title: Receptors are affected by selection with each Bacillus thuringiensis israelensis Cry toxin but not with the full Bti mixture in Aedes aegypti.
abstract: Bacillus thuringiensis israelensis (Bti) toxins are increasingly used for mosquito control, but little is known about the precise mode of action of each of these toxins, and how they interact to kill mosquito larvae. By using RNA sequencing, we investigated change in gene transcription level and polymorphism variations associated with resistance to each Bti Cry toxin and to the full Bti toxin mixture in the dengue vector Aedes aegypti. The up-regulation of genes related to chitin metabolism in all selected strain suggests a generalist, non-toxin-specific response to Bti selection in Aedes aegypti. Changes in the transcription level and/or protein sequences of several putative Cry toxin receptors (APNs, ALPs, α-amylases, glucoside hydrolases, ABC transporters) were specific to each Cry toxin. Selective sweeps associated with Cry4Aa resistance were detected in 2 ALP and 1 APN genes. The lack of selection of toxin-specific receptors in the Bti-selected strain supports the hypothesis that Cyt toxin acts as a receptor for Cry toxins in mosquitoes.
authors.affiliation: Université Grenoble Alpes, Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France; Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Stalinski
authors.affiliation: Université Grenoble Alpes, Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France; Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Laporte
authors.affiliation: Université Grenoble Alpes, Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France; Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Tetreau
authors.affiliation: Université Grenoble Alpes, Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France; Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie Alpine UMR5553, F-38000 Grenoble, France. Electronic address: Laurence.despres@ujf-grenoble.fr.
authors.forename: Laurence
authors.initials: L
authors.lastname: Després
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000235:genetics*; D000469:Alkaline Phosphatase / Q000235:genetics; D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000494:pharmacology*; D018826:CD13 Antigens / Q000235:genetics; D002686:Chitin / Q000235:genetics / Q000378:metabolism; D004731:Endotoxins / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006460:Hemolysin Proteins / Q000494:pharmacology; D019476:Insect Proteins / Q000235:genetics*; D007305:Insecticide Resistance / Q000187:drug effects / Q000235:genetics*; D007814:Larva / Q000187:drug effects / Q000235:genetics; D000072138:Mosquito Vectors / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D011956:Receptors, Cell Surface
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; C095416:Cry toxin receptors; D004731:Endotoxins; D006460:Hemolysin Proteins; D019476:Insect Proteins; D011956:Receptors, Cell Surface; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D002686:Chitin; D000469:Alkaline Phosphatase; D018826:CD13 Antigens
keywords: Bacillus thuringiensis israelensis toxins; Bio-insecticide resistance; Mosquito; RNA-seq; Single Nucleotide Polymorphism; Specific receptors