Discoveries
Technique yields clear picture of worm's genetic makeup
The next time you hear someone confidently assert that there are about 30,000 genes in the human body, it's wise to be a bit skeptical. The current map of the human genome was made using computer projections of genes' likely locations within individual chromosomes, but the accuracy of those predictions is not perfect.
In a recent study, Dana-Farber researchers presented a way of pinning down genes' locations and makeup more precisely. Investigators led by Marc Vidal, PhD, used a powerful gene-mapping technique to produce the clearest picture yet of the genetic makeup of one animal, the microscopic worm Caenorhabditis elegans (known as C. elegans). Their success demonstrates that the same approach may be used to better understand the genes in human cells and produce pure samples of cell proteins — critical to understanding both how cancer cells function and how they can be fought.
An image of C. elegans, a microscopic worm used widely in genetic studies around the world.
To locate the genes in C. elegans, Vidal and his colleagues devised a technique that focuses on blocks of genetic material called open reading frames, or ORFs, which serve as templates for producing proteins. The investigators located the full set of ORFs in C. elegans cells and compared them with computer projections of where the worm's 19,000 genes lie. They found that in more than half the cases (56 percent), the predicted genes did not completely match the actual genes isolated in their study.
"This demonstrates that even in C. elegans, whose genome is better understood than that of humans, the genome map needs a great deal of correcting and refining," says Vidal. "It also offers a practical way to generate and then characterize the function of most of the proteins made by cells, which is becoming an increasingly important area of cancer research."