Dr. Stanley Prusiner, Dr. Fred Cohen, and colleagues at the University of California - San Francisco developed the mice, which develop the disease far more quickly than cattle, as test subjects to identify infected cattle and tainted products. We've engineered them to have a bovine gene.
Ordinary mice are highly resistant to the disease.
When injected with cells from infected cattle, the mice develop mad cow disease within a few months, which scientists hope to cut to 40 days or less with further adjustments. Cattle can take three to five years to display symptoms, and CJD usually takes decades to surface in humans. One of the doctors involved in the project, Dr. Steven J. Armond, told CNN that the mice may help answer scientists' questions about the disease, such as what parts of the cattle become infected, and which animal parts are dangerous to humans. Pruisner, one of the members of the UCSF team, won the 1997 Nobel Prize for medicine for his work on prions, microscopic protein particles believed to be involved in mad cow disease. The new test is still too slow to allow testing of individual cuts of beef, however.