Scientists in California are reporting they've successfully genetically engineered a strain of mosquitoes that cannot be infected by the malaria parasite and so, they cannot transmit it to humans.
Using a technique known as gene editing, they've inserted new DNA into the mosquitoes' genes that will prevent malarial transmission, they report.
They've performed the technique on Anopheles stephensi mosquitoes, a leading malaria vector in Asia.
Not only will the modified mosquitoes not transmit malaria, the pathogen-resistant trait will spread quickly in a population of the insects, with 99.5 percent of the following generations carrying the new genes, researchers say.
That opens up the possibility that the technique can go a long way toward eliminating the disease that struck almost 200 million people in 2013, killing nearly a half million, says study leader Anthony James at the University of California, Irvine.
"We know the gene works," he says. "The mosquitoes we created are not the final brand, but we know this technology allows us to efficiently create large populations."
There's reason to believe the gene-editing process would work with other mosquito species as well, the researchers say in their study appearing in the Proceedings of the National Academy of Sciences.
The Irvine researchers worked with colleagues at the University of California, San Diego, to develop a technique to insert an engineered anti-malarial mutation into both copies of a particular gene in the insects, making it more likely to be passed along to subsequent generations.
They used a genetic engineering technique known as Crospr, which allows scientists to cut or snip DNA at a particular location in the genome and insert desired new or mutated genes in that spot.
The modified genes inserted into the mosquitoes bind with the malaria parasites, keeping them from recognizing its insect host and moving about in the mosquito's body.
"You can think of it as [being] blinded," James says, and as a result, the parasite cannot move into the insect's salivary gland, where transmission takes place when a mosquito bites a human.
This represents a significant first step, he says.
Much work remains to be done, and James notes that regulatory approval would be required from governments in foreign countries where malaria is endemic before the modified mosquitoes could be released in the wild.
