Although viruses comprise the most abundant genetic material in the biosphere, to date only several thousand virus species have been formally defined. Such a limited perspective on virus diversity has in part arisen because viruses were traditionally considered only as etiologic agents of overt disease in humans or economically important species and were often difficult to identify using cell culture. This view has dramatically changed with the rise of metagenomics, which is transforming virus discovery and revealing a remarkable diversity of viruses sampled from diverse cellular organisms. These newly discovered viruses help fill major gaps in the evolutionary history of viruses, revealing a near continuum of diversity among genera, families, and even orders of RNA viruses. Herein, we review some of the recent advances in our understanding of the RNA virosphere that have stemmed from metagenomics, note future directions, and highlight some of the remaining challenges to this rapidly developing field.

中文翻译：

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通过无偏元基因组学扩展RNA Virosphere。

尽管病毒是生物圈中最丰富的遗传物质，但迄今为止，仅正式定义了数千种病毒。出现这种对病毒多样性的有限观点的部分原因是，传统上仅将病毒视为人类或经济上重要物种的明显疾病的病原体，并且通常难以使​​用细胞培养法进行鉴定。随着宏基因组学的兴起，这种观点发生了巨大变化，宏基因组学正在改变病毒的发现，并揭示了从多种细胞有机体中采样的大量病毒。这些新发现的病毒帮助填补了病毒进化史上的重大空白，揭示了RNA病毒的属，科甚至顺序之间几乎是连续的。在此处，