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.

Although only a small percentage of requests for leave are granted by the Supreme Court of Canada, legal observers say that the court is likely to take this case up--especially because Chief Justice Beverley McLachlin has suggested that the court would like to consider biotechnology issues.

"It's almost certain," said Margaret Somerville, a law professor at McGill University who follows the Canadian courts.

Important in Canada

Although the Canadian patent means little financially for Harvard or DuPont, it has become a landmark case in Canadian patent law.

At issue is the heart of the patent code: the definition of the word "invention" itself.

The Court of Appeals ruling took a sweeping view of inventions that describes both animate and inanimate objects as "compositions of matter" that can be patented.

Justice Marshall Rothstein wrote that "nothing in the term 'composition of matter' suggests that living things are excluded from the definition" of invention.

The Canadian Justice Department disagrees with this interpretation.

"We think the court...erred in determining that these non-human mammals could be considered a 'composition of matter' within the terms of the Patent Act," said Rick Woyiwada, the government laywer on the case. "Similarly, we think they erred in determining that the non-human mammals can be considered an invention."

Legal experts say that the decision will depend largely on whether the court focuses on the meaning of the patent code or whether it takes a more philosophical perspective in its analysis.

"If they use a legalistic framework, they'll uphold the Court of Appeals," Somerville said. "But it's almost certain that the court will do a broader-based social and symbolic analysis as well as a technical legal analysis."

However, it is hard to predict what the Supreme Court will decide if it chooses to review the case because it has considered so few biotechnology matters.

"The court hasn't dealt much with biotechnology, and the highest case that got there on patenting life forms had to do with selective breeding, not genetic biotech intervention," said Michelle Swenarchuk, director of international programs at the Canadian Environmental Law Association, which lobbied the government to appeal.

In general, the court is known for its conservatism.

"In almost any field of law they are not inclined to break out and start smashing paradigms," said David Beatty, a University of Toronto law professor. "It's cautious in most areas of its work. If this case is going to ask it to do anything beyond the norm, [the court] will be a chameleon."