Lab chat: How a set of receptors on mosquito antennae help them find humans

A new study shows that different genes are likely working together to help mosquitoes track down humans using their antennae. Using CRISPR-Cas9, scientists modified three sets of mosquitoes: one had a defunct olfactory gene Ir8a; one was missing a functional olfactory gene known as orco; and a third had both genes disabled. These mosquitoes were then released into a chamber to see if they were attracted to different humans. I spoke to study author Dr. Matthew DeGennaro of Florida International University about the research, published in Current Biology.

What did you find? 

We found that the [Ir8a mutant] mosquitoes lose behavioral sensitivity to lactic acid and other acidic compounds in sweat. These Ir8a mutants had a 50 attraction rate to the human. But different people are also more or less attractive to mosquitoes because there are some things going on in people, too. I was really shocked that the Ir8a mutants had such a strong effect on attraction because the orco mutants, when carbon dioxide was present, had basically no effect on mosquito attraction. And then the double mutant had an additive effect that is a little bit lower [than the 50 percent].

How could we use this to fight off mosquitoes? 

So, basically the idea is to generate a lifesaving perfume that would make us invisible to mosquitoes. If we understand how mosquitoes perceive humans, that's the key to dealing with the problem.