The Canadian government asked its Supreme Court on Monday to hear the case of a famous genetically engineered mouse developed at Harvard.

The request for review marks the beginning of the final stage in a 15-year legal battle that has pitted Harvard against Canada.

The University wants exclusive rights in Canada to market mice that are genetically engineered to develop cancer. Harvard got a U.S. patent for "oncomice"--the first patent for any animal--in 1988, but its Canadian patent application has faced strong government opposition.

Harvard has licensed worldwide rights to the mice, which were developed by Andrus Professor of Genetics Phillip Leder '56, to chemical giant DuPont, Inc.

The University has 30 days to file a response to the government's petition before the court will take up the matter. If review is granted, the case would probably be heard in about a year.

In the Canadian justice system, the basic test in determining whether to grant leave is the broad public importance of a case. Harvard has yet to decide how to respond to the government's call for review, according to A. David Morrow, Harvard's top attorney on the case.

But at this point it is clear that Harvard's response will argue that the Canadian Federal Court of Appeals was correct in ruling that animals can be patented.

"We will argue that they should let the court of appeals decision stand because the judgment is so clearly right," Morrow said.