xenobiotic response in Aedes aegypti larvae using illumina-solexa DGETP method
Transcriptome-wide analysis of response to insecticides and pollutants in                 the yellow fever mosquito using next-generation sequencing technology
Background: The control of mosquitoes transmitting infectious diseases                 relies mainly on the use of chemical insecticides. However, mosquito control                 programs are now threatened by the emergence of insecticide resistance mechanisms.                 Hitherto, most research efforts have been focused on elucidating molecular basis of                 inherited resistance, but less attention has been paid to the short-term response of                 mosquitoes to insecticides and pollutants and yet this could have a significant                 impact on insecticide efficacy and may allow identifying mosquito genes involved in                 insecticide tolerance. Here, a combination of LongSAGE and Solexa sequencing was                 used to perform a deep transcriptome analysis of larvae of the yellow fever mosquito                 exposed for 48h to sub-lethal doses of three chemical insecticides and three                 anthropogenic pollutants. Results: Thirty millions of 20 bp cDNA tags were                 sequenced, mapped to mosquito genome and clustered, representing 6850 known genes                 and 4868 additional clusters not located within predicted genes. Differential                 transcriptome analysis revealed 453 genes and 250 additional clusters being                 differentially transcribed in mosquito larvae exposed to xenobiotics.                 Cross-validation of transcription profiles of 14 selected genes by RT-qPCR revealed                 a high correlation of transcription ratios obtained from the two techniques.                 Mosquitoes exposed to insecticides or anthropogenic pollutants showed considerable                 modifications of their transcriptome correlated to the molarity and chemical                 properties of xenobiotics. Genes encoding cuticular proteins, transporters, and                 enzymes involved in the mitochondrial respiratory chain and detoxification processes                 were particularly affected. Conclusion: Genes and molecular mechanisms potentially                 involved in xenobiotic response and insecticide tolerance were identified. Despite                 low concentrations and no apparent phenotypic effects, the significant impact of                 these xenobiotics on mosquito larvae transcriptome rise important questions about                 the ?hidden impact? of anthropogenic pollutants on ecosystems and consequences on                 vector control in polluted areas. At the technical level, the method used in the                 present study appears as a powerful approach for investigating transcriptome                 variations in genome-sequenced organisms and can provide useful informations for the                 detection of novel transcripts.