Stanford's Botstein agrees. You're looking at the forest, not just the tree. Stocks of mutant nematode worms, such as the ones shown at left, help researchers quickly home in on gene function. It is much simpler to evaluate gene function in the worm than in, say, a human. RNAi involves simply injecting worm oocytes with a piece of double-stranded RNA that matches the gene and somehow blocks its expression.
Experimenters then look for changes in the worms that develop from the injected eggs.
There's even some hint that eventually researchers may be able to mix the RNA with a worm's meal and then study the effects of having the gene inactivated in the animal's offspring. Then, researchers can find out when and where in the worm the hybrid gene is expressed by monitoring GFP's glow. To further speed the study of C. elegans gene function, Coulson is working with Robert Barstead at the Oklahoma Medical Research Foundation in Oklahoma City and Don Moerman at the University of British Columbia in Vancouver on a large-scale effort to generate large numbers of mutant worms. They have chemically induced mutations in about a half-million worms and are now screening them for interesting defects. Using the mutants, RNAi technology, and GFP proteins, these scientists can begin to learn more about how the gene at fault functions.