Miranda Jaclyn A, Culley Alexander I, Schvarcz Christopher R, Steward Grieg F
Department of Oceanography, Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, HI, 96822, USA.
Environ Microbiol. 2016 Nov;18(11):3714-3727. doi: 10.1111/1462-2920.13291. Epub 2016 Apr 28.
Early work on marine algal viruses focused exclusively on those having DNA genomes, but recent studies suggest that RNA viruses, especially those with positive-sense, single-stranded RNA (+ssRNA) genomes, are abundant in tropical and temperate coastal seawater. To test whether this was also true of polar waters, we estimated the relative abundances of RNA and DNA viruses using a mass ratio approach and conducted shotgun metagenomics on purified viral samples collected from a coastal site near Palmer Station, Antarctica on six occasions throughout a summer phytoplankton bloom (November-March). Our data suggest that RNA viruses contributed up to 65% of the total virioplankton (8-65%), and that, as observed previously in warmer waters, the majority of RNA viruses in these Antarctic RNA virus metagenomes had +ssRNA genomes most closely related to viruses in the order Picornavirales. Assembly of the metagenomic reads resulted in five novel, nearly complete genomes, three of which had features similar to diatom-infecting viruses. Our data are consistent with the hypothesis that RNA viruses influence diatom bloom dynamics in Antarctic waters.
早期对海洋藻类病毒的研究仅聚焦于那些具有DNA基因组的病毒，但最近的研究表明，RNA病毒，尤其是那些具有正链、单链RNA（+ssRNA）基因组的病毒，在热带和温带沿海水域中大量存在。为了测试极地水域是否也是如此，我们使用质量比方法估算了RNA病毒和DNA病毒的相对丰度，并在整个夏季浮游植物大量繁殖期间（11月至3月），六次从南极帕尔默站附近的一个沿海地点采集纯化的病毒样本，进行鸟枪法宏基因组学分析。我们的数据表明，RNA病毒在总病毒浮游生物中所占比例高达65%（8%-65%），并且，正如之前在温暖水域中观察到的那样，这些南极RNA病毒宏基因组中的大多数RNA病毒具有与微小核糖核酸病毒目病毒最密切相关的+ssRNA基因组。宏基因组读数的组装产生了五个新的、近乎完整的基因组。其中三个基因组具有与感染硅藻的病毒相似的特征。我们的数据与RNA病毒影响南极水域硅藻大量繁殖动态这一假设一致。
