Tracy, a transgenic sheep, 1999.
© Science Museum / Science & Society Picture Library
Tracy (1990-1997) was a transgenic ewe that had been genetically modified by the Roslin Institute, near Edinburgh, Scotland, so that her milk produced a human protein called alpha antitrypsin, a potential treatment for the disease cystic fibrosis. The Roslin Institute is of the world's leading centres for animal research. It has internationally recognised programmes on genetics, genomics, early development, reproduction, animal behaviour and welfare, and has pioneered methods for the genetic modification and cloning of farm animals. It produced the first ever cloned animal, known as Dolly the sheep. Dolly was part of a project to reproduce reliably animals with the genes of Tracy.