School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, 3010, Australia.
School of Chemistry, Bio21 Institute of Molecular Science and Biotechnology, and ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Melbourne, Melbourne, Victoria, 3010, Australia.
Sci Rep. 2017 Sep 12;7(1):11338. doi: 10.1038/s41598-017-11092-5.
Insecticide resistance is an economically important example of evolution in response to intense selection pressure. Here, the genetics of resistance to the neonicotinoid insecticide imidacloprid is explored using the Drosophila Genetic Reference Panel, a collection of inbred Drosophila melanogaster genotypes derived from a single population in North Carolina. Imidacloprid resistance varied substantially among genotypes, and more resistant genotypes tended to show increased capacity to metabolize and excrete imidacloprid. Variation in resistance level was then associated with genomic and transcriptomic variation, implicating several candidate genes involved in central nervous system function and the cytochrome P450s Cyp6g1 and Cyp6g2. CRISPR-Cas9 mediated removal of Cyp6g1 suggested that it contributed to imidacloprid resistance only in backgrounds where it was already highly expressed. Cyp6g2, previously implicated in juvenile hormone synthesis via expression in the ring gland, was shown to be expressed in metabolically relevant tissues of resistant genotypes. Cyp6g2 overexpression was shown to both metabolize imidacloprid and confer resistance. These data collectively suggest that imidacloprid resistance is influenced by a variety of previously known and unknown genetic factors.
杀虫剂抗性是对强烈选择压力产生进化的一个重要经济实例。在这里，使用果蝇遗传参考面板（一个源自北卡罗来纳州单一群体的近交果蝇基因型的集合）探索了对新烟碱类杀虫剂吡虫啉的抗性的遗传学。吡虫啉抗性在基因型之间存在很大差异，更具抗性的基因型往往表现出增加代谢和排泄吡虫啉的能力。抗性水平的变化与基因组和转录组变化相关，涉及几个参与中枢神经系统功能和细胞色素 P450s Cyp6g1 和 Cyp6g2 的候选基因。CRISPR-Cas9 介导的 Cyp6g1 去除表明，它仅在 Cyp6g1 已经高度表达的背景下才有助于吡虫啉抗性。先前通过在环腺中的表达而与保幼激素合成有关的 Cyp6g2 被证明在抗性基因型的代谢相关组织中表达。过表达 Cyp6g2 既可以代谢吡虫啉又可以赋予抗性。这些数据共同表明，吡虫啉抗性受多种先前已知和未知的遗传因素影响。
