100-My history of bornavirus infections hidden in vertebrate genomes
100-My history of bornavirus infections hidden in vertebrate genomes
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DOI：
10.1073/pnas.2026235118
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发表时间：
2021-05-18
影响因子：
11.1
通讯作者：
Horie, Masayuki
中科院分区：
文献类型：
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作者：
Kawasaki, Junna;Kojima, Shohei;Horie, Masayuki
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)是一种古老的博纳病毒序列，来源于病毒信使RNA，这些信使RNA被逆转录并插入到动物基因组中，最有可能的是通过反转录转座子。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100例博尔纳病毒感染的历史。我们证实，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纳病毒谱系。灵长类动物基因组中的EBL根据其整合年龄形成分支，这表明感染灵长类祖先的博尔纳病毒谱系已经按时间顺序发生了变化。然而，一些博尔纳病毒谱系可能与灵长类祖先共存，并经历了数千万年的反复内化。此外，与灵长类祖先共存的博尔纳病毒血统也内源性地存在于一些祖先蝙蝠的基因组中。据报道，这些蝙蝠祖先的栖息地与灵长类祖先的迁徙路线重叠。这些结果表明，随着灵长类动物的迁徙，病毒与宿主的长期共存扩大了博尔纳病毒谱系的地理分布，并可能将它们的感染传播到这些蝙蝠祖先。我们的发现提供了对博尔纳病毒感染历史的洞察，这是仅使用现有病毒的研究无法推断的地质时间尺度，从而拓宽了我们对病毒-宿主共同进化的视角。
Although viruses have threatened our ancestors for millions of years, prehistoric epidemics of viruses are largely unknown. Endogenous bornavirus-like elements (EBLs) are ancient bornavirus sequences derived from the viral messenger RNAs that were reverse transcribed and inserted into animal genomes, most likely by retrotransposons. 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 My. We confirmed that ancient bornaviral infections have occurred in diverse vertebrate lineages, especially in primate ancestors. Phylogenetic analyses indicated that primate ancestors were infected with various bornaviral lineages during evolution. EBLs in primate genomes formed clades according to their integration ages, suggesting that bornavirus lineages infected with primate ancestors had changed chronologically. However, some bornaviral lineages may have coexisted with primate ancestors and underwent repeated endogenizations for tens of millions of years. Moreover, a bornaviral lineage that coexisted with primate ancestors also endogenized in the genomes of some ancestral bats. The habitats of these bat ancestors have been reported to overlap with the migration route of primate ancestors. These results suggest that longterm virus-host coexistence expanded the geographic distributions of the bornaviral lineage along with primate migration and may have spread their infections to these bat ancestors. Our findings provide insight into the history of bornavirus infections over geological timescales that cannot be deduced from research using extant viruses alone, thus broadening our perspective on virus-host coevolution.