Tee Hwee Sze, Ku Chuan
Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
Mol Biol Evol. 2025 Feb 3;42(2). doi: 10.1093/molbev/msaf033.
Viruses are widespread parasites with important impacts on public health, economy, and ecosystems. However, little is known about their origins, ages, and early evolutionary relationships with hosts. Here, we infer the maximum divergence times for eukaryotic giant DNA viruses (phylum Nucleocytoviricota) with dating analyses calibrated by host taxon ages of virus lineages with specific host ranges. The last common ancestor of Nucleocytoviricota existed after 1,000 million years ago, suggesting a much later origin than that of the eukaryotes. The early evolution of Nucleocytoviricota either coincided with or postdated a substantial increase in the oxygen levels on the Earth's surface during the Neoproterozoic Era. The lineage diversification of giant viruses was frequently associated with host shifts, including two major transitions from amoebozoan hosts to animal hosts that eventually led to the emergence of iridoviruses and African swine fever viruses within the last 450 million years. These results outline the evolutionary timescale of a major virus group and are pivotal for further understanding the virus-host interactions and their potential ecological roles in the Earth's history.
病毒是广泛存在的寄生虫，对公共卫生、经济和生态系统都有重要影响。然而，关于它们的起源、年代以及与宿主的早期进化关系，我们却知之甚少。在此，我们通过对具有特定宿主范围的病毒谱系的宿主分类群年龄进行校准的定年分析，推断真核生物巨型DNA病毒（核质巨DNA病毒门）的最大分歧时间。核质巨DNA病毒门的最后一个共同祖先存在于10亿年前之后，这表明其起源比真核生物晚得多。核质巨DNA病毒门的早期进化要么与新元古代地球表面氧气水平的大幅增加同时发生，要么在其之后。巨型病毒的谱系多样化常常与宿主转移相关，包括在过去4.5亿年内从变形虫宿主到动物宿主的两次重大转变，最终导致了虹彩病毒和非洲猪瘟病毒的出现。这些结果勾勒出了一个主要病毒类群的进化时间尺度，对于进一步理解病毒 - 宿主相互作用及其在地球历史中潜在的生态作用至关重要。
