Cohen Zachary P, Chen Yolanda H, Groves Russell, Schoville Sean D
Department of Entomology University of Wisconsin-Madison Madison Wisconsin USA.
Department of Plant and Soil Sciences University of Vermont Burlington Vermont USA.
Evol Appl. 2022 Oct 25;15(10):1691-1705. doi: 10.1111/eva.13498. eCollection 2022 Oct.
Pesticide resistance provides one of the best examples of rapid evolution to environmental change. The Colorado potato beetle (CPB) has a long and noteworthy history as a super-pest due to its ability to repeatedly develop resistance to novel insecticides and rapidly expand its geographic and host plant range. Here, we investigate regional differences in demography, recombination, and selection using whole-genome resequencing data from two highly resistant CPB populations in the United States (Hancock, Wisconsin and Long Island, New York). Demographic reconstruction corroborates historical records for a single pest origin during the colonization of the Midwestern and Eastern United States in the mid- to late-19th century and suggests that the effective population size might be higher in Long Island, NY than Hancock, WI despite contemporary potato acreage of Wisconsin being far greater. Population-based recombination maps show similar background recombination rates between these populations, as well as overlapping regions of low recombination that intersect with important metabolic detoxification genes. In both populations, we find compelling evidence for hard selective sweeps linked to insecticide resistance with multiple sweeps involving genes associated with xenobiotic metabolism, stress response, and defensive chemistry. Notably, only two candidate insecticide resistance genes are shared among both populations, but both appear to be independent hard selective sweep events. This suggests that repeated, rapid, and independent evolution of genes may underlie CPB's pest status among geographically distinct populations.
抗药性是环境变化导致快速进化的最佳例证之一。科罗拉多马铃薯甲虫（CPB）作为一种超级害虫，有着悠久且引人注目的历史，因为它能够反复对新型杀虫剂产生抗性，并迅速扩大其地理分布范围和寄主植物范围。在此，我们利用来自美国两个高度抗药的CPB种群（威斯康星州汉考克和纽约州长岛）的全基因组重测序数据，研究了种群统计学、重组和选择方面的区域差异。种群统计学重建证实了19世纪中后期美国中西部和东部殖民时期单一害虫起源的历史记录，并表明尽管威斯康星州目前的马铃薯种植面积远大于纽约州长岛，但纽约州长岛的有效种群规模可能高于威斯康星州的汉考克。基于种群的重组图谱显示，这些种群之间的背景重组率相似，以及与重要代谢解毒基因相交的低重组重叠区域。在这两个种群中，我们都发现了与抗药性相关的强烈硬选择扫荡证据，多个扫荡涉及与异生物质代谢、应激反应和防御化学相关的基因。值得注意的是，两个种群中仅共享两个候选抗药性基因，但两者似乎都是独立的硬选择扫荡事件。这表明基因的反复、快速和独立进化可能是CPB在地理上不同种群中成为害虫的基础。
