Abstract

A number of techniques for directly manipulating the mammalian germline have been established in the mouse. During the past five years these have been applied to domestic livestock but, so far, only pronuclear microinjection has proved successful. The considerable resources required and the low efficiency of the procedure are major limitations and, worldwide, relatively few laboratories have produced transgenic livestock. In applying rtransgenic technology to farm animals, a major effort has gone into the manipulation of growth. This is a complex trait and progress has been constrained by the inability to control the expression of transgenes in a precise manner, and by the lack of basic knowledge at the interface between molecular biology and physiology. By contrast, the production of biomedical proteins from transgenic animals involves the manipulation of a relatively simple trait, milk composition. So far, only relatively low levels of protein production have been reported for transgenic sheep. However, very high levels of expression of human a1-antitrypsin have been obtained in transgenic mice, demonstrating the feasibility for this application of transgenic animals.

KL, Macmillan, and GW Asher

Proceedings of the New Zealand Society of Animal Production, Volume 50, , 123-134, 1990