Are summertime mosquitoes making you slaphappy? Growing up in Minnesota, where we often used to joke that the mosquito was the unofficial State bird, mosquitoes were always the bane of summertime existence. But now, new research suggests there may be a way to curb the mosquito population . . . which is not only a human nuisance, but is also responsible for diseases like malaria, yellow fever, and dengue fever.
A team of biochemists at the University of Arizona has discovered that when they block a cellular process in mosquitoes they will die soon after a blood meal. This process is called
vesicle transport and mosquitoes depend on it for digestion. According to Roger Miesfeld, a professor in the UA’s department of chemistry and biochemistry, “The idea behind our research is this: if we can kill the mosquito after she bites the first person, she won't be able to bite and infect a second. We do this by blocking the mosquito's ability to digest its blood meal.”
Only female mosquitoes feed on warm-blooded mammals.
Tinkering with mosquito’s guts.Interestingly enough, a mosquito can ingest its body weight in blood (gross!). This poses a huge metabolic challenge. And if the female mosquito can’t complete the digestive process, then numerous biochemical processes are disrupted. As a result, the mosquito can't carry through with egg production. Though mosquitoes can receive nutrients from flower nectar to maintain their body functions, large amounts of protein are needed when it is time to produce eggs. If they can find enough victims to bite and avoid being slapped, they can live for several weeks and lay hundreds of eggs.
The research team used a technique called RNAi to target genes involved in the mosquito's digestion process. They focused on a protein complex called COPI which is necessary for mosquito cells to secrete digestive enzymes into the guts. By eliminating this secretion process, the mosquitoes tested in the study were not able to digest the blood meal. What’s more, over 90% of them died within two days after feeding on blood.
The COPI RNAi doesn't have any negative effect on female mosquitoes for 10 days unless they feed on blood. Then the whole lining of the gut starts to disintegrate and blood seeps into the mosquito's body.
Developing a harmless mosquito insecticide.The ultimate goal of this research is to develop a mosquito-select insecticide that would not have any effect on humans. Though it's highly unlikely that mosquito-transmitted diseases such as dengue fever and malaria will be completely eliminated, this new research does give scientists another strategy to use in combatting mosquito-borne illnesses.
