Transcriptome response to pollutants and insecticides in the dengue vector Aedes aegypti 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. Hitherto, most research efforts have been focused on elucidating the molecular basis of inherited resistance. Less attention has been paid to the short-term response of mosquitoes to insecticides and pollutants which could have a significant impact on insecticide efficacy. Here, a combination of LongSAGE and Solexa sequencing was used to perform a deep transcriptome analysis of larvae of the dengue vector Aedes aegypti exposed for 48 h to sub-lethal doses of three chemical insecticides and three anthropogenic pollutants.


RESULTS
Thirty millions 20 bp cDNA tags were sequenced, mapped to the mosquito genome and clustered, representing 6850 known genes and 4868 additional clusters not located within predicted genes. Mosquitoes exposed to insecticides or anthropogenic pollutants showed considerable modifications of their transcriptome. Genes encoding cuticular proteins, transporters, and enzymes involved in the mitochondrial respiratory chain and detoxification processes were particularly affected. Genes and molecular mechanisms potentially involved in xenobiotic response and insecticide tolerance were identified.


CONCLUSIONS
The method used in the present study appears as a powerful approach for investigating fine transcriptome variations in genome-sequenced organisms and can provide useful informations for the detection of novel transcripts. At the biological level, despite low concentrations and no apparent phenotypic effects, the significant impact of these xenobiotics on mosquito transcriptomes raise important questions about the 'hidden impact' of anthropogenic pollutants on ecosystems and consequences on vector control.
David
Jean-Philippe
JP
Laboratoire d'Ecologie Alpine (LECA, UMR 5553 CNRS-Université Grenoble), France. jean-philippe.david@ujf-grenoble.fr
Coissac
Eric
E
Melodelima
Christelle
C
Poupardin
Rodolphe
R
Riaz
Muhammad Asam
MA
Chandor-Proust
Alexia
A
Reynaud
Stéphane
S
D000330:Aedes / Q000187:drug effects*; D000818:Animals; D004785:Environmental Pollutants / Q000494:pharmacology*; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000032:analysis*; D007306:Insecticides / Q000494:pharmacology*; D015262:Xenobiotics / Q000494:pharmacology
D004785:Environmental Pollutants; D019476:Insect Proteins; D007306:Insecticides; D015262:Xenobiotics