For the first time, scientists have used the gene-editing tool Crispr-Cas9 to render humans effectively invisible in the eyes of Aedes aegypti mosquitoes, which use dark visual cues to hunt, according to a paper recently published in the journal Current Biology. By eliminating two of that mosquito’s light-sensing receptors, the researchers knocked out its ability to visually target hosts.
“The better we understand how they sense the human, the better we can control the mosquito in an eco-friendly manner,” said Yinpeng Zhan, a postdoctoral researcher at the University of California, Santa Barbara, and the lead author on the paper.
Anopheles mosquitoes, which spread malaria, hunt at night, whereas Aedes aegypti hunts under the sun, at dawn and dusk. The species depends on a fleet of senses to find blood. A mere whiff of carbon dioxide, a sign that someone or something has just exhaled nearby, sends the mosquito into a frenzied flight.
“They can also detect some of the organic cues from our skin,” such as heat, humidity and stench, said Craig Montell, a neurobiologist at the University of California, Santa Barbara, and an author on the study. But if there is no suitable host, the mosquito will fly straight to the closest-seeming target: a dark spot.