Genomes of trombidid mites reveal novel predicted allergens and laterally transferred genes associated with secondary metabolism
Genomes of trombidid mites reveal novel predicted allergens and laterally transferred genes associated with secondary metabolism
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DOI：
10.1093/gigascience/giy127
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发表时间：
2018-11-15
期刊：
影响因子：
9.2
通讯作者：
Makepeace, Benjamin L.
中科院分区：
文献类型：
--
作者：
Dong, Xiaofeng;Chaisiri, Kittipong;Makepeace, Benjamin L.
背景： Trombidid 螨具有独特的生命周期，其中只有幼虫阶段是外寄生的。在恙螨总科（“恙螨”）中，幼虫优先以脊椎动物为食，包括人类。纤颤菌属的物种是一种潜在致命的细菌感染——丛林斑疹伤寒——的媒介，每年影响 100 万人。此外，恙螨还可引起人类和家养动物的瘙痒性皮炎（恙虫病）。在 Trombidioidea（绒螨）中，幼虫以其他节肢动物为食，是农业害虫的潜在生物防治剂。在这里，我们展示了第一个 trombidid 螨基因组，该基因组是从恙螨（Leptotrombidium deliense）和绒螨（Dinothrombiumtinctorium）获得的。结果：使用 Illumina 技术进行测序。使用单个成年样本，从两个双端文库和一个配偶对文库生成了 D.tinctorium 的 180 Mb 草稿组件。对于 L. deliense，使用具有单个双端文库的汇集的、饱满的幼虫获得了较低覆盖率的草案组装体 (117 Mb)。值得注意的是，这两个基因组都显示出古代来自土壤的细菌或真菌的横向基因转移的证据。转移的基因赋予动物罕见的功能，包括萜烯和类胡萝卜素的合成。在 L. deliense 基因组中预测了 37 个过敏蛋白家族，其中 9 个是独特的。初步蛋白质组学分析确定了幼虫中的几种假定过敏原。结论：长螨的基因组似乎比其他螨类的基因组更具动态性。未来研究的首要任务是确定该分类单元中萜烯合成的生物学功能及其在疾病控制中的开发潜力。
Background: Trombidid mites have a unique life cycle in which only the larval stage is ectoparasitic. In the superfamily Trombiculoidea ("chiggers"), the larvae feed preferentially on vertebrates, including humans. Species in the genus Leptotrombidium are vectors of a potentially fatal bacterial infection, scrub typhus, that affects 1 million people annually. Moreover, chiggers can cause pruritic dermatitis (trombiculiasis) in humans and domesticated animals. In the Trombidioidea (velvet mites), the larvae feed on other arthropods and are potential biological control agents for agricultural pests. Here, we present the first trombidid mites genomes, obtained both for a chigger, Leptotrombidium deliense, and for a velvet mite, Dinothrombium tinctorium. Results: Sequencing was performed using Illumina technology. A 180 Mb draft assembly for D. tinctorium was generated from two paired-end and one mate-pair library using a single adult specimen. For L. deliense, a lower-coverage draft assembly (117 Mb) was obtained using pooled, engorged larvae with a single paired-end library. Remarkably, both genomes exhibited evidence of ancient lateral gene transfer from soil-derived bacteria or fungi. The transferred genes confer functions that are rare in animals, including terpene and carotenoid synthesis. Thirty-seven allergenic protein families were predicted in the L. deliense genome, of which nine were unique. Preliminary proteomic analyses identified several of these putative allergens in larvae. Conclusions: Trombidid mite genomes appear to be more dynamic than those of other acariform mites. A priority for future research is to determine the biological function of terpene synthesis in this taxon and its potential for exploitation in disease control.