Identification of a rapidly‐spreading triple mutant for high‐level metabolic insecticide resistance in Anopheles gambiae provides a real‐time molecular diagnostic for antimalarial intervention deployment

Abstract

Studies of insecticide resistance provide insights into the capacity of populations to show rapid evolutionary responses to contemporary selection. Malaria control remains heavily dependent on pyrethroid insecticides, primarily in long lasting insecticidal nets (LLINs). Resistance in the major malaria vectors has increased in concert with the expansion of LLIN distributions. Identifying genetic mechanisms underlying high-level resistance is crucial for the development and deployment of resistancebreaking tools. Using the Anopheles gambiae 1000 genomes (Ag1000g) data we identified a very recent selective sweep in mosquitoes from Uganda which localized to a cluster of cytochrome P450 genes. Further interrogation revealed a haplotype involving a trio of mutations, a nonsynonymous point mutation in Cyp6p4 (I236M), an upstream insertion of a partial Zanzibar-like transposable element (TE) and a duplication of the Cyp6aa1 gene. The mutations appear to have originated recently in An. gambiae

Genetic Diversity of Cytochrome P450s <em>CYP6M2</em> and <em>CYP6P4</em> Associated with Pyrethroid Resistance in the Major Malaria Vectors <em>Anopheles coluzzii</em> and <em>Anopheles </em><em>gambiae</em> from Yaoundé, Cameroon

“…In the full-gene region, one major amino-acid change at codon 168 where cysteine (C) is replaced by serine (S) were found in almost all the HR sequences. This amino-acid change was different from what has been seen in Uganda with the I 236 M mutation [20], with only the susceptible allele 236I found in all the An. coluzzii and An.…”

“…Such tools are less readily available for An. gambiae although, as described above, recently a triple mutant haplotype in CYP6P4 was linked to resistance in East Africa [20].…”

“…gambiae (7 HR, 7 HS, 7 Kisumu strain) respectively (Supplementary Figure S2). The nucleotide sequence analysis of this fragment exhibited a lower number of haplotype (8) and polymorphic sites (20) in An. coluzzii HR as compared to 14 haplotypes and 27 polymorphic sites in HS individuals (Table 2, Supplementary Figure S4).…”

“…arabiensis populations in the Sudano-Sahelian region [18,19]. Recently, Njoroge, et al [20] identified a selective sweep localized within a cluster of P450 genes including CYP6P4 in mosquitoes from Uganda. A haplotype, containing three mutations, I236M in CYP6P4, an upstream transposable element (TE) insertion and a CYP6AA1 duplication is strongly associated with pyrethroid resistance in An.…”

Genome-wide association studies reveal novel loci associated with pyrethroid and organophosphate resistance inAnopheles gambiaes.l.

“…The importance of Cyp6aa1 for deltamethrin resistance has been previously demonstrated in An. gambiae from East and Central Africa, where the CNV Cyp6aap_Dup1 was found to be associated with resistance and has spread rapidly (Njoroge et al, 2022). Similarly in our data, we found that copy number of Cyp6aa1 was associated with resistance in at least one population of An.…”