Processes used to produce transgenic species
Transgenic species are groups of organisms that contain genes from other species.
Transgenic animal species are produced by two main methods: the transgene ("two separately cloned genes are spliced together, one gene contains the coding sequence for the protein of interest and the other controls the tissue in which the animal protein will be expressed") can be microinjected in or created by using embryonic stem cells. The microinjection method involves the injection of DNA into the pronuclei of a fertilised egg, which is cultured in a laboratory. The modified eggs are then implanted into a female where they develop and are born. Embryonic stem cells can be cultured and the transgene added. It then begins dividing, and is incorporated into a new blastocyst which is then implanted into a female to develop and is born.
Examples of transgenic species are commercial crops, such as corn, potatoes and cotton that contain the gene for the toxin from the bacterium B.
thuringiensis. This toxin protects the crops against damaging pests however does not harm their natural predators. Recent work has involved the production of transgenic cows and goats. The cloned transgenic goats Mira, Mira and Mira produce milk that contains an anti-clotting protein that can be isolated and used in patients undergoing heart surgery. Transgenic hamsters have been used to produce the hormone that stimulates ovulation, Recombinant Follicle Stimulating Hormone, and pharmaceutical drugs such as 'Puregon' use such products, which is used in the treatment of infertility in women.
Reasons for the production of transgenic species
Therapeutic treatment of humans with certain protein deficiencies, animals are modified to produce specific proteins, usually in their milk.
Plants altered to increase their nutritional value and content;
Commercial crops modified to become resistant to insects, pesticides, herbicides, virus'...