A “perfume” to prevent disease

Early in 1999 John R. Carlson, Ph.D., the Eugene Higgins Professor of Molecular, Cellular and Developmental Biology, reported that his laboratory had identified 16 odor receptor genes in fruit flies (See “Researchers Discover Odor Receptor Genes in Fruit Flies,” Spring 1999). It was the first finding of such genes in insects. Carlson and his colleagues went on to find taste receptor genes in fruit flies and to identify the functions of specific odor receptors in mosquito antennae.

Now Carlson’s laboratory is part of an international team that plans to harness those findings to reduce the spread of malaria, which kills 1 million people each year, mostly in the developing world. The female mosquitoes that spread the disease are drawn to certain human odors, which they “smell” with receptors in their antennae. The team, which includes scientists in the United States, the Netherlands, Tanzania and Gambia, hopes to create a “perfume” that will either lure malaria-carrying mosquitoes into traps or act as a repellent.

Scientists at Yale and Vanderbilt University will identify odors that affect mosquitoes and will create the “perfumes.” Dutch researchers will study the effects of the odors on mosquito behavior in the laboratory. And the African scientists will field-test the odors. The $8.5 million, five-year project is funded by the Bill & Melinda Gates Foundation’s Grand Challenges in Global Health initiative. Ultimately, the scientists hope the odors they develop will prevent malarial mosquitoes from infecting humans, and will be inexpensive, safe and easy to use in rural areas. This approach could also be applied to mosquitoes that carry dengue fever or the West Nile virus. “With insect-borne diseases, the best way to control the disease is usually to control the insect,” Carlson said. “We smell good to the mosquitoes, so if we can understand in molecular detail how the insects are attracted to us, we might be able to devise new means of controlling them.”