A Unlikely Star of Science

Jonathan Freedman Looks to Microscopic Roundworms to Document the Effects of Toxic Chemicals

By Monte Basgall

  In its natural environment C. elegans spends its brief life dining on microbes in the soil. But Nicholas School researcher Jonathan Freedman and his funding agency envision that in a laboratory setting, these simple animals may substantially reduce—and in some cases eliminate—the need for expensive large-scale rodent studies to screen chemicals for several kinds of toxicity.

  The reason is that the tiny roundworm’s 959 cells contain a striking number of genes and proteins that function similarly to those of higher animals, including humans. That has made C. elegans such an important model organism for biomedical research that its entire genome has already been sequenced—not far behind the genomes of fruit flies and humans.

  Freedman, associate professor of environmental toxicology, has worked with the worms since graduate school. He is now gearing up to exploit that rapidly
accumulated knowledge with the aid of robotic sorting and computer analysis funded by the National Toxicology Program (NTP), which is headquartered in nearby Research Triangle Park, N.C.

  “The idea is to quickly screen chemicals with C. elegans so you don’t have to do so many mega-rat studies,” Freedman says.

  “If Company X thinks it has a chemical that may be a nerve toxin or cause cancer, we will put it through our system to help find out. What we’ve done is save that company millions of dollars because it no longer has to do as large and expensive study on rats or mice.”

  “It can cost a company $10 million and it may have to go through 100,000
rats over a year or two just to do a complete study on one chemical. With our worms, I envision we’ll be able to get the whole thing done in a couple of weeks to maybe a month.”

  Freedman has a $2.4 million three-year contract with the NTP to evaluate the
feasibility of such a “high-throughput”

  C. elegans toxicity testing system. During this evaluation his group plans to expose developing roundworms to 200 different chemicals selected by the National Institute of Environmental Health Sciences, also in Research Triangle Park. Roundworms will also be used to evaluate chemicals’ effects on their neural systems at various stages of life.

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