Major Kaley M, Weston Donald P, Lydy Michael J, Huff Hartz Kara E, Wellborn Gary A, Manny Austin R, Poynton Helen C
School for the Environment University of Massachusetts Boston Massachusetts.
Present address: Department of Environmental and Molecular Toxicology Oregon State University Corvallis Oregon.
Evol Appl. 2019 Nov 27;13(4):620-635. doi: 10.1111/eva.12888. eCollection 2020 Apr.
Organophosphate (OP) and carbamate (CM) insecticides are widely used in the United States and share the same mode of toxic action. Both classes are frequently documented in aquatic ecosystems, sometimes at levels that exceed aquatic life benchmarks. We previously identified a population of the nontarget amphipod, , thriving in an agricultural creek with high sediment levels of the OP chlorpyrifos, suggesting the population may have acquired genetic resistance to the pesticide. In the present study, we surveyed 17 populations of in California to screen for phenotypic resistance to chlorpyrifos as well as genetic signatures of resistance in the acetylcholinesterase (-1) gene. We found no phenotypic chlorpyrifos resistance in populations from areas with little or no pesticide use. However, there was ~3- to 1,000-fold resistance in populations from agricultural and/or urban areas, with resistance levels in agriculture being far higher than urban areas due to greater ongoing use of OP and CM pesticides. In every case of resistance in , we identified a glycine-to-serine amino acid substitution (G119S) that has been shown to confer OP and CM resistance in mosquitoes and has been associated with resistance in other insects. We found that the G119S mutation was always present in a heterozygous state Further, we provide tentative evidence of an -1 gene duplication in that may play a role in chlorpyrifos resistance in some populations. The detection of a genetically based, adaptive OP and CM resistance in some of the same populations of previously shown to harbor a genetically based adaptive pyrethroid resistance indicates that these nontarget amphipod populations have become resistant to many of the insecticides now in common use. The terrestrial application of pesticides has provided strong selective pressures to drive evolution in a nontarget, aquatic species.
有机磷酸酯（OP）和氨基甲酸酯（CM）类杀虫剂在美国广泛使用，且具有相同的毒性作用模式。这两类杀虫剂在水生生态系统中经常被检测到，有时其含量超过了水生生物基准水平。我们之前发现，在一条农业溪流中，非靶标双足节肢动物种群在毒死蜱沉积物含量很高的环境中繁衍生息，这表明该种群可能已获得对这种杀虫剂的遗传抗性。在本研究中，我们调查了加利福尼亚州的17个双足节肢动物种群，以筛选对毒死蜱的表型抗性以及乙酰胆碱酯酶（AChE-1）基因中的抗性遗传特征。我们发现，在几乎没有或未使用杀虫剂地区的种群中，没有对毒死蜱的表型抗性。然而，来自农业和/或城市地区的双足节肢动物种群具有约3至1000倍的抗性，由于OP和CM类杀虫剂的持续使用量更大，农业地区的抗性水平远高于城市地区。在每一例双足节肢动物抗性案例中，我们都发现了甘氨酸到丝氨酸的氨基酸替换（G119S），该替换已被证明可使蚊子对OP和CM产生抗性，并且与其他昆虫的抗性有关。我们发现G119S突变总是以杂合状态存在。此外，我们提供了初步证据，表明双足节肢动物中存在AChE-1基因重复，这可能在某些种群对毒死蜱的抗性中起作用。在之前已显示具有基于遗传的适应性拟除虫菊酯抗性的一些相同双足节肢动物种群中，检测到基于遗传的适应性OP和CM抗性，这表明这些非靶标双足节肢动物种群已对许多目前常用的杀虫剂产生抗性。农药的地面施用为推动非靶标水生物种的进化提供了强大的选择压力。
