A workhorse of modern biology is sick, and scientists couldn’t be happier. Researchers at Washington University School of Medicine in St. Louis, the Jacques Monod Institute in France and Cambridge University have found that the nematode C. elegans, a millimeter-long worm used extensively for decades to study many aspects of biology, can be targeted by naturally occurring viral infections. The discovery means C. elegans is likely to help scientists study the way viruses and their hosts interact. The findings will be published next week in the online, open access journal PLoS Biology.
Marie-Anne Felix, a research director at the Centre National de la Recherche Scientifique (CNRS, France), who studies the evolution of nematodes at the Jacques Monod Institute, began the study by gathering C. elegans from rotting fruit in French orchards. Felix noted that some of her sample worms appeared to be sick. Treatment with antibiotics failed to cure them. She then repeated a classic biological experiment that led to the discovery of viruses. Sick worms were ground up and passed through a filter fine enough to remove any bacterial or parasitic infectious agents. A new batch of worms was exposed to the ground-up remains of the first batch. When the new batch got sick, a viral infection was likely to be present.
David Wang, associate professor of pathology and immunology and of molecular microbiology at Washington University School of Medicine in St. Louis, specializes in the identification of novel viruses. He found the worms had been suffering infections from two viruses related to nodaviruses, a class of viruses previously found to infect insects and fish. Nodaviruses are not currently known to infect humans. Tests showed one of the new viruses can infect the strain of C. elegans most commonly used in research.