Genetically Modified Mosquitoes Lose Interest for Human Blood
With summer around the corner, mosquitoes will start to come out. Although these pesky insects are relatively small, they sure pack a punch in a single bite. Not only do mosquitoes leave behind a small itchy and red bump, some mosquitoes depending on the region of the world, carry deadly infections, such as the malaria parasite. Since these insects can be a huge threat, researchers have looked into ways of protecting people from mosquito-borne infections. In a new study, instead of creating a vaccine or a product to ward off mosquito bites, researchers decided to genetically modify the actual mosquito. They created mutated mosquitoes that could no longer smell out humans as opposed to other animals.
Although some mosquitoes will choose to bite animals, two types of mosquitoes, the Aedes aegypti and the Anopheles gambiae, are known to seek out humans. According to the study leader, Leslie Vosshall, a neurobiologist from the Rockefeller University in New York, "[these mosquitoes] love every about us. They love out beautiful body odor, they love the carbon dioxide we exhale and they love our body heat."
In this study, Vosshall and colleagues took A. aegypti mosquitoes and genetically modified them by removing the gene, orco. Orco is responsible for making a protein that contributes to the creation of receptor molecules, which give the insects their sense of smell. The team found that mosquitoes without this gene had a more difficult time smelling humans out from other animals. However, the researchers also found that even though the mosquitoes could not distinguish between a human arm and a guinea pig, they were not hesitant about feeding on either subject.
Since the genetic mutation removed the mosquitoes' sense of smell, they were also no longer deterred by the popular insect repellent, DEET (N,N-diethyl-meta-toluamide). However, researchers found that once these mosquitoes landed on a body part sprayed with DEET, they fled, which suggests that DEET would still protect people from these mutated mosquitoes.
"It's unbelievable to me that people have been spraying DEET on skin for upwards of 60 years. We don't have any clear idea of how or why it works, and that as a scientist just drives me crazy," Vosshall said according to Nature.
The research team plans on studying how other sensations could potentially repel mosquitoes. The study was published in Nature.