Human STD found in sturgeon genome.

• Position: Parasites - Sexually transmitted disease

While trying to find a DNA-based test to determine the sex of lake sturgeon, researchers at Purdue University, West Lafayette, Ind., found that the sturgeon genome contains trematode genes that did not originally belong to it and may harbor a protozoan parasite that causes a sexually transmitted disease in humans.

Genetics professor Andrew DeWoody and postdoctoral associate Matthew C. Hale found the parasite and pathogen genes while analyzing DNA from the gonads of lake sturgeon, a species that is on the decline because of overfishing and pollution of its habitats. The only way to determine a lake sturgeon's sex is to examine its internal sexual organs. DeWoody says about 15 genes found in the lake sturgeon came from Schistosoma, a parasitic worm. Lateral gene transfer from one organism to another is rare, especially in multicellular animals, but could be part of some evolutionary process for the sturgeon.

"Organisms may accept some new genes from other species because the new genes can serve as raw material for evolution," explains DeWoody. "The genome may be more fluid than we usually think." Hale indicates that genes often work in combination, and new genes one day may become involved with other genes to help the lake sturgeon create new traits needed to adapt to changes in its environment. "It isn't necessarily a bad thing for the sturgeon. It probably doesn't have a cost. It's...