Multiplexed guide RNAs improve homing gene drive efficiency against spotted-wing Drosophila

Drosophila suzukii, the spotted-wing drosophila, is a globally invasive pest species that damages soft-skinned fruit crops and is currently managed predominantly with broad-spectrum insecticides. Rising pesticide resistance and regulatory constraints have stimulated interest in CRISPR-based genetic control strategies as alternatives.

A preprint posted to bioRxiv describes the further development of a homing gene drive targeting the female-specific exon of doublesex, a conserved sex-determination gene. The authors' earlier system achieved highly efficient inheritance (94–99 per cent) in both male and female germlines. However, a major limitation of homing gene drives is the emergence of resistance alleles — variants at the target site that are not cleaved by the Cas9 nuclease and therefore escape drive propagation. In the new work, the team employed multiplexed single-guide RNAs (sgRNAs) targeting multiple sites within doublesex simultaneously, with the aim of reducing the probability that any single resistance allele escapes all guide RNAs.

The preprint has not yet been peer-reviewed. Gene drive research raises significant ecological and governance considerations; established frameworks from bodies including the WHO and the National Academies of Sciences, Engineering, and Medicine call for staged, geographically contained testing and broad stakeholder engagement before any environmental release.