Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses
Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses
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DOI：
10.1038/ismej.2013.67
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发表时间：
2013-09-01
期刊：
影响因子：
11
通讯作者：
Sullivan, Matthew B.
中科院分区：
文献类型：
--
作者：
Brum, Jennifer R.;Schenck, Ryan O.;Sullivan, Matthew B.
病毒通过引起微生物死亡、通过裂解和辅助代谢基因表达改变营养物和有机物通量以及通过水平基因转移改变微生物进化轨迹来影响海洋生态系统。有限的宿主范围和不同类型病毒的遗传潜力意味着调查海洋中存在的病毒类型及其在世界海洋中的空间分布对于了解海洋病毒的全球影响至关重要。在这里，我们评估病毒的形态特征（形态型，衣壳直径和尾长），使用定量透射电子显微镜（qTEM）的方法在世界上的海洋和海洋采样通过塔拉海洋探险。对qTEM方法的广泛实验验证表明，样品保存和制备均不会显著改变天然病毒形态学特征。全球取样分析表明，形态特征并不随深度（表层与深层叶绿素最大值沃茨）或海洋区域而一致变化。相反，温度，盐度和氧浓度，但不是叶绿素a浓度，更解释在病毒组合形态特征的差异进行评估。令人惊讶的是，考虑到大多数培养的细菌病毒都是有尾的，无尾病毒似乎在数量上占主导地位，因为它们占观察到的病毒颗粒的51-92%。总之，这些结果记录了全球海洋病毒的形态特征，表明它们的最小变异性更多地是由环境条件而不是地理条件来解释的，并表明无尾病毒可能是未来研究中最重要的生态目标。
Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51-92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research.