A population modification gene drive targeting both Saglin and Lipophorin disables Plasmodium transmission in Anopheles mosquitoes

E. I. Green, E. Jaouen, D. Klug, R. P. Olmo, A. Gautier, S. A. Blandin and E. Marois,  bioRxiv,  2022.07.08.499187. 2022.

Lipophorin is an essential, highly expressed lipid transporter protein that is secreted and circulates in insect hemolymph. We hijacked the Anopheles gambiae Lipophorin gene to make it co-express a single-chain version of antibody 2A10, which binds sporozoites of the malaria parasite Plasmodium falciparum. The resulting transgenic mosquitoes show a markedly decreased ability to transmit Plasmodium berghei expressing the P. falciparum circumsporozoite 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 gene Saglin and also cleaves wild type Lipophorin, causing the anti-malarial modified Lipophorin version to hitch-hike together with the Saglin drive. Although producing drive-resistant alleles, the Saglin-based gene drive reached high levels in caged mosquito populations and efficiently promoted the simultaneous spread of the antimalarial Lipophorin::Sc2A10 allele. 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.

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