Closing the gap to effective gene drive in Aedes aegypti by exploiting germline regulatory elements

CRISPR/Cas9-based homing gene drives have emerged as a potential new approach to mosquito control. While attempts have been made to develop such systems in Aedes aegypti, none have been able to match the high drive efficiency observed in Anopheles species. Here we generate Ae. aegypti transgenic lines expressing Cas9 using germline-specific regulatory elements and assess their ability to bias inheritance of an sgRNA-expressing element (kmo(sgRNAs)). Four shu-Cas9 and one sds3-Cas9 isolines can significantly bias the inheritance of kmo(sgRNAs), with sds3G1-Cas9 causing the highest average inheritance of similar to 86% and similar to 94% from males and females carrying both elements outcrossed to wild-type, respectively. Our mathematical model demonstrates that sds3G1-Cas9 could enable the spread of the kmo(sgRNAs) element to either reach a higher (by similar to 15 percentage point) maximum carrier frequency or to achieve similar maximum carrier frequency faster (by 12 generations) when compared to two other established split drive systems.

Automated summary

CRISPR/Cas9-based homing gene drives are a potential new approach to mosquito control. In this study, researchers successfully generated transgenic Ae. aegypti lines expressing Cas9, which significantly biased the inheritance of an sgRNA-expressing element. The sds3G1-Cas9 isolate showed the highest average inheritance, indicating its potential for driving the spread of the targeted element more efficiently.