Controversial ‘gene-drive’ strategy could make mosquitoes hostile to malaria parasites
Controversial ‘gene-drive’ strategy could make mosquitoes hostile to malaria parasites
Tags: Anopheles, Gene drive, Malaria, MosquitoesMitch Leslie, Science, 2025.
To fight malaria and the mosquitoes that spread it, people have drained swamps, showered their homes with insecticides, slathered themselves in noxious repellents, hidden under netting at night, and invented the gin and tonic—as a palatable way to take the bitter antimalarial quinine. Now, researchers report in Nature that they have borrowed a weapon from the mosquitoes themselves. The team genetically engineered mosquitoes to be resistant to parasites that cause malaria by inserting a version of a gene naturally found in some of the insects. They also enlisted a genetic trick known as gene drive to speed the gene variant’s spread through mosquito populations in the lab. The strategy is not ready for field testing, researchers caution. But the experiments “are elegantly designed and sound, really showing great proof of principle for driving natural variants of mosquito genes into a population,” says functional geneticist Tony Nolan of the Liverpool School of Tropical Medicine, who wasn’t connected to the study.
Despite improvements in prevention and treatment, malaria, caused by parasites of the genus Plasmodium, still kills about 600,000 people every year. For more than a decade, researchers have been trying to genetically alter mosquitoes to either reduce their populations or make them less hospitable to malaria parasites. For example, one group has engineered mosquitoes to produce antibodies derived from mice that stymie the parasites’ development. Such approaches come with technical problems. For one thing, researchers must ensure their genetic tinkering doesn’t lead to weakened mosquito strains that would die out quickly when released into the wild. They also have to find a way to make the genes that convey resistance spread quickly through entire mosquito populations. To solve that problem, scientists have turned to an approach known as gene drive that breaks the rules of inheritance. A mosquito would typically transmit a genetic change to 50% of its offspring. Gene-drive technology, which often relies on a genome editor, boosts the odds that the modification will be passed down to the next generation, allowing its frequency to increase rapidly in a population. The approach is controversial, however, in part because it has the potential to make irreversible changes to a species with unpredictable effects on ecosystems. So far, researchers have not tested it in the wild.
