It goes without saying that when your appetite is satiated, you're no longer interested in eating. Well, scientists have devised a method of artificially inducing that "full" feeling in mosquitoes, thus keeping them from going after humans for blood meals.
When female mosquitoes have fed, their bodies produce protein-like molecules known as neuropeptides. These in turn activate neuroreceptors in the insects' cells, causing the mosquitoes to hold off on additional feeding until they require more blood.
Led by postdoctoral fellow Laura Duvall, a team at New York's Rockefeller University set out to see if they could preemptively activate those receptors by administering neuropeptides to mosquitoes, stopping the initial feeding from occurring in the first place. The problem was, there were many different types of neuropeptides and receptors that would presumably have to be tried in multiple combinations.
Instead, the scientists simply looked to appetite-suppressing drugs for humans, which work by activating Neuropeptide Y (NPY) receptors. When female Aedes aegypti mosquitoes were fed a saline solution containing these drugs, a type of NPY-like receptor called NPYLR7 was activated within the insects. As a result, they showed no interest in a piece of nylon stocking that had previously absorbed Duvall's body odor. By contrast, when the mosquitoes were given a drug that inhibited their NPYLR7 receptors, the insects hungrily went after the stocking.
Introducing the existing drug-doped solution to mosquito habitats wouldn't be a good idea, however – once released into the environment, it could also affect humans or other non-target species. With that in mind, the researchers identified a molecule known as compound 18, which activates only the mosquito-specific NPYLR7. After ingesting that compound and being placed in a chamber with a live mouse, mosquitos ignored the rodent.
It is now hoped that a more potent version of compound 18 could eventually be placed in feeding stations, or even introduced through the semen of male mosquitoes that have been genetically modified to produce the substance themselves.
A paper on the research, which was conducted in the lab of Prof. Leslie B. Vosshall, was recently published in the journal Cell.
Source: The Rockefeller University
