MIVEGEC (CNRS UMR 5290), Centre de Recherche IRD Montpellier, France.
Evol Appl. 2013 Apr;6(3):497-509. doi: 10.1111/eva.12037. Epub 2012 Dec 11.
Because of their role as vectors of diseases, the evolution of insecticide resistance in mosquitoes has been intensively investigated. Insecticide resistance is associated to a wide range of pleiotropic effects on several key life-history traits of mosquitoes such as longevity and behavior. However, despite its potential implications in pathogen transmission, the effects of insecticide resistance on mosquito immunity have received little, if any, attention. Here, we investigate the impact of insecticide resistance in Culex pipiens, an epidemiologically important vector of a wide array of pathogens. Using both isogenic laboratory strains and field-caught mosquitoes, we investigate the impact of two main insecticide resistance mechanisms (metabolic detoxification and target site modification) on the relative transcription of several genes involved in the immune response to pathogens, at both their constitutive and inducible levels. Our results show a discrepancy between the isogenic laboratory lines and field-collected mosquitoes: While in the isogenic strains, insecticide-resistant mosquitoes show a drastic increase in immune gene expression, no such effect appears in the field. We speculate on the different mechanisms that may underlie this discrepancy and discuss the risks of making inferences on the pleiotropic effects of insecticide-resistant genes by using laboratory-selected insecticide-resistant lines.
由于蚊子作为疾病载体的作用，昆虫对杀虫剂的抗药性的进化受到了广泛关注。杀虫剂抗性与蚊子的许多关键生活史特征（如寿命和行为）的多种多效性有关。然而，尽管它可能对病原体传播有潜在影响，但杀虫剂抗性对蚊子免疫力的影响几乎没有受到关注。在这里，我们研究了杀虫剂抗性对库蚊（Culex pipiens）的影响，库蚊是多种病原体的重要流行病学传播媒介。我们使用同源的实验室菌株和野外捕获的蚊子，研究了两种主要的杀虫剂抗性机制（代谢解毒和靶位修饰）对病原体免疫反应相关基因的相对转录的影响，包括组成型和诱导型水平。我们的研究结果表明，在同源的实验室菌株和野外收集的蚊子之间存在差异：在同源的菌株中，抗杀虫剂的蚊子表现出免疫基因表达的急剧增加，但在野外没有出现这种效应。我们推测可能存在不同的机制导致了这种差异，并讨论了通过使用实验室选择的抗杀虫剂基因来推断抗杀虫剂基因的多效性效应的风险。
