MOUSE: WIKIMEDIA COMMONS, RAMA, DNA: ISTOCKPHOTO.COM
Research involving the integration of human DNA, cells, or tissues into animals has been undertaken since the 1960s. Transgenic animals (with one or more human genes in their makeup) and chimeras (with some human cells or tissues amongst their own animal tissues) are now important biomedical research approaches. They are used in studies where it is morally or practically impossible to conduct the experiments in humans, and where alternative approaches, such as computer simulations or cell cultures, are not adequately representative of the system being studied. Such approaches are used to determine the function of human genes by expressing the relevant DNA segment in an animal and observing its effect, or to test, develop, and produce therapies for disease, among other applications.
Chimeric mice, for ...