Epitranscriptomic regulation of insecticide resistance

N ⁶-methyladenosine (m⁶A) is the most prevalent messenger RNA modification in eukaryotes and an important posttranscriptional regulator of gene expression. However, the biological roles of m⁶A in most insects remain largely unknown. Here, we show that m⁶A regulates a cytochrome P450 gene (CYP4C64) in the global whitefly pest, Bemisia tabaci, leading to insecticide resistance. Investigation of the regulation of CYP4C64, which confers resistance to the insecticide thiamethoxam, revealed a mutation in the 5' untranslated region of this gene in resistant B. tabaci strains that introduces a predicted m⁶A site. We provide several lines of evidence that mRNA methylation of the adenine at this position, in combination with modified expression of m⁶A writers, acts to increase expression of CYP4C64 and resistance. Collectively, these results provide an example of the epitranscriptomic regulation of the xenobiotic response in insects and implicate the m⁶A regulatory axis in the development of insecticide resistance.