HighWolbachiadensity in insecticide–resistant mosquitoes

• DOI: 10.1098/rspb.2002.2022
• Publication Date: 2002-07-28T22:41:28Z
• Authors: Claire Berticat; François Rousset; Michel Raymond; Arnaud Berthomieu; Mylène Weill
• Keywords: Insecticides; 0303 health sciences; [SDV]Life Sciences [q-bio]; Colony Count, Microbial; Genes, Insect; Fitness Cost; Endocellular Bacteria; Polymerase Chain Reaction; 3. Good health; [SDV] Life Sciences [q-bio]; Insecticide Resistance; Culex; 03 medical and health sciences; Insecticidal Resistance; Animals; Symbiosis; Wolbachia

Wolbachia symbionts are responsible for various alterations in host reproduction. The effects of the host genome on endosymbiont levels have often been suggested, but rarely described. Here, we show that Wolbachia density is strongly modified by the presence of insecticide-resistant genes in the common house mosquito, Culex pipiens. The Wolbachia density was estimated using a real-time quantitative PCR assay. Strains harbouring different genes conferring resistance were more infected than a susceptible strain with the same genetic background. We show that this interaction also operates in natural populations. We propose that mosquitoes may control Wolbachia density less efficiently when they carry an insecticide-resistant gene, i.e. when they suffer from a physiological resistance cost.