At the Roslin Institute, Wilmut and his colleagues at the U.K. biotechnology company PPL Therapeutics demonstrated for the first time with the birth of Dolly that the nucleus of an adult cell can be transferred to an empty egg to create cloned offspring. PPL holds an exclusive license for the cloning technology. Since then, cloning technology has advanced so quickly in animals it has become almost commonplace. A virtual barnyard of animals have been cloned, such as cows, goats and pigs. Some cloned animals have been endowed with an extra gene, marking a significant step toward a longstanding goal of creating animals that produce medically useful drugs in their milk or blood.
Scientists also use cloning to test how identical cells react to different substances.
The Geron-Roslin scientists hope that they can grow replacement cells that are genetically identical to those in the sick organ, to be injected into the ailing patient. Geron continues to seek corporate partners to further develop its transplant technology and is in talks with several big drugmakers.