title: Alkaline phosphatases are involved in the response of Aedes aegypti larvae to intoxication with Bacillus thuringiensis subsp. israelensis Cry toxins.
abstract: Bacillus thuringiensis subsp. israelensis (Bti) is a natural pathogen of dipterans widely used as a biological insecticide for mosquito control. To characterize the response of mosquitoes to intoxication with Bti, the transcriptome profile of Bti-exposed susceptible Aedes aegypti larvae was analysed using Illumina RNA-seq. Gene expression of 11 alkaline phosphatases (ALPs) was further investigated by real time quantitative polymerase chain reaction and ALP activity was measured in the susceptible strain and in four strains resistant to a single Bti Cry toxin or to Bti. These strains were unexposed or exposed to their toxin of selection. Although all resistant strains constitutively exhibited a higher level of transcription of ALP genes than the susceptible strain, they showed a lower total ALP activity. The intoxication with different individual Cry toxins triggered a global pattern of ALP gene under-transcription in all the one-toxin-resistant strains but involving different specific sets of ALPs in each resistant phenotype. Most of the ALPs involved are not known Cry-binding proteins. RNA interference experiment demonstrated that reducing ALP expression conferred increased the survival of larvae exposed to Cry4Aa, confirming the involvement of ALP in Cry4Aa toxicity.
authors.affiliation: Laboratoire d'Ecologie Alpine LECA UMR5553, Université Grenoble Alpes, F-38000, Grenoble, France.|Laboratoire d'Ecologie Alpine LECA UMR5553, Centre National de la Recherche Scientifique, F-38000, Grenoble, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Stalinski
authors.affiliation: Laboratoire d'Ecologie Alpine LECA UMR5553, Université Grenoble Alpes, F-38000, Grenoble, France.|Laboratoire d'Ecologie Alpine LECA UMR5553, Centre National de la Recherche Scientifique, F-38000, Grenoble, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Laporte
authors.affiliation: Laboratoire d'Ecologie Alpine LECA UMR5553, Université Grenoble Alpes, F-38000, Grenoble, France.|Laboratoire d'Ecologie Alpine LECA UMR5553, Centre National de la Recherche Scientifique, F-38000, Grenoble, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Després
authors.affiliation: Laboratoire d'Ecologie Alpine LECA UMR5553, Université Grenoble Alpes, F-38000, Grenoble, France.|Laboratoire d'Ecologie Alpine LECA UMR5553, Centre National de la Recherche Scientifique, F-38000, Grenoble, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Tetreau
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000235:genetics / Q000382:microbiology; D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000494:pharmacology*; D004731:Endotoxins / Q000494:pharmacology*; D006460:Hemolysin Proteins / Q000494:pharmacology*; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects* / Q000235:genetics / Q000382:microbiology; D008969:Molecular Sequence Data; D009032:Mosquito Control / Q000379:methods; D010641:Phenotype; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D059467:Transcriptome
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; D034741:RNA, Small Interfering; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D000469:Alkaline Phosphatase