Gene Expression Helps Refine Water Monitoring
It’s pretty common for regulators to use the tiny water flea Daphnia magna to monitor freshwater toxicity. The organism is highly sensitive to contaminants in its environment, so counting dead water fleas can give investigators a decent sense of water quality.
However, this not-so-subtle “kill ‘em and count ‘em” technique doesn’t explain exactly how a toxicant is affecting the organism. Now researchers from nutritional sciences and toxicology have found a better way: by looking at characteristic changes in the organism’s gene expression. Graduate student Helen Poynton and her mentor, associate professor Chris Vulpe, published their findings last winter in the journal Environmental Science & Technology.
“The extra information we get from looking at gene expression could help us make more informed decisions about how harmful a toxicant is,” says Poynton. “It could give regulators a new direction that we should be pursuing in monitoring water quality. For instance, we could find that it’s necessary to regulate toxicant levels at lower levels, so we can act before toxicants get to the level of actually killing a population.”
Toxicogenomics could also be used for chemical screening, the researchers say. “For those in industry, chemicals could be screened for potentially ecological consequences while they are still in development,” said Poynton. “In pursuing 10 different chemicals for one application, it may be discovered that one is particularly toxic, so it can be ditched right away. At the same time, if screening reveals that there is little or no impact on gene expression from a particular chemical, why not pursue that one for commercial development?”