Next-generation gene drive for population modification of the malaria vector mosquito, <i>Anopheles gambiae</i>

TLDR

The study develops a Cas9/guide RNA-based gene drive strain, AgNosCd‑1, to deliver antiparasite effector molecules into Anopheles gambiae. The drive targets the cardinal gene ortholog, producing a red‑eye phenotype, and was engineered to achieve high transmission efficiency. In cage trials, AgNosCd‑1 achieved 98–100% drive in both sexes within 6–10 generations, exhibited negligible genetic load, low resistance allele frequency (<0.1), minimal off‑target activity, and met key performance criteria for a field‑ready malaria‑control strain.

Abstract

A Cas9/guide RNA-based gene drive strain, AgNosCd-1, was developed to deliver antiparasite effector molecules to the malaria vector mosquito, Anopheles gambiae The drive system targets the cardinal gene ortholog producing a red-eye phenotype. Drive can achieve 98 to 100% in both sexes and full introduction was observed in small cage trials within 6 to 10 generations following a single release of gene-drive males. No genetic load resulting from the integrated transgenes impaired drive performance in the trials. Potential drive-resistant target-site alleles arise at a frequency <0.1, and five of the most prevalent polymorphisms in the guide RNA target site in collections of colonized and wild-derived African mosquitoes do not prevent cleavage in vitro by the Cas9/guide RNA complex. Only one predicted off-target site is cleavable in vitro, with negligible deletions observed in vivo. AgNosCd-1 meets key performance criteria of a target product profile and can be a valuable component of a field-ready strain for mosquito population modification to control malaria transmission.