School of Biological Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.
Queensland Department of Agriculture and Fisheries, Queensland Government, Dutton Park, Queensland 4012, Australia.
Genetics. 2018 May;209(1):281-290. doi: 10.1534/genetics.118.300688. Epub 2018 Mar 1.
Next-generation sequencing methods enable identification of the genetic basis of traits in species that have no prior genomic information available. The combination of next-generation sequencing, variant analysis, and linkage is a powerful way of identifying candidate genes for a trait of interest. Here, we used a comparative transcriptomics [RNA sequencing (RNAseq)] and genetic linkage analysis approach to identify the gene. variants are responsible for resistance to the fumigant phosphine (PH) that is used to control insect pests of stored grain. In each of the four major species of pest insect of grain we have investigated, there are two major resistance genes, and , which interact synergistically to produce strongly phosphine-resistant insects. Using RNAseq and genetic linkage analyses, we identified candidate resistance () genes in phosphine-resistant strains of three species: (129 candidates), (206 candidates), and (645 candidates). We then compared these candidate genes to 17 candidate resistance genes previously mapped in and found only one orthologous gene, a (C), to be associated with the locus in all four species. This gene had either missense amino acid substitutions and/or insertion/deletions/frameshift variants in each of 18 phosphine-resistant strains that were not observed in the susceptible strains of the four species. We propose a model of phosphine action and resistance in which phosphine induces lipid peroxidation through reactive oxygen species generated by dihydrolipoamide dehydrogenase, whereas disruption of in resistant insects decreases the polyunsaturated fatty acid content of membranes, thereby limiting the potential for lipid peroxidation.
下一代测序方法使我们能够识别具有先前基因组信息的物种的特征的遗传基础。下一代测序、变异分析和连锁的结合是识别感兴趣的特征的候选基因的强大方法。在这里，我们使用比较转录组学 [RNA 测序 (RNAseq)] 和遗传连锁分析方法来鉴定基因。变体负责抵抗用于控制储存谷物害虫的熏蒸剂磷化氢 (PH)。在我们研究的四种主要谷物害虫中，有两个主要的抗性基因和，它们协同作用产生对磷化氢具有强烈抗性的昆虫。使用 RNAseq 和遗传连锁分析，我们在三种物种的磷化氢抗性株中鉴定出候选抗性 () 基因：(129 个候选基因)、(206 个候选基因)和 (645 个候选基因)。然后，我们将这些候选基因与先前在 中映射的 17 个候选抗性基因进行比较，发现只有一个同源基因，一个 (C)，与四个物种中的 位点相关。在 18 个磷化氢抗性株中，该基因在每个基因中都有错义氨基酸取代和/或插入/缺失/移码变异，而在四个物种的敏感株中则没有观察到这些变异。我们提出了一个磷化氢作用和抗性的模型，其中磷化氢通过二氢硫辛酸脱氢酶产生的活性氧诱导脂质过氧化，而抗性昆虫中 的破坏降低了膜中多不饱和脂肪酸的含量，从而限制了脂质过氧化的潜力。
