MOSQUITOES may home in on a particular component of sweat, genetic studies have revealed. The finding could lead to new ways of killing or evading the pests, and thus help combat malaria.
When the mosquito genome was sequenced, John Carlson of Yale University was intrigued by the similarity between certain odour-related genes in mosquitoes and those in the fruit fly. His team put the gene AgOr1 from the malaria-carrying Anopheles mosquito into fruit-fly neurons, to find out what odour molecule is detected by the receptor protein encoded by the gene.
A battery of food odours failed to elicit a response. But a chemical called 4-methylphenol, which is a component of sweat that Carlson describes as smelling like a horse barn, did the trick (Nature, vol 427, p 212). 鈥淭he neuron started responding like crazy,鈥� he says.
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In mosquitoes, the gene is expressed only in females, the sex that bites. And it switches off after a satisfying blood meal, which strongly suggests that it plays a key role in helping mosquitoes find their victims.
Even if 4-methylphenol is not the only or main attractant for mosquitoes, Carlson says that it could help scientists discover ways of luring the creatures to their deaths in traps or jamming their detection systems.