Tracy, a transgenic sheep, Scotland, 1999
‘Tracy’ the sheep (1990-97) was genetically modified to produce a human protein, alpha antitrypsin, in her milk. The protein is being clinically tested by PPL Therapeutics, who also donated Tracy to the Science Museum, with the aim of finding a treatment for the symptoms of cystic fibrosis. Tracy was born in 1990 after human DNA was inserted into fertilised sheep embryos at the Roslin Institute near Edinburgh, Scotland. In an attempt to reproduce animals such as Tracy, the Roslin Institute later cloned Dolly the sheep.
Related Themes and Topics
DNA stores the information, or blueprints, of every cell and is located in the genes. It is made up of two strands which form a double helix that is linked by hydrogen bonds. It was first described in 1953 by Francis Crick and James Watson.
Glossary: cystic fibrosis
A genetic disorder that affects the internal organs, especially the lungs and digestive system, by clogging them with thick sticky mucus. This makes it hard to breathe and digest food. Sufferers are usually treated with physiotherapy, exercise and medication.
Proteins are large organic compounds made of amino acids. They are essential to all living cells and organisms.
The development of artificial replacement limbs, organs and tissues. It also refers to the use of plants in controlling erosion and in landscape restoration.