Project description:This microarray study aimed at evaluating the impact of mosquito chemical environment on the selection of insecticide resistance mechanisms. Here the mosquito Aedes aegypti was used as a model to perform a laboratory experiment combining mosquito larvae exposure to a sub-lethal dose of xenobiotic and their selection with the insecticide permethrin. After ten generations, bioassays and a transcriptome profiling with the 15K microarray Aedes detox chip plus microarray were performed comparatively on all strains.
Project description:This microarray study aimed at comparing constitutive gene expression levels between an Aedes aegypti insecticide-resistant strain (Imida-R) selected at the larval stage with the neonicotinoid insecticide imidacloprid for 10 generations and the parental strain (Bora-Bora) susceptible to all insecticides. Strains comparison was performed at both larval (4th stage larvae) and adult (3 days-old adults females, non-blood fed) stages.
Project description: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 polymorphismvariations associatedwith resistance to each Bti Cry toxin and to the full Bti toxin mixture in the dengue vector Aedes aegypti. The upregulation of genes related to chitin metabolismin 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 resistancewere detected in 2 ALP and 1 APNgenes. 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.
Project description:This microarray experiment aimed at studying the response of Aedes aegypti 4th stage-larvae to various xenobiotics, including insecticides, polycyclic aromatic hydrocarbons, herbicides and heavy metals.
Project description:This study aimed at comparing gene transcription using microarrays and protein expression using 2D-DIGE between an Aedes aegypti insecticide-resistant strain (LiTOX) selected for 28 generations at the larval stage with field-collected leaf litter containing persistent Bacillus thuringiensis var. israelensis (Bti) toxins and the parental strain (Bora-Bora) susceptible to all insecticides. We focused on the tissue where the mode of action of the insecticide takes place: the midgut of the larvae.
Project description:Transcriptome profiling of two pyrethroid resistant strains of Aedes aegypti compared to a susceptible strain. The two resistant strains are from Cuba and Cayman Island and the susceptible strain from New Orleans.
Project description:Transcriptome profiling of pyrethroid resistant field populations of Anopheles funestus from Malawi and Mozambique compared to a susceptible lab strain FANG
Project description:The aim of this experiment was to compare the transciptome of the fall armyworm (Spodoptera frugiperda) strain SUS (a laboratory insecticide-susceptible standard) with organophosphate (OP) and pyrethroid (PYR) resistant strains were collected in cornfields located in Minas Gerais and Mato Grosso States, Brazil, in 2008 and maintained in the laboratory under selection with chlorpyrifos (at increasing discriminating doses from 100 up to 400 M-BM-5g of insecticide/g of insect in a topical bioassay) or lambda-cyhalothrin (from 8.4 up to 27 M-BM-5g of insecticide/g of insect) respectively The custom microarray used in this study was designed using the Agilent eArray platform (Agilent Technologies). A SurePrint HD (8M-CM-^W15k) expression array was designed using the base composition and the best probe methodologies to design sense orientation 60-mer probes with a 3M-bM-^@M-2 bias. The FAW EST database (SPODOBASE) was used as the reference transcriptome (Negre, Hotelier et al. 2006). These sequences are derived from 8 cDNA libraries as follows: Sf1F: Fat body, Sf1H: Hemocyte, Sf1M: Midgut, Sf1P: Pool of various tissues, Sf2H: Immune Challenged hemocytes, Sf2L: Sf21 Cell lines sequences, Sf2M: Xenobiotic Induced Midgut and Sf9L: Sf9 cell lines sequences. All assembled contigs and singlets were kindly sent by the website maintainers. The BLAST2GO software v.2.3.1 (http://www.blast2go.org) was used to annotate the EST database. 60-mer probes were designed for all 7,552 assembled contigs and 5,519 annotated singlets (BlastX), totaling 13,071 sequences. For contigs encoding detoxification enzymes (P450s, GSTs and CEs) three probes were designed. Additional probe groups for 15 control genes were also included. For reference all sequences are included in the zip file with array data. References: Negre, V., T. Hotelier, et al. (2006). "SPODOBASE : an EST database for the lepidopteran crop pest Spodoptera." BMC Bioinformatics 7: 322. Two-condition experiment. Slide 1: SUS vs. OP S. fugiperda strains. Slide 2: SUS vs. PYR S. fugiperda strains. Biological replicates: 4 pools of RNA extracted from four pools of 5 second instar larvae. Technical Replicates: None, the biological replicates incorporated a dye swap. Total replication: four replicates for each strain.
Project description:The transcriptional profile of pyrethroid resistant Anopheles arabiensis from Zanzibar. Anopheles arabiensis from Pemba Island, exposed (Survivors) and non-exposed (Pemba) to a discriminating dose of the pyrethroid lambda-cyhalothrin were compared to two insecticide susceptible strains from Zanzibar island (Unguja) and Dar es Salaam (Dar).