DNA Probe to Detect Veligers Developed

From January, 1996 (Update #26)

A new technique to detect larval zebra mussels is close to being developed by a research team at Rensselaer Polytechnic Institute (RPI). Sandra Nierzwicki-Bauer, chairwoman of biology at RPI and director of RPI's Darrin Fresh Water Institute, and postdoctoral research associate Marc Frischer are investigating the use of DNA genetic probes to test for the presence of zebra mussel veligers. The project was initiated in September 1994, with a $112,000 grant from New York Sea Grant. The most common technique for identifying zebra mussel veligers requires examining water samples under a stereo microscope equipped with cross-polarized light. By using the new DNA genetic probe, which still requires a microscope, the identification process will be much quicker and allow more water samples to be tested, Frischer believes. Using the new technique will not require the expertise of a highly trained scientist, he said. The researchers have already completed the first step of the project, which involved identifying a portion of the mussel's genetic makeup and a sequence of 1,800 segments. A probe is now being created that will link to only the RNA of the zebra mussel. The probe is a combination of a piece of DNA synthesized to match the sequence of the zebra mussel and a "reporter" molecule. Veligers will appear colored when the probe attaches to them. "This will allow us to get very sensitive detections, higher than what can be done right now microscopically, and has the potential of being automated," Frischer said. "The genetic approach is also providing information about the zebra mussel's evolutionary history which improves our basic understanding of this animal. We see our next steps as using the probe to study more of the ecology, the larval ecology, what happens to the veligers - how they move, mortality factors - and things we don't really have the answers to," Frischer said. - Judith N. Hogan, New York Sea Grant.

ID: 199601-4.

The Zebra Mussel Update was a 4- to 8-page quarterly national newsletter published by the University of Wisconsin Sea Grant Institute from May 1990 through May 1997. The ZMU documented the spread of the zebra mussel -- an exotic nuisance mussel -- through North America's freshwater environments, especially the Great Lakes, and on efforts to control it.