Transgenic food animals

A Survey of publicly available information

(December 2003)

By Gregory S. Harper* , Alan Brownlee, Thomas E. Hall, Robert Seymour, Russell Lyons, Patrick Ledwith

CSIRO Livestock Industries, 306 Carmody Rd., St. Lucia, Qld 4067

Executive Summary

The last decade of animal research has reinforced the view that some food-related qualities of animal products (e.g. eating quality and yield) are strongly influenced by the genotype of the animal. Likewise animal production performance characteristics (e.g. growth rate and disease resistance) have been improved by selective breeding. One significant advantage of transgenesis is in rapid genetic improvement of traits of interest, and a dramatic example of its impact can be seen in transgenic coho salmon that grow up to 11 times faster than their non-transgenic conspecifics. Nonetheless there are legitimate science-based concerns about the impact of these new methods on the production systems and the environments in which they grow as well as the food supply chains.

In this review, we describe the field of animal transgenesis with special reference to food animals. We have collected information by thorough searches of the scientific literature, the popular press and Internet websites. This information was supplemented with personal interviews of thirty-seven practicing research scientists from a range of research and teaching organisations. We now describe transgenic modifications of five terrestrial production species, and several transgenic mouse lines that are informative for developments in these five species. We also describe transgenic developments in thirteen aquaculture species. In each case we have made extensive use of published information, and have cited these references for the reader. The use of transgenic animals for xenotransplantation or human bioactive protein production is considered only briefly. A real issue for consideration by the regulatory authorities is whether individual transgenic animals that express the transgene poorly, and hence are substantially equivalent to their non-transgenic relatives, can be safely introduced into the food chain.

The review covers the techniques currently being used to produce transgenic animals, the techniques that might be used to trace transgenes in animals and the products derived from them and finally we discuss some issues associated with stability of the introduced transgenes. Whenever reasonable, we present predictions about future developments in the field of food animal transgenesis.