Production of bioproducts through the use of transgenic animal models.

Transgenic livestock that produce recombinant proteins in their milk can provide an economic and safe system for production of valuable proteins, such as pharmaceutical proteins for treatment or prevention of human disease or biomaterials for medical use. This method of production is frequently referred to as biopharming. The promise of biopharming, that is the actual commercial production of pharmaceuticals and other bioproducts, is nearing fulfillment. Improvements in molecular and reproductive techniques and strong economic incentives have continued to drive the implementation of transgenic technology to domestic animals. Nuclear transfer using transgenic donor cells is rapidly becoming the predominant technique used in the production of transgenic livestock, replacing the direct injection of DNA into the zygotic pronuclei. Production of transgenic founder animals by nuclear transfer in combination with traditional reproductive technologies can result in the propagation of transgenic herds of sufficient size to meet market demands for commercially important proteins. While some of the companies that have established transgenic programs have run into setbacks owing to a combination of economic, scientific and regulatory difficulties, other companies are continuing to make significant advances. While further improvements are needed to increase efficiencies of production, economically viable production of recombinant proteins using livestock species is not only possible but should be a commercial reality in the very near future.