Phylogenomics reveals the origin of mammal lice out of Afrotheria
Phylogenomics reveals the origin of mammal lice out of Afrotheria
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DOI：
10.1038/s41559-022-01803-1
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发表时间：
2022-07
影响因子：
16.8
通讯作者：
K. Johnson;C. Matthee;Jorge Doña
中科院分区：
文献类型：
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作者：
K. Johnson;C. Matthee;Jorge Doña
哺乳动物寄生着多种多样的寄生虫。虱，包括超过5，000种，是一组体外寄生虫，其主要谱系在主要哺乳动物群体中具有某种拼凑的分布。在这里，我们通过重建这些虱子的更高水平的同源性来探索哺乳动物虱子多样化的模式，利用全基因组序列读取来组装整个基因组的单拷贝直系同源基因。虱子的进化树表明，胎盘哺乳动物虱子的三个主要谱系有一个共同的祖先。通过与哺乳动物宿主的生殖发育比较，发现这群虱子的祖先是大象、象鼩和蹄兔的共同祖先（即非洲兽）。其他有胎盘哺乳动物群体通过从这些非洲兽的祖先身上转换宿主来获得虱子。此外，所有寄生虱的祖先宿主群（鸟类与哺乳动物）的重建支持鸟类祖先宿主，表明非洲兽的祖先通过从古老的鸟类宿主转换获得这些寄生虫。这些结果揭示了长期存在的问题，为什么寄生虱的主要群体在哺乳动物中分布不均匀，并揭示了哺乳动物虱的起源。
Mammals host a wide diversity of parasites. Lice, comprising more than 5,000 species, are one group of ectoparasites whose major lineages have a somewhat patchwork distribution across the major groups of mammals. Here we explored patterns in the diversification of mammalian lice by reconstructing a higher-level phylogeny of these lice, leveraging whole genome sequence reads to assemble single-copy orthologue genes across the genome. The evolutionary tree of lice indicated that three of the major lineages of placental mammal lice had a single common ancestor. Comparisons of this parasite phylogeny with that for their mammalian hosts indicated that the common ancestor of elephants, elephant shrews and hyraxes (that is, Afrotheria) was the ancestral host of this group of lice. Other groups of placental mammals obtained their lice via host-switching out of these Afrotherian ancestors. In addition, reconstructions of the ancestral host group (bird versus mammal) for all parasitic lice supported an avian ancestral host, indicating that the ancestor of Afrotheria acquired these parasites via host-switching from an ancient avian host. These results shed new light on the long-standing question of why the major groups of parasitic lice are not uniformly distributed across mammals and reveal the origins of mammalian lice.