Transgenic mice have become the stock-in-trade of basic biomedical research since their creation in the early 1980s. The techniques used to insert human genes into non-human species that were refined in rodents are now being applied to a menagerie of other mammals. These chimeric goats, pigs, sheep, cows, and rabbits are essentially living bioreactors: When a gene inserted into their DNA is specifically activated in mammary gland cells, the desired human protein is secreted into the animal's milk. The protein is then isolated and purified. Academic, government, and industry researchers in the United States and Europe have been developing transgenic animals in hopes of producing safer and cheaper pharmaceuticals.
|BUNNIES AND BULLS: Netherlands-based Pharming BV uses cattle and rabbits for its transgenic products, notes Gerard van Beynum.|