Population bulk segregant mapping uncovers resistance mutations and the mode of action of a chitin synthesis inhibitor in arthropods
Population bulk segregant mapping uncovers resistance mutations and the mode of action of a chitin synthesis inhibitor in arthropods
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DOI：
10.1073/pnas.1200068109
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发表时间：
2012-03-20
影响因子：
11.1
通讯作者：
Clark, Richard M.
中科院分区：
文献类型：
--
作者：
Van Leeuwen, Thomas;Demaeght, Peter;Clark, Richard M.
由于甲壳素对节肢动物外骨骼的重要性，甲壳素的生物合成是害虫防治的一个有吸引力的靶标。这一点由经济上重要的苯甲酰脲化合物证明，这些化合物被广泛用作高度特异的杀虫剂来控制昆虫种群。然而，抑制甲壳素生物生成的化合物的目标位置仍然难以捉摸，这可能阻碍了害虫管理中潜在作用模式的充分利用。在这里，我们展示了杀螨剂依曲唑抑制二斑叶螨(Tetranychus Urticae)几丁质的生物合成，二斑蜘蛛是一种重要的经济害虫。然后，我们开发了一种基于高通量基因组测序的群体水平批量分离作图方法，以在野外收集的群体中识别单基因、隐性抗乙恶唑的基因座。在其他遗传学研究的支持下，包括对多个耐药株的测序和基因互补测试，我们将主要的麻风菌几丁质合成酶(CHS1)的非同义突变与耐药性联系在一起。这种变化发生在CHS1的C端跨膜结构域，位于一个高度保守的区域，可能起到非催化但必不可少的功能。我们在CHS1中发现的靶点抗性突变表明，至少有一种高度特异的甲壳素生物合成抑制剂直接作用于抑制甲壳素合成酶。我们的工作也提出了其他甲壳素生物发生抑制剂，如苯甲酰脲化合物，也可能通过抑制甲壳素合成酶发挥作用的可能性。更广泛地说，我们的基因作图方法对于节肢动物的简单特征(抗性或其他)的高分辨率作图应该是强大的。
Because of its importance to the arthropod exoskeleton, chitin biogenesis is an attractive target for pest control. This point is demonstrated by the economically important benzoylurea compounds that are in wide use as highly specific agents to control insect populations. Nevertheless, the target sites of compounds that inhibit chitin biogenesis have remained elusive, likely preventing the full exploitation of the underlying mode of action in pest management. Here, we show that the acaricide etoxazole inhibits chitin biogenesis in Tetranychus urticae (the two-spotted spider mite), an economically important pest. We then developed a population-level bulk segregant mapping method, based on high-throughput genome sequencing, to identify a locus for monogenic, recessive resistance to etoxazole in a field-collected population. As supported by additional genetic studies, including sequencing across multiple resistant strains and genetic complementation tests, we associated a nonsynonymous mutation in the major T. urticae chitin synthase (CHS1) with resistance. The change is in a C-terminal transmembrane domain of CHS1 in a highly conserved region that may serve a noncatalytic but essential function. Our finding of a target-site resistance mutation in CHS1 shows that at least one highly specific chitin biosynthesis inhibitor acts directly to inhibit chitin synthase. Our work also raises the possibility that other chitin biogenesis inhibitors, such as the benzoylurea compounds, may also act by inhibition of chitin synthases. More generally, our genetic mapping approach should be powerful for high-resolution mapping of simple traits (resistance or otherwise) in arthropods.