Angly Florent E, Felts Ben, Breitbart Mya, Salamon Peter, Edwards Robert A, Carlson Craig, Chan Amy M, Haynes Matthew, Kelley Scott, Liu Hong, Mahaffy Joseph M, Mueller Jennifer E, Nulton Jim, Olson Robert, Parsons Rachel, Rayhawk Steve, Suttle Curtis A, Rohwer Forest
Department of Biology, San Diego State University, San Diego, California, USA.
PLoS Biol. 2006 Nov;4(11):e368. doi: 10.1371/journal.pbio.0040368.
Viruses are the most common biological entities in the marine environment. There has not been a global survey of these viruses, and consequently, it is not known what types of viruses are in Earth's oceans or how they are distributed. Metagenomic analyses of 184 viral assemblages collected over a decade and representing 68 sites in four major oceanic regions showed that most of the viral sequences were not similar to those in the current databases. There was a distinct "marine-ness" quality to the viral assemblages. Global diversity was very high, presumably several hundred thousand of species, and regional richness varied on a North-South latitudinal gradient. The marine regions had different assemblages of viruses. Cyanophages and a newly discovered clade of single-stranded DNA phages dominated the Sargasso Sea sample, whereas prophage-like sequences were most common in the Arctic. However most viral species were found to be widespread. With a majority of shared species between oceanic regions, most of the differences between viral assemblages seemed to be explained by variation in the occurrence of the most common viral species and not by exclusion of different viral genomes. These results support the idea that viruses are widely dispersed and that local environmental conditions enrich for certain viral types through selective pressure.
病毒是海洋环境中最常见的生物实体。目前尚未对这些病毒进行全球范围的调查，因此，尚不清楚地球海洋中存在哪些类型的病毒以及它们是如何分布的。对在十年间收集的、代表四个主要海洋区域68个地点的184个病毒群落进行的宏基因组分析表明，大多数病毒序列与当前数据库中的序列不相似。病毒群落具有明显的“海洋特性”。全球多样性非常高，据推测有几十万种，区域丰富度随南北纬度梯度而变化。不同海洋区域的病毒群落不同。噬蓝藻病毒和新发现的单链DNA噬菌体分支在马尾藻海样本中占主导地位，而前噬菌体样序列在北极最为常见。然而，大多数病毒物种被发现分布广泛。由于海洋区域之间存在大多数共享物种，病毒群落之间的大多数差异似乎可以通过最常见病毒物种出现频率的变化来解释，而不是通过不同病毒基因组的排除来解释。这些结果支持了病毒广泛传播的观点，以及当地环境条件通过选择压力富集某些病毒类型的观点。
