Scientists pursued the plant gene for PC synthase for a number of years because of plants' tantalizing potential as easily harvested agents for cleaning contaminated sites. Rea and Cobbett's labs reported simultaneously in 1999 that they had isolated the plant gene for PC synthase.
But the Penn group didn't stop there. Working with sequenced genomes from a number of other species, including C. elegans, they set out to see whether the sequence existed outside the plant kingdom.
"This paper is another example of how having sequence data for entire genomes is helping to identify new genes," said Jonathan H. Freedman of Duke University's Nicholas School of the Environment. "It is likely that without the information obtained from the C. elegans genome project, researchers may never have looked for PC synthase in an animal."
For Vatamaniuk, who together with Bucher conducted most of the experimental work, the discovery of the C. elegans gene ce-pcs-1, coding for PC synthase, came as a major surprise. They followed that finding by determining that the worm gene was functionally equivalent to the gene in plants. Unlike wild-type worms, worms whose PC synthase gene was knocked out showed markedly greater sensitivity to heavy metals: they underwent extensive tissue damage, loss of fertility and eventually died.
Rea said that while biologists hold out great hope for plants to be used in cleaning sites contaminated with heavy metals, it's unlikely animals that can synthesize PC synthase will fill a similar niche. "Whereas plants are easy to harvest, invertebrates such as C. elegans, which is barely visible to the naked eye, are not," he said.
C. elegans is the third organism in which a gene for PC synthase has been
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Contact: Steve Bradt
bradt@pobox.upenn.edu
215-573-6604
University of Pennsylvania
6-Sep-2001