History of genetic engineering of laboratory and farm animals.

Abstract

In the last few hundred years, man has learned that the tools of ge netic selection are a powerful means of improving the utility of livestock. Genetic engineering of animals appears to be a logical extension of the man-animal relationship; albeit one that places more responsibility on man in his efforts to develop an ecosystem in which both man and animals persist. The prospects for genetic engineering of farm animals have improved dramatically because of recent discoveries in the field of gene regulation. Two fundamental tools have made possible the recently reported successful insertion of a cloned human growth hormone gene into pigs and sheep (21). These tools or biotechnologies are embryo micromanipulation and recombinant DNA technology. Judicious application of embryo manipulation and recombinant DNA will provide an opportunity to increase the utilization of animals for food, fiber, and biomedical products. Combining genetic manipulation with the well-established biotechnologies of semen and embryo preservation has increased man’s options for preserving genetic resources that at present seem to be dwindling through the loss of animal species in a technology-dominated world. In this chapter, I will discuss methods of genetic manipulation developed since 1950 that appear to have made the most impact on efforts to genetically engineer farm animals. I will also discuss the potential and problems that have arisen with different approaches to engineering animals. The development of recombinant DNA techniques is outside the scope of this chapter, but is obviously an essential part of genetic engineering.