title: Investigating the genetics of Bti resistance using mRNA tag sequencing: application on laboratory strains and natural populations of the dengue vector Aedes aegypti.
abstract: Mosquito control is often the main method used to reduce mosquito-transmitted diseases. In order to investigate the genetic basis of resistance to the bio-insecticide Bacillus thuringiensis subsp. israelensis (Bti), we used information on polymorphism obtained from cDNA tag sequences from pooled larvae of laboratory Bti-resistant and susceptible Aedes aegypti mosquito strains to identify and analyse 1520 single nucleotide polymorphisms (SNPs). Of the 372 SNPs tested, 99.2% were validated using DNA Illumina GoldenGate® array, with a strong correlation between the allelic frequencies inferred from the pooled and individual data (r = 0.85). A total of 11 genomic regions and five candidate genes were detected using a genome scan approach. One of these candidate genes showed significant departures from neutrality in the resistant strain at sequence level. Six natural populations from Martinique Island were sequenced for the 372 tested SNPs with a high transferability (87%), and association mapping analyses detected 14 loci associated with Bti resistance, including one located in a putative receptor for Cry11 toxins. Three of these loci were also significantly differentiated between the laboratory strains, suggesting that most of the genes associated with resistance might differ between the two environments. It also suggests that common selected regions might harbour key genes for Bti resistance.
authors.affiliation: Laboratoire d'Ecologie Alpine (LECA), UMR 5553 CNRS-Université de Grenoble Grenoble, France ; Plant Ecological Genetics, Institute of Integrative Biology, ETH Zurich, Switzerland.
authors.forename: Margot
authors.initials: M
authors.lastname: Paris
authors.forename: Sebastien
authors.initials: S
authors.lastname: Marcombe
authors.forename: Eric
authors.initials: E
authors.lastname: Coissac
authors.forename: Vincent
authors.initials: V
authors.lastname: Corbel
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: David
authors.forename: Laurence
authors.initials: L
authors.lastname: Després
keywords: Aedes aegypti; Bacillus thurigiensis var. israelensis; RNAseq; genome scan; insecticide resistance; next-generation sequencing