an adult sheep. Dr. Wilmut took a mammary cell from an adult sheep and prepared its DNA so it would be accepted by an egg from another sheep. He then removed the egg's own DNA, replacing it with the DNA from the adult sheep by fusing the egg with the adult cell. The fused cells, carrying the adult DNA, began to grow and divide, just like a perfectly normal fertilized egg, to form an embryo. The embryo was implanted into another ewe and Dolly was born. DNA tests show that Dolly is the clone of the adult ewe who supplied her DNA. "What this will mostly be used for is to produce more health-care products," says Wilmut. "It will enable us to study genetic diseases for which there is presently no cure and track down the mechanisms that are involved. The next step is to use the cells in culture in the lab and target genetic changes into that culture."