The longhorned beetles, Rhaphuma horsfieldi and Xylotrechus quadripes, are two polyphagous insects with larvae feeding on different host plants. In this study, we identified and characterized three gene superfamilies of cytochrome P450s (CYPs), carboxylesterases (COEs) and glutathione-S-transferases (GSTs) involved in the detoxification of endobiotics (e.g., hormones and steroids) and xenobiotics (e.g., insecticides, sex pheromones and plant allelochemicals) through a combination approach of bioinformatics, phylogenetics, expression profiles and genomics. Transcriptome analyses led to the identification of 281 transcripts encoding 135 P450s, 108 COEs and 38 GSTs from the two beetles, coupled with comparative studies of detoxification genes among coleopteran species, suggesting a correlation between host range and the sizes of P450 or COE gene repertoires. The P450s of two beetles were phylogenetically classified into four clades, representing the majority of genes in the CYP3 clan. The COEs from R. horsfieldi and X. quadripes were separately grouped into 11 and 10 clades, and the GST superfamily was assigned into six clades. Expression profiles revealed that the detoxification genes were broadly expressed in various tissues as an implication of functional diversities. Ultimately and more importantly, five alternative splicing events in the Epsilon GSTs, including RhorGSTe7.1/GSTe7.2 and XquaGSTe3.1/GST3.2, were acquired in Coleoptera, in which these genes and their orthologs shared highly conserved gene structure. Our current study has complemented the resources for the detoxification genes in the family Cerambycidae, and allows for functional experiments to identify candidate molecular targets involved in pest resistance to insecticides like organophosphates, organochlorines and pyrethroids.

中文翻译：

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鉴定和鉴定了两种陶拉比甲虫（Rhaphuma horsfieldi）和Xylotrechus quadripes（鞘翅目：Cerambycidae：Clytini）的解毒基因。

长角甲虫Rhaphuma horsfieldi和Xylotrechus quadripes是两种多食性昆虫，幼虫以不同的寄主植物为食。在这项研究中，我们确定并表征了参与内毒素（例如激素和类固醇）和异源生物（例如杀虫剂）排毒的细胞色素P450（CYP），羧酸酯酶（COE）和谷胱甘肽S-转移酶（GST）的三个基因超家族。 ，性信息素和植物化感物质）通过生物信息学，系统发育，表达谱和基因组学的组合方法。通过转录组分析，鉴定了来自两个甲虫的281个编码135个P450、108个COE和38个GST的转录本，并进行了鞘翅目物种中解毒基因的比较研究，提示宿主范围与P450或COE基因库大小之间存在相关性。将两个甲虫的P450进行系统发育分析，分为四个进化枝，代表CYP3家族中的大多数基因。R. horsfieldi和X. quadripes的COE分别分为11和10个进化枝，GST超家族被划分为6个进化枝。表达谱表明，解毒基因在多种组织中广泛表达，暗示着功能多样性。最终，更重要的是，在鞘翅目中获得了Epsilon GST中的五个选择性剪​​接事件，包括RhorGSTe7.1 / GSTe7.2和XquaGSTe3.1 / GST3.2，其中这些基因及其直系同源基因共享高度保守的基因结构。