Transcription profiling of resistance to Bti toxins in the mosquito Aedes aegypti using next-generation sequencing

J Invertebr Pathol. 2012 Feb;109(2):201-8. doi: 10.1016/j.jip.2011.11.004. Epub 2011 Nov 16.

Abstract

The control of mosquitoes transmitting infectious diseases relies mainly on the use of chemical insecticides. However, resistance to most chemical insecticides threatens mosquito control programs. In this context, the spraying of toxins produced by the bacteria Bacillus thuringiensis subsp. israelensis (Bti) in larval habitats represents an alternative to chemical insecticides and is now widely used for mosquito control. Recent studies suggest that resistance of mosquitoes to Bti toxin may occur locally but mechanisms have not been characterized so far. In the present study, we investigated gene transcription level variations associated with Bti toxin resistance in the mosquito Aedes aegypti using a next-generation sequencing approach. More than 6 million short cDNA tags were sequenced from larvae of two strains sharing the same genetic background: a Bti toxins-resistant strain and a susceptible strain. These cDNA tags were mapped with a high coverage (308 reads per position in average) to more than 6000 genes of Ae. aegypti genome and used to quantify and compare the transcription level of these genes between the two mosquito strains. Among them, 86 genes were significantly differentially transcribed more than 4-fold in the Bti toxins resistant strain comparatively to the susceptible strain. These included gene families previously associated with Bti toxins resistance such as serine proteases, alkaline phosphatase and alpha-amylase. These results are discussed in regards of potential Bti toxins resistance mechanisms in mosquitoes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / drug effects
  • Adaptation, Physiological / genetics
  • Aedes / drug effects*
  • Aedes / genetics
  • Animals
  • Bacillus thuringiensis / metabolism
  • Bacterial Toxins / pharmacology*
  • Biological Evolution
  • Female
  • Gene Expression Profiling*
  • Genes, Insect
  • Insecticide Resistance / drug effects*
  • Insecticide Resistance / genetics
  • Insecticides / pharmacology*
  • Larva / chemistry
  • Larva / drug effects
  • Larva / genetics
  • Male
  • Mosquito Control
  • Multigene Family
  • Pest Control, Biological
  • Selection, Genetic
  • Sequence Analysis, DNA

Substances

  • Bacterial Toxins
  • Insecticides