كاربرد بيوتكنولوژي در فارمينگ ژني و ايجاد حيوانات ترانسژنيك

Transgenic animals and gene pharming

The term pharming comes from a combination of the words farming and pharmaceuticals; a blending of the basic methods of agriculture with advanced biotechnology. Gene pharming is a technology that scientists use to alter an animalʹs own DNA, or to splice in new DNA, called a transgene, from another species. In pharming, these genetically modified (transgenic) animals are mostly used to make human proteins that have medicinal value. The protein encoded by the transgene is secreted into the animalʹs milk, eggs or blood, and then collected and purified. Livestock such as cattle, sheep, goats, chickens, rabbits and pigs have already been modified in this way to produce several useful proteins and drugs. A transgenic animal is one that carries a foreign gene that has been deliberately inserted into its genome. The foreign gene is constructed using recombinant DNA methodology. Two methods of producing transgenic animals are widely used: (1) transforming embryonic stem cells (ES cells) growing in tissue culture with the desired DNA and (2) injecting the desired gene into the pronucleus of a fertilized egg. Desirable genes from one species are transferred to other animals or species to improve the productivity of livestock. Faster growth rates, leaner growth patterns, more resistance to disease, increased milk production, more efficient metabolism, and transferring antimicrobial genes to farm animals are some of the goals of transgenic animal researchers.