Gene drive mosquitoes engineered to fight malaria

Mutant mosquitoes engineered to resist the parasite that causes malaria could wipe out the disease in some regions – for good.

Humans contract malaria from mosquitoes that are infected by parasites from the genus Plasmodium. Previous work had shown that mosquitoes could be engineered to rebuff the parasite P. falciparum, but researchers lacked a way to ensure that the resistance genes would spread rapidly through a wild population.

In work published on 23 November in the PNAS, researchers used a controversial method called ‘gene drive’ to ensure that an engineered mosquito would pass on its new resistance genes to nearly all of its offspring – not just half, as would normally be the case.

The result: a gene that could spread through a wild population like wildfire. “This work suggests that we’re a hop, skip and jump away from actual gene-drive candidates for eventual release,” says Kevin Esvelt, an evolutionary engineer at Harvard University in Cambridge, Massachusetts, who studies gene drive in yeast and nematodes.

For Anthony James, a molecular biologist at the University of California, Irvine, and an author of the paper, such a release would spell the end of a 30-year quest to use mozzie genetics to squash malaria. James and his laboratory have painstakingly built up the molecular tools to reach this goal.

The resulting mosquitoes passed on the modified genes to more than 99% of their offspring. Although the researchers stopped short of confirming that all the insects were resistant to the parasite, they did show that the offspring expressed the genes.