Paleoviral maintenance in a Holarctic Daphnia species complex, 2010-2012

Daphniids are critical members of Holarctic freshwater ecosystems. However, little is known of their interactions with RNA viruses. These data represent sequence information supporting the hypothesis that a viral gene from a Phelobvirus-like RNA virus has been transferred into the genomes of common species of Arctic Daphnia. The gene is similar to the RNA-Dependent RNA polymerase (RDRP) gene of phleboviruses (Phenuiviridae). The data also contain mitochondrial sequence from the host to classify the lineage of Daphnia that contains each "fossil" virus. These data indicate, for the first time, that common species of Daphnia in the Arctic have been infected with RNA viruses. Moreover, the evidence indicates that viral genes may be maintained for a presently unknown host function. Because the paleoviruses represent a "captured" viral gene (RDRP) that is often used for the classification of RNA viruses, these data also provide a means of identifying and studying novel viruses and their present interactions in Arctic freshwater.

溞科（Daphniidae）物种是全北界淡水生态系统中的关键类群。然而，目前学界对其与RNA病毒（RNA virus）的相互作用仍知之甚少。本数据集所包含的序列信息，支持如下假说：一类类似Phelob病毒的RNA病毒所携带的病毒基因，已发生水平转移并整合至北极常见溞属（Daphnia）物种的基因组中。该基因与白蛉病毒科（Phenuiviridae）白蛉病毒属（Phlebovirus）的RNA依赖RNA聚合酶（RNA-Dependent RNA Polymerase, RDRP）基因具有序列同源性。本数据集同时包含宿主的线粒体序列，用于对携带该“古病毒”序列的溞属类群进行谱系分类。本数据首次证实，北极地区的常见溞属物种曾感染RNA病毒。此外，相关证据表明，该病毒基因可能因尚未明确的宿主功能而得以长期保留。鉴于这类古病毒代表了一类常被用于RNA病毒分类的“捕获”病毒基因（即RDRP基因），本数据集同时为识别、研究新型RNA病毒及其在北极淡水生态系统中的当前互作关系提供了有效手段。