Larval midgut modifications associated with Bti resistance in the yellow fever mosquito using proteomic and transcriptomic approaches
Autor(es): Tetreau, Guillaume; Bayyareddy, Krishnareddy; Jones, Christopher M.; Stalinski, Renaud; Riaz, Muhammad A.; Paris, Margot; David, Jean-Philippe; Adang, Michael J.; Despres, Laurence
Resumo: Bacillus thuringiensis var. israelensis (Bti) is a natural larval mosquito pathogen producing pore-forming toxins targeting the midgut of Diptera larvae. It is used worldwide for mosquito control. Resistance mechanisms of an Aedes aegypti laboratory strain selected for 30 generations with field-collected leaf litter containing Bti toxins were investigated in larval midguts at two levels: 1. gene transcription using DNA microarray and RT-qPCR and 2. differential expression of brush border membrane proteins using DIGE (Differential In Gel Electrophoresis). Results: Several Bti Cry toxin receptors including alkaline phosphatases and N-aminopeptidases and toxin-binding V-ATPases exhibited altered expression levels in the resistant strain. The under-expression of putative Bti-receptors is consistent with Bt-resistance mechanisms previously described in Lepidoptera. Four soluble metalloproteinases were found under-transcribed together with a drastic decrease of metalloproteinases activity in the resistant strain, suggesting a role in resistance by decreasing the amount of activated Cry toxins in the larval midgut. Conclusions: By combining transcriptomic and proteomic approaches, we detected expression changes at nearly each step of the ingestion-to-infection process, providing a short list of genes and proteins potentially involved in Bti-resistance whose implication needs to be validated. Collectively, these results open the way to further functional analyses to better characterize Bti-resistance mechanisms in mosquitoes.
Palavras-Chave: Biological control; Leaf litter; Toxicants, Receptors; Transcription; Pest control; Pathogens; Strains; Chromium; Brush border membranes; DNA microarrays; Toxins; Gel electrophoresis; Metalloproteinase; Alkaline phosphatase; Yellow fever; Midgut; Proteomics
Imprenta: BMC Genomics, v. 13, n. 1, p. 248, 2012.
Descritores: Aedes aegypti - DNA ; Aedes aegypti - Proteins
Data de publicação: 2012
