It’s a terrifying thought that mosquitoes, no bigger in wingspan than your pinkie nail, are responsible for nearly a million deaths every year since they infect humans with such deadly diseases as malaria, dengue fever, Zika and West Nile. That’s why researchers have been hard at work to develop means of curbing mosquito populations — and may have discovered a breakthrough.
Scientists at the University of Arizona recently discovered a protein in mosquitoes necessary for reproduction. With this information, they hope to develop “birth control” for the annoying insect.
The protein, which they call eggshell Organizing Factor 1, or EOF-1, is found in female mosquitoes and responsible for producing viable eggs, according to findings published last week in the open access journal PLoS Biology.
Researchers were able to block the protein, leading to defective egg shells and embryo death of newly conceived mosquitoes. This protein, they say, exists only in mosquitoes — therefore any drug developed to hinder it could not affect the reproductive processes of other animals, including humans.
“We specifically looked for genes that were unique to mosquitoes and then tested for their functional role in eggshell synthesis,” lead researcher Jun Isoe tells UANews. “We think there are other discoveries to be made using this same species-directed approach.”
The genes involved in mosquito reproduction had not yet been identified until this research. Once Isoe’s team found the genes to target, they used an approach called RNA interference, or RNAi, to suppress the molecules that direct these genes to produce certain reproductive proteins.
Blood meals are required for female mosquitoes to produce eggs, which take about three days more to lay, regardless of their blood intake. Scientists found that the mosquitoes that were injected with the RNAi molecules produced abnormal eggs for the duration of their two- to three-week life span.
Researchers hope to develop drugs to interfere with the EOF-1 protein in high-risk areas where mosquito-borne human diseases are most threatening.
“The inhibitors currently available to control mosquitoes have been used for so long that the pests are becoming resistant to them,” says Roger Miesfeld, professor and head of the Department of Chemistry and Biochemistry at UA. “Our idea is to knock their populations down to a level where you can break the cycle of disease transmission between mosquitoes and humans.”