The findings show that the excretory cells of the worm Caenorhabditis elegans a widely studied nematode used in genetics research -- express a specific gene that seems to help the species tolerate a high-salt environment. The findings are reported in the current online edition of Nature Genetics.

Related Caenorhabditis species also have this gene lin-48 but these worms don't express it like C. elegans does. As a result, the other worms died when exposed to the same levels of salt.

Somewhere along the evolutionary pathway, C. elegans developed the ability to survive in salty environments, said Helen Chamberlin, a study co-author and an assistant professor of molecular genetics at Ohio State. Lin-48 expression gives C. elegans some key advantages over its relatives; for one, there's less competition for living space.

"But no one has collected C. elegans strictly from a salty environment to see if indeed these worms thrive there to the exclusion of other Caenorhabditis species," Chamberlin said. "Quite frankly, the ecology of these worms' isn't well studied."

Learning how C. elegans differs genetically from its relatives could give researchers insight into how organ systems in more complex animals evolved. One example could be the human kidney.

"Changes in gene function are at the heart of evolutionary complexity," Chamberlin said. "The expression of lin-48 in its excretory cells adds a layer of complexity to C. elegans."

Chamberlin conducted the study with Xiaodong Wang, a postdoctoral researcher in molecular genetics at Ohio State.

They compared how several species of Caenorhabditis worms regulated salt intake. C. elegans and its relativ
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Contact: Helen Chamberlin
Chamberlin.27@osu.edu
614-688-0043
Ohio State University
18-Feb-2004