Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle
Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle
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DOI：
10.1073/pnas.1003379107
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发表时间：
2010-07-06
影响因子：
11.1
通讯作者：
Pittendrigh, Barry R.
中科院分区：
文献类型：
--
作者：
Kirkness, Ewen F.;Haas, Brian J.;Pittendrigh, Barry R.
体虱（Pediculus humanus humanus）作为人类的强制性寄生虫，是流行性斑疹伤寒、回归热、战壕热等人类疾病的重要传播媒介。在这里，我们展示了体虱及其主要细菌内共生体 Candidatus Riesia pediculicola 的基因组序列。体虱拥有已知最小的昆虫基因组，大小为 108 Mb。尽管它是一种专性寄生虫，但它保留了非常完整的昆虫基础库，包括 10,773 个蛋白质编码基因和 57 个 microRNA。体虱基因组作为半变态昆虫的代表，为全变态昆虫的研究提供了参考。与其他昆虫基因组相比，体虱基因组中与环境感知和响应相关的基因明显较少，包括气味和味觉受体以及解毒酶。体虱 18 条小环线粒体染色体的独特结构可能与编码线粒体单链 DNA 结合蛋白的基因的丢失有关。强制性虱子内共生体 Candidatus Riesia pediculicola 的基因组在短的线性染色体和环状质粒上编码不到 600 个基因。该质粒含有合成泛酸所需的独特基因排列，泛酸是虱子饮食中缺乏的一种必需维生素。与自由生活的近亲相比，人体虱子、其主要内共生体及其所携带的细菌病原体的基因组都较小。因此，体虱基因组计划提供了独特的信息和工具，可用于增进对载体、共生体和病原体之间共同进化的理解。
As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens.