Evolution of the insecticide targetRdlin AfricanAnophelesis driven by interspecific and interkaryotypic introgression

Abstract

AbstractThe evolution of insecticide resistance mechanisms in natural populations ofAnophelesmalaria vectors is a major public health concern across Africa. Using genome sequence data, we study the evolution of resistance mutations in theresistance to dieldrin locus(Rdl), a GABA receptor targeted by several insecticides, but most notably by the long-discontinued cyclodiene, dieldrin. The twoRdlresistance mutations (296Gand296S) spread across West and Central AfricanAnophelesvia two independent hard selective sweeps that included likely compensatory nearby mutations, and were followed by a rare combination of introgression across species (fromA. gambiaeandA. arabiensistoA. coluzzii) and across non-concordant karyotypes of the 2La chromosomal inversion.Rdlresistance evolved in the 1950s as the first known adaptation to a large-scale insecticide-based intervention, but the evolutionary lessons from this system highlight contemporary and future dangers for management strategies designed to combat development of resistance in malaria vectors.