Refining Transgenic Mice

Refining Transgenic Mice

Emerging technologies allow researchers to make tissue- and developmental stage-specific knockouts | By Leslie Pray

Image: Courtesy of Taconic Farms
MOUSE HOUSE: Scientists at Taconic's Molecular Analysis Laboratory genotype transgenic rat and mouse lines.

Mice have been freeloading on humans for millennia. Now, in laboratories around the world, scientists are returning the favor. Model systems such as the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans are actually easier to work with than mice, but mice are more closely related to humans, making them better models of human physiology. "For modeling genetic diseases like breast cancer, you definitely need mammals," says Kay-Uwe Wagner, a molecular biologist at the Eppley Institute for Research in Cancer and Allied Diseases, Omaha, Neb.

Early in the 20th century, geneticists used inbred mouse strains for much...