Anti-CRISPR Anopheles mosquitoes inhibit gene drive spread under challenging behavioural conditions in large cages

Abstract CRISPR-based gene drives have the potential to spread within a population and are considered as promising vector control tools. A doublesex-targeting gene drive was shown effective to suppress laboratory populations in both small and large cages, and it is considered for field application. Challenges related to the field-use of gene drives and the evolving regulatory framework demand for systems able to modulate or revert the action of gene drives, as part of post-release risk-mitigation plans. We developed an improved AcrIIA4-based anti-drive strain and showed inhibition of gene drive spread, in complex feeding and reproductive behavioural conditions. A stochastic model predicted the experimentally-observed genotypes dynamics in overlapping generations in medium- and large-sized cages and further demonstrated the effectiveness of anti-drive in different release and fitness scenarios. This study provides a further validation for the use of anti-drive system in controlling the spread of gene drive in Anopheles under complex behavioural conditions.