An academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health. CAAT Newsletter Vol. Ph.D. Superficially, transgenic animal testing might appear to increase animal use. However, closer examination of this issue indicates that in many circumstances, transgenic technology can actually lead to a reduction in the use of larger animals and primates, as well as a decrease in the numbers of animals required to attain specific scientific objectives.
Transgenic animals are animals that carry new genes.
These genes are usually inserted by microinjection of purified DNA into the pronucleus of the fertilized egg. When inserted in this way, the new genetic material becomes integrated into the chromosomal DNA of the host organism, and transmitted as a heritable trait to succeeding generations of progeny. The resulting transgenic animal will then produce growth hormone from its liver. This technology has extraordinary power for elucidating fundamental mechanisms of gene regulation, and for performing insightful and useful genetic engineering trials. In many respects, transgenic mice and rats underscore the immeasurable value of research involving the intact organism for obtaining subtle information in crucial areas, such as fundamentals of gene regulation, physiology and developmental genetics.