Mosquito Olfaction

Mosquitoes track down their next meal by using their sense of smell to lead them to a human or other host. Molecular understanding of olfaction in the mosquito Anopheles gambiae, the main vector of malaria in sub-Saharan Africa, could lead to better ways to control these pests and the deadly disease they transmit. A research team led by Yale University’s John R. Carlson has characterized the response of 50 mosquito odorant receptors to a diverse panel of 110 odorant molecules, including components of “human volatiles” (Nature, DOI: 10.1038/nature08834). Some narrowly tuned receptors respond to only a few odorants, and some biologically important odorants activate only a few receptors, the researchers found. For example, one receptor responds strongly to a small group of aromatics that includes indole, which is a component of human sweat. Other narrowly tuned mosquito receptors respond to 2,3-butanedione and 1-octen-3-ol, which are by-products of skin microbes, and 2-ethylphenol from urine. Carlson and coworkers also compared mosquito and fruit fly coverage of “odor space” and found that mosquitoes have greater coverage of aromatics than fruit flies, which focus on esters that are flavor and aroma components of fruits.