Researchers at the Mayo Clinic have designed a new tool for identifying protein function from genetic code after successfully switching individual genes off and on in zebrafish, and then observing embryonic and juvenile development, the clinic announced Monday.

The research has the potential to provide insight into how cancerous cells spread, what makes some people more prone to heart attacks and how genes play a role in addiction. Other more complex issues, such as the genetics of behavior, plasticity and cellular memory, stress, learning and epigenetics, could also be studied with this method.

The study examines protein expression and function from 350 loci among the zebrafish’s approximately 25,000 protein-encoding genes. Researchers plan to identify another 2,000 loci.

“I consider this particular system a toolbox for answering fundamental scientific questions,” said Dr. Stephen Ekker, a Mayo Clinic molecular biologist and lead author of the study that appears in the journal Nature Methods. “This opens up the door to a segment of biology that has been impossible or impractical with existing genomics research methods.”

About 50,000 fish are maintained in the Zebrafish Core Facility at the clinic in Rochester, Minn.