Genomic viral integrations, termed endogenous viral elements (EVEs), are fragments of viruses in host chromosomes that provide information about viral evolution and could even help protect the host from infection. In the present study we examined EVEs in thirteen different Australian marsupial species to identify trends in their integration, commonality and to investigate their possible cellular function. We found that marsupial EVEs are commonly derived from viruses of the Bornaviridae, Filoviridae and Parvoviridae families, and circulated up to 160 million years ago. We also show the EVEs are actively transcribed into both long and short RNA molecules in marsupials, and propose they are involved in a cellular defence mechanism to protect the germline from viral genomic invasion.

基因组病毒整合，称为内源性病毒元件 (EVE)，是宿主染色体中的病毒片段，提供有关病毒进化的信息，甚至可以帮助保护宿主免受感染。在本研究中，我们检查了 13 种不同的澳大利亚有袋动物物种的 EVE，以确定它们的整合趋势、共性，并研究它们可能的细胞功能。我们发现有袋动物的EVEs通常来源于博纳病毒科、丝状病毒科和细小病毒科的病毒，并在1.6亿年前循环。我们还表明，在有袋动物中，EVE 被主动转录成长 RNA 和短 RNA 分子，并提出它们参与细胞防御机制，以保护生殖细胞免受病毒基因组入侵。