Q.Explain, how transgenic animals are used for producing biological products?

Transgenic animals carrying a foreign gene for a useful protein can be engineered to secrete that protein (commonly into milk), from which it is purified and used as a biological/pharmaceutical product.

Transgenic animals - animals whose DNA has been manipulated to possess and express an extra (foreign) gene - are used as 'bioreactors' to produce biological products. A gene of interest (usually a human gene coding for a useful protein) is introduced along with regulatory DNA sequences that direct its expression specifically into the mammary gland, so the protein is secreted in the animal's milk. The milk can then be collected and the desired protein purified from it in large quantities, avoiding the need for large-scale cell-culture-based production. A well-known example is transgenic sheep and cows engineered to produce human proteins such as alpha-1-antitrypsin (used to treat emphysema) or blood-clottin …