Transgenic animal
- A transgenic animal is one whose genome has been changed to carry genes from other species.
- They are produced for the following reasons:
a) Some transgenic animals are produced for specific economic traits. For example, transgenic cattle were created to produce milk containing particular human proteins, which may help in the treatment of human emphysema.
b) Other transgenic animals are produced as disease models (animals genetically manipulated to exhibit disease symptoms so that effective treatment can be studied).
How are transgenic animals produced?
The insertion of a foreign gene (transgene) into an animal is successful only if the gene is inherited by offspring. The success rate for transgenesis is very low and successful transgenic animals need to be cloned or mated.
To date, there are three basic methods of producing transgenic animals:
- DNA microinjection
- Retrovirus-mediated gene transfer
- Embryonic stem cell-mediated gene transfer.
How do transgenic animals contribute to human welfare?
- Agricultural Applications
a) Breeding: Transgenesis will allow larger herds with specific traits.
b) Quality: Scientists can improve the size of livestock genetically.
c) Disease resistance: Disease-resistant livestock is not a reality just yet.
2. Medical Applications
a) xeno-transplantation: Transplant organs may soon come from transgenic animals.
b) Nutritional supplements and pharmaceuticals: Milk-producing transgenic animals are especially useful for medicines.
c) Human gene therapy: A transgenic cow exists that produces a substance to help human red cells grow.
3. Industrial Applications: Uses in industry include material fabrication and safety tests of chemicals.
