Insecticide use is pervasive as a selective force in modern agroecosystems. Insect herbivores exposed to these insecticides have been able to rapidly evolve resistance to them, but how they are able to do so is poorly understood. One possible but largely unexplored explanation is that exposure to sublethal doses of insecticides may alter epigenetic patterns that are heritable. For instance, epigenetic mechanisms, such as DNA methylation that modifies gene expression without changing the underlying genetic code, may facilitate the emergence of resistant phenotypes in complex ways. We assessed the effects of sublethal insecticide exposure, with the neonicotinoid imidacloprid, on DNA methylation in the Colorado potato beetle, Leptinotarsa decemlineata, examining both global changes in DNA methylation and specific changes found within genes and transposable elements. We found that exposure to insecticide led to decreases in global DNA methylation for parent and F2 generations and that many of the sites of changes in methylation are found within genes associated with insecticide resistance, such as cytochrome P450s, or within transposable elements. Exposure to sublethal doses of insecticide caused heritable changes in DNA methylation in an agricultural insect herbivore. Therefore, epigenetics may play a role in insecticide resistance, highlighting a fundamental mechanism of evolution while informing how we might better coexist with insect species in agroecosystems.

中文翻译：

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杀虫剂暴露影响科罗拉多马铃薯甲虫 Leptinotarsa decemlineata 的 DNA 甲基化代际模式


杀虫剂的使用作为现代农业生态系统中的一种选择力量是普遍存在的。接触这些杀虫剂的昆虫食草动物能够迅速进化出对它们的抗药性，但人们对它们如何做到这一点却知之甚少。一种可能但很大程度上尚未探索的解释是，接触亚致死剂量的杀虫剂可能会改变可遗传的表观遗传模式。例如，表观遗传机制，例如在不改变潜在遗传密码的情况下修改基因表达的DNA甲基化，可能会以复杂的方式促进耐药表型的出现。我们评估了新烟碱类吡虫啉接触亚致死杀虫剂对科罗拉多马铃薯甲虫Leptinotarsa decemlineata DNA 甲基化的影响，检查了 DNA 甲基化的整体变化以及基因和转座元件内发现的特定变化。我们发现接触杀虫剂会导致亲代和 F2 代的整体 DNA 甲基化降低，并且许多甲基化变化位点存在于与杀虫剂抗性相关的基因（例如细胞色素 P450）或转座元件内。接触亚致死剂量的杀虫剂会导致农业昆虫草食动物的 DNA 甲基化发生遗传性变化。因此，表观遗传学可能在杀虫剂抗性中发挥作用，强调进化的基本机制，同时告诉我们如何更好地与农业生态系统中的昆虫物种共存。