A Gene Drive with a Disappearing Act Can Aid Pest Control

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A Gene Drive with a Disappearing Act Can Aid Pest Control

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Shelby Bradford, PhD,  The Scientist,  2025.

Insecticides help combat infectious diseases carried by mosquitoes and other insects, but overuse of these products has resulted in insecticide resistance. In certain insecticides, the active compounds bind to voltage-gated sodium ion channels of the nervous system. However, a common point mutation in this ion channel changes a normal leucine to a phenylalanine, making the insects resistant to these compounds.1 “It’s like a soft spot in the protein,” explained Ethan Bier, a geneticist at the University of California, San Diego.

Bier’s group previously exploited this mutation to develop a gene editing tool, called a gene drive, that reverted the mutated ion channel in a fruit fly model back to the wild type version.2 Gene drives eliminate or modify undesired genes in an animal with CRISPR, and proliferate through a population because the drive is designed to always copy itself back into the genome. “The biggest problem of a gene drive—that’s also its biggest strength—[is that] it can spread automatically through the whole population,” said Philipp Messer, a population geneticist at Cornell University who was not involved in the study. Once introduced into a population, existing gene drives cannot be eliminated and are hard to confine. “Can we really justify to genetically change the whole species?” Messer added.

Bier recognized this concern as well. To address this issue, he and his team developed a modified gene drive system that did not copy the Cas9 and guide RNA. In a study published in Nature Communications, the researchers showed that this modified drive, which they called an allele drive, reverted the majority of an insect population to the target genotype while gradually eliminating the gene editing elements.3 The system offers an opportunity to revert mutated genes in organisms back to wild type form, enabling researchers to study insecticide resistance without permanently inserting gene editing machinery.