Recombinant DNA technology

Recombinant DNA technology has dramatically impacted numerous fields – from medicine to agriculture. Recombinant DNA technologies have helped create genetically altered plants, which can withstand harsher environmental conditions and pesticides to yield larger crops. They have also helped produce advances in medicine, such as treatments for cancer, production of insulin and other recombinant proteins, and even vaccines. One interesting use of recombinant DNA technology, is in the field of animal husbandry. Recombinant DNA technologies pertaining to animal husbandry have led to the development of transgenic animals and clones, including the first successfully cloned animal, Dolly the sheep. Transgenic animal models differ from cloned animal models. Transgenic animal models can be created in 3 steps:

1) Healthy eggs from a female donor are removed and fertilized in vitro.

2) Desired genes from another species are identified, isolated, and cloned

3) The cloned genes are directly injected into the eggs and then surgically implanted into the female host. Cloning is a different process, which can be described in the following steps:

1) A differentiated cell has its nucleus removed as the source of DNA for the cloned animal.

2) An egg cell from a similar species is obtained and anucleated.

3) The two egg cells are fused together by an electric current to form a diploid cell, which begins normal cell division.

4) The developing embryo is placed in a surrogate mother, which then undergoes a normal pregnancy. Cloning and the creation of transgenic animal models have had a significant impact in both farming and medicine. The use of transgenic mice to study disease and in research has led to a better understanding and treatments for many diseases.

Adapted from: Moulton, G. (2004). The Complete Idiot's Guide to Biology. New York, NY: Penguin Group.