Researchers to try to map genome of zebra mussel

Call it the Zebe Genome Project.

University of Minnesota scientists Tuesday announced they will try to be the first in the world to map the entire genetic sequence of Dreissena polymorpha, aka the zebra mussel, the invasive mollusk spreading across waters in Minnesota and the country.

But unlike the Human Genome Project, which aspires to benefit humanity, the U's project could spell bad news for zebra mussel-kind.

"Like all species, zebra mussels have weaknesses that can be exploited for control, and we want to find those," Michael McCartney, the project's lead researcher and a professor at the University's Minnesota Aquatic Invasive Species Research Center, said in Tuesday's announcement. The center is teaming up with the U's Genomics Center on the effort.

The project's immediate goals aren't quite as ambitious as genetic warfare, however.

By the end of the year, the team hopes to have mapped the entire sequence of one single zebra mussel from Minnesota, a roughly $25,000 endeavor. According to the U, only one other bi-valve mollusk, an oyster, has ever been fully sequenced.

Scientists will compare that "draft" sequence from the one "zebe," as they have become casually known, with hundreds of other samples of zebra mussels from around the world, providing a complete and "finished" DNA sequence of the organism.

Subtle genetic differences, scientists hope, will provide clues as to how zebra mussels are spreading.

For example, the team might be able to trace whether the invasive mussels in Lake Mille Lacs came from the Mississippi River or the Great Lakes. Researchers hope that information will allow regulators to more efficiently target prevention efforts. That portion of the project could take another year, according to Becca Nash, associate director of the Invasive Species Research Center.

The genetic sequence will be made available to the public, and McCartney said, that's when other researchers, such as those with expertise in mollusk immune systems, can begin to scheme up ways to exploit the unwelcomed life form. Natives of Russia, zebra mussels have been spreading across the state, often hitching rides on boats, trailers and docks and then establishing themselves in new waters.

Although the ultimate ecological impact isn't known, biologists have witnessed fundamental changes in a lake's chemistry once an infestation occurs.

From a recreational standpoint, the zebes' sharp shells have made barefoot beach-walking a painful affair in some areas, and boats often complain of the regulatory burdens, such as draining all water from a boat, that lawmakers and wildlife officials have enacted in an effort to slow the spread of zebra mussels and a host of other non-native invasive species.

"Right now, we're focused on step one," he said.

"Ultimately, though, we have our sights set much higher."