A population modification gene drive targeting bothSaglinandLipophorindisablesPlasmodiumtransmission inAnophelesmosquitoes

AbstractLipophorin is an essential, highly expressed lipid transporter protein that is secreted and circulates in insect hemolymph. We hijacked theAnopheles gambiae Lipophoringene to make it co-express a single-chain version of antibody 2A10, which binds sporozoites of the malaria parasite Plasmodiumfalciparum. The resulting transgenic mosquitoes show a markedly decreased ability to transmitPlasmodium bergheiexpressing theP. falciparumcircumsporozoite protein. To force the spread of this anti-malarial transgene in a mosquito population, we designed and tested several CRISPR/Cas9-based gene drives. One of these is installed in, and disrupts, the pro-parasitic geneSaglinand also cleaves wild typeLipophorin, causing the anti-malarial modifiedLipophorinversion to hitch-hike together with theSaglindrive. Although producing drive-resistant alleles, theSaglin-based gene drive reached high levels in caged mosquito populations and efficiently promoted the simultaneous spread of the antimalarialLipophorin::Sc2A10allele. This combination is expected to affect parasite transmission by two different mechanisms. This work contributes to the design of novel strategies to spread antimalarial transgenes in mosquitoes, and illustrates some expected and unexpected outcomes encountered when establishing a population modification gene drive.