One hundred million years history of bornavirus infections hidden in vertebrate genomes
One hundred million years history of bornavirus infections hidden in vertebrate genomes
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DOI：
10.1101/2020.12.02.408005
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发表时间：
2020-12
期刊：
影响因子：
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通讯作者：
Junna Kawasaki;Shohei Kojima;Yahiro Mukai;K. Tomonaga;Masayuki Horie
中科院分区：
文献类型：
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作者：
Junna Kawasaki;Shohei Kojima;Yahiro Mukai;K. Tomonaga;Masayuki Horie
尽管病毒已经威胁我们的祖先数百万年了，但史前病毒的流行在很大程度上是未知的。内源性博纳病毒样元件(EBL)是一种古老的病毒序列，已整合到动物基因组中。这些元素可以作为分子化石记录来追踪过去的博尔纳病毒感染。在这项研究中，我们系统地鉴定了脊椎动物基因组中的EBL，并揭示了近1亿年来博尔纳病毒的感染历史。我们发现，古老的博纳病毒感染发生在不同的脊椎动物谱系中，特别是在灵长类祖先中。系统发育分析表明，灵长类动物的祖先在进化过程中感染了不同的博尔纳病毒谱系。此外，灵长类基因组中的EBL根据整合年龄形成了分支，这表明博尔纳病毒的流行谱系已经按时间顺序发生了变化。然而，我们发现一些博尔纳病毒谱系与灵长类祖先共存，并经历了数千万年的反复内源性。此外，这种与灵长类祖先共存的病毒谱系在一些祖先蝙蝠中也被内源性。值得注意的是，据报道，这些蝙蝠祖先的地理分布与灵长类祖先的迁徙路线重叠，这表明长期的病毒与宿主共存可能扩大了病毒谱系的地理分布，并可能将它们的感染传播到新的宿主。因此，我们的发现描述了隐藏的病毒和宿主在地质时间尺度上的共同进化史，包括流行的博尔纳病毒谱系的时间变化，病毒和宿主的长期共存，以及病毒感染的扩大。
Although viruses have threatened our ancestors for millions of years, prehistoric epidemics of viruses are largely unknown. Endogenous bornavirus-like elements (EBLs) are ancient viral sequences that have been integrated into animal genomes. These elements can be used as molecular fossil records to trace past bornaviral infections. In this study, we systematically identified EBLs in vertebrate genomes and revealed the history of bornavirus infections over nearly 100 million years. We found that ancient bornaviral infections have occurred in diverse vertebrate lineages, especially in primate ancestors. Phylogenetic analyses indicated that primate ancestors had been infected with various bornaviral lineages during evolution. Moreover, EBLs in primate genomes formed clades according to their integration ages, suggesting that epidemic lineages of bornaviruses had changed chronologically. However, we found that some bornaviral lineages coexisted with primate ancestors and underwent repeated endogenizations for tens of millions of years. Furthermore, this viral lineage that coexisted with primate ancestors was also endogenized in some ancestral bats. Notably, the geographic distributions of these bat ancestors have been reported to overlap with the migration route of primate ancestors, suggesting that long-term virus-host coexistence could have expanded the geographic distributions of the viral lineage and might have spread their infections to new hosts. Thus, our findings describe hidden virus-host co-evolutionary history over geological timescales, including chronological change in epidemic bornaviral lineages, long-term virus-host coexistence, and expansion of viral infections.