Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news about fascinating discoveries, scientific advances and more.
CNN
—
If you always thought you might be just a mosquito coil, scientists are now showing proof. A new study suggests that mosquitoes are more attracted to certain humans than to others.
A research team led by Leslie Vosshall, a professor at the Rockefeller University and director of the Laboratory of Neurogenetics and Behavior, has identified why certain people seem to attract more mosquitoes than others. I tried. Published in Cell magazine October 18th.
Over three years, researchers asked a group of 64 volunteers to wear nylon stockings on their arms for several days for six hours a day. Maria Elena Deobardia, the first author of the study and a former postdoctoral fellow at Rockefeller University, said the researchers called the “two-choice olfactometer,” an acrylic glass her chamber into which the researchers put her two stockings. ” was built. The research team then released yellow fever mosquitoes, scientifically called Aedes aegypti, into the chamber and observed which stockings attracted more insects.
The test allowed researchers to divide study participants into “mosquito magnets,” whose stockings attracted many mosquitoes, and “low attractants,” whose stockings did not appear to attract insects. Scientists scrutinized the skin of mosquito magnets and found 50 more molecular compounds in these participants than in others.
Bosshall, who is also chief scientific officer at the Howard Hughes Medical Institute, told CNN: But one difference stood out in particular. The reason is that the skin of the mosquito magnet contains a lot of carboxylic acid.
Carboxylic acid is contained in sebum and forms a barrier with oily substances to keep the skin moisturized.
Carboxylic acids are large molecules, explained Vosshall. They “do not smell so bad on their own,” she said.
One participant, identified only as subject 33, was the best beauty to mosquitoes. The subject’s stockings attracted 100 times more mosquitoes to her than the least attractive participant.
Also, levels of human attractiveness appeared to remain fairly constant over time for participants monitored over three years, Vosshall said.
For example, subject 33 “never took a day off from being the most attractive person”.
When it comes to Aedes aegypti, female mosquitoes prefer to use human blood to fuel egg production, lending urgency to the quest to find human prey. Smaller predators use a variety of mechanisms to identify and select humans to bite, Boschall said.
Carboxylic acids are just one piece of the puzzle that explains how pesky insects select targets. The heat and carbon dioxide we give off when we breathe also attract mosquitoes to humans.
Scientists still don’t know why carboxylic acids seem to attract mosquitoes so strongly, Vosshall said. I can’t.
“You can’t completely strip natural moisturizers from your skin. That’s bad for skin health,” she said. He said it might help reduce mosquito bites.
“Every time these mosquito bites put people at a public health risk,” she said. “Aedes aegypti is a vector for dengue, yellow fever and Zika. People who are like magnets are much more likely to catch the virus.”
Matthew DeGenaro, an associate professor of neurogenetics in mosquitoes at Florida International University, told CNN that the findings suggest specific factors that make mosquitoes love certain people more than others. He was not involved in the research.
“This study clearly shows that these acids are important,” he said. “It’s interesting how mosquitoes recognize these carboxylic acids because these Certain chemicals are so heavy that it is difficult to smell them from a distance.
“It’s possible that these chemicals are being altered by, say, the skin microbiome, and that could be causing some sort of malodorous plume. Alternatively, other factors in the environment could be changing these. It breaks down chemicals a little bit, which may make it easier for mosquitoes to detect.”
The results “are also a very good example of how insects can smell,” added DeGennaro. “This insect evolved to hunt us.”
For DeGennaro, the persistence of certain human attractions is one of the most interesting aspects of his research.
“I didn’t know there was such a stable mosquito preference for certain people,” he said. “It could suggest that the skin microbiome is important, but they haven’t addressed it.”
To understand why mosquitoes are attracted to certain compounds over others, more study of the microbiome that inhabits human skin is needed, he said. And that could lead to better products for reducing mosquito bites and the spread of disease.
“If we can understand why mosquitoes find hosts, I think we can design new repellents that block mosquitoes from sensing those chemicals,” said DeGennaro. “And this could potentially be used to improve current repellents.”
