World‐wide survey of anAccordinsertion and its association with DDT resistance inDrosophila melanogaster

Abstract

Previous work showed that insecticide resistance in Drosophila melanogaster is correlated with the insertion of an Accord-like element into the 5' region of the cytochrome P450 gene, Cyp6g1. Here, we study the distribution of the Accord-like element in 673 recently collected D. melanogaster lines from 34 world-wide populations. We also examine the extent of microsatellite variability along a 180-kilobase (kb) genomic region of chromosome II encompassing the resistance gene. We confirm a 100% correlation of the Accord insertion with insecticide resistance and a significant reduction in variability extending at least 20 kb downstream of the Cyp6g1 gene. The frequency of the Accord insertion differs significantly between East African (32-55%) and nonAfrican (85-100%) populations. This pattern is consistent with a selective sweep driving the Accord insertion close to fixation in nonAfrican populations as a result of the insecticide resistance phenotype it confers. This study confirms that hitchhiking mapping can be used to identify beneficial mutations in natural populations.

A cis-regulatory sequence driving metabolic insecticide resistance in mosquitoes: Functional characterisation and signatures of selection

“…(Catania et al, 2004;Karasov et al, 2010;Lynd et al, 2010;Saminadin-Peter et al, 2012). Through cloning and sequencing of the region upstream of CYP9M10 in field populations we have shown that sequence identical to that found in the ISOP450 strain can be found in Ghana, Malawi, Zambia and Uganda.…”

“…Through cloning and sequencing of the region upstream of CYP9M10 in field populations we have shown that sequence identical to that found in the ISOP450 strain can be found in Ghana, Malawi, Zambia and Uganda. This suggests not only a ubiquitous pan-African distribution of the resistant allele but also a recent selective sweep (Lynd et al, 2010), which mirrors the situation for Drosophila CYP6g1 where a selective sweep is indicated from worldwide sampling (Catania et al, 2004;Schlenke and Begun, 2004). A consequence of the selective sweep is that…”

“…Perhaps the best described example of a TE inserted close to a functional CYP450 is CYP6g1 in Drosophila melanogaster which confers resistance to DDT and for which the allele containing the TE now has a worldwide distribution (Brookfield, 2004;Catania et al, 2004;Daborn et al, 2002;Schlenke and Begun, 2004; Schmidt et al, 2010). In the CYP450 family generally, transposable elements are over-represented in proximity to insect CYP450s involved in metabolic detoxification whilst being largely absent from CYP450s Via crossing and selection, kdr-mediated resistance was removed such that permethrin resistance in ISOP450 is mediated solely by metabolic resistance.…”

Genomic regions harboring insecticide resistance-associated Cyp genes are enriched by transposable element fragments carrying putative transcription factor binding sites in two sibling Drosophila species

“…Cyp4e2 (Amichot et al, 1994), Cyp6a2 (Maitra et al, 1996(Maitra et al, , 2000Pedra et al, 2004), Cyp6a8 (Maitra et al, 2000), Cyp6a9 (Maitra et al, 1996), Cyp6g1 (Catania et al, 2004;Daborn et al, 2002;Schlenke and Begun, 2004), Cyp6w1 (Pedra et al, 2004), Cyp12a4 (Bogwitz et al, 2005), Cyp12d1 (Brandt et al, 2002) and Cyp308a1 (Gene Ontology Consortium, 2001). Six of these genes have been associated with high levels of gene transcription in resistant insects (Amichot et al, 2004;Bogwitz et al, 2005;Daborn et al, 2002Daborn et al, , 2007Helvig et al, 2004;Le Goff et al, 2003).…”

“…Daborn et al (2002) reported that the insecticide resistance mapping to the DDT-R locus of D. melanogaster is due to the over-expression of one gene, Cyp6g1, and that a single Cyp6g1 allele linked to this resistance is distributed worldwide. Unlike other insecticide resistance genes in which overexpression is associated with point mutations, over-expression of Cyp6g1is characterized by the insertion of a fragment of the Accord retrotransposon upstream of the gene (Catania et al, 2004;Chung et al, 2007;Daborn et al, 2002). Schlenke and Begun (2004) have also reported an association between a TE insertion and insecticide resistance in Drosophila simulans.…”