Researchers from Imperial College London may have come up with a novel way to reduce the risk of malaria—interrupting the fertilization process among mosquitoes who carry the disease. The Anopheles gambiae species of mosquito, which is largely responsible for the transmission of malaria throughout Africa, mates only once in a lifetime, meaning that if scientists can foul up fertilization just once, it may help dramatically reduce numbers of the insects, and therefore, their ability to spread disease.
The study, published in the open-access journal PLoS Biology, focuses on the “mating plug,” a mixture of post-ejaculatory proteins that harden to effectively seal in the semen after sex, and increase the odds of insemination. (Sound gross? It’s actually a common feature of many creatures’ sex lives. The researchers explain that “components” of mating plugs are evident in species from primates—including humans—to rodents and bugs. As for what these plugs are made of, that varies. The authors write: “Mating plugs often comprise proteins, lipids or mucins, but in invertebrates they can even be formed from part of the male’s genitalia, which may result to permanent damage to the male, or even death.” Ouch.)
Researchers found in lab tests that by targeting a specific protein produced by male mosquitoes, they were able to reduce the insects’ ability to produce mating plugs, and therefore reduce the likelihood of reproduction. When the bugs who had been genetically tweaked, so to speak, mated with females, their odds of insemination were significantly reduced. As the authors write, “The vast majority of females mated to these males did not receive a plug and were not inseminated.”
These promising findings may introduce a new way to prevent the spread of malaria, researchers say, and could have widespread benefits if the effects can be replicated outside of a lab setting. As Dr. Flaminia Catteruccia, lead researcher on the study, told the BBC:
“If in the future we can develop an inhibitor that prevents the coagulating enzyme doing its job inside male A. gambiae mosquitoes in such a way that can be deployed easily in the field – for example in the form of a spray as it is done with insecticides – then we could effectively induce sterility in female mosquitoes in the wild… This could provide a new way of limiting the population of this species of mosquito, and could be one more weapon in the arsenal against malaria.”
As many as 500 million people suffer from malaria each year, and roughly one million die annually from the disease—most of whom are young children in Sub-Saharan Africa, according to the Centers for Disease Control.