Synergistic and compensatory effects of two point mutations conferring target-site resistance to fipronil in the insect GABA receptor RDL.
Synergistic and compensatory effects of two point mutations conferring target-site resistance to fipronil in the insect GABA receptor RDL.
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DOI：
10.1038/srep32335
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发表时间：
2016-08-25
影响因子：
4.6
通讯作者：
Liu Z
中科院分区：
文献类型：
--
作者：
Zhang Y;Meng X;Yang Y;Li H;Wang X;Yang B;Zhang J;Li C;Millar NS;Liu Z
杀虫剂抗药性可由多种机制引起，包括目标部位的改变，但往往与昆虫的大量适应成本有关。在这里，我们描述了两个与抗药性相关的靶点突变，它们具有协同和补偿效应，结合在一起产生了对氟虫腈的高水平和持久的抗药性，氟虫腈是一种靶向γ-氨基丁酸受体的杀虫剂。在亚洲许多地区的主要水稻害虫褐飞虱中，我们已经在GABA受体RDL中发现了一个单点突变(A302S)，该突变在其他物种中已被发现，并使褐飞虱对氟虫腈的抗性水平较低(23倍)。此外，我们还发现了第二个与耐药性相关的RDL突变(R300Q)，与A302S结合，与更高水平的耐药性(237倍)有关。在实验室选择的人群或现场人群中，在没有A302S的情况下都没有检测到R300Q突变，可能是因为与该突变相关的高适应成本。值得注意的是，A302S突变似乎能够补偿R300Q突变对健康成本的有害影响。这些发现确定了一种新的抗性机制，并可能对杀虫剂耐药性的传播具有重要意义。
Insecticide resistance can arise from a variety of mechanisms, including changes to the target site, but is often associated with substantial fitness costs to insects. Here we describe two resistance-associated target-site mutations that have synergistic and compensatory effects that combine to produce high and persistent levels of resistance to fipronil, an insecticide targeting on γ-aminobytyric acid (GABA) receptors. In Nilaparvata lugens, a major pest of rice crops in many parts of Asia, we have identified a single point mutation (A302S) in the GABA receptor RDL that has been identified previously in other species and which confers low levels of resistance to fipronil (23-fold) in N. lugans. In addition, we have identified a second resistance-associated RDL mutation (R300Q) that, in combination with A302S, is associated with much higher levels of resistance (237-fold). The R300Q mutation has not been detected in the absence of A302S in either laboratory-selected or field populations, presumably due to the high fitness cost associated with this mutation. Significantly, it appears that the A302S mutation is able to compensate for deleterious effects of R300Q mutation on fitness cost. These findings identify a novel resistance mechanism and may have important implications for the spread of insecticide resistance.