Much like corn crops are being used to produce bio fuels, farmers may soon be putting their cows, sheep and chickens to new unexpected uses.
How it is done
Since the human gene will be present throughout the cow’s whole body, scientists needed to find a way to restrict the expression of the gene to the cow’s udder. After all, we do not want the human protein to be produced in the cow’s heart or brain, where it may do harm.
The key to getting a cow or a chicken to produce a specific protein is to introduce the gene that codes for that particular protein into the cow's genome. Put another way, scientists have to smuggle the recipe for making the medicine into the animal’s body.
Medicines made in this way
Once the genetic manipulation has been done successfully, all that remains is to milk the cows and extract the required proteins.
Genetic Science Learning Centre (University of Utah)
Gene therapy – what you need to know