Analysis of virus genomes from glacial environments reveals novel virus groups with unusual host interactions.
Analysis of virus genomes from glacial environments reveals novel virus groups with unusual host interactions.
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DOI：
10.3389/fmicb.2015.00656
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发表时间：
2015
影响因子：
5.2
通讯作者：
Barker G
中科院分区：
文献类型：
--
作者：
Bellas CM;Anesio AM;Barker G
冰川生态系统中的微生物群落多样、活跃，并受到强大的病毒压力和感染率的影响。在这项研究中，我们分析了来自斯瓦尔巴群岛和格陵兰冰盖冰洞生态系统的三个dsDNA病毒组组装的假定病毒基因组，以评估病毒在这些栖息地中的潜在宿主和功能作用。我们从病毒大小的片段中收集了2.08亿个片段，并开发了一种从细胞污染中选择真正病毒支架的程序。我们整理的病毒文库包含546个长度为230 Kb的支架，其中54个为环状病毒共识基因组。对病毒标记基因的分析显示，已经组装了各种各样的病毒，包括噬菌体、噬藻体、核胞质大DNA病毒和噬菌体，假定的宿主被确定为蓝藻门、阿尔法变形菌门、γ变形菌门、放线菌门、厚壁菌门、真核藻类和变形虫。全基因组比较发现，大多数环状基因组支架（CGS）形成了12个新的类群，其中两个类群含有多个具有质粒样特性的噬菌体成员，包括一组具有质粒样分割基因和毒素-抗毒素依赖模块以确保其复制的噬菌体-质粒组和一组卫星噬菌体-质粒组。令人惊讶的是，我们还组装了一个噬菌体，该噬菌体不仅编码质粒分割基因，而且编码有规则间隔的短回文重复(CRISPR)/Cas适应性细菌免疫系统。其中一个间隔物与我们的病毒体内的另一个噬菌体完全匹配，这表明在该系统的一种新用途中，溶原可能能够赋予其细菌宿主对其他噬菌体的免疫力。总之，这些结果表明，在冰川环境中存在高度新颖和多样化的病毒群，其中一些病毒利用非常不寻常的生命策略和基因来控制它们的复制并与宿主保持长期关系。
Microbial communities in glacial ecosystems are diverse, active, and subjected to strong viral pressures and infection rates. In this study we analyse putative virus genomes assembled from three dsDNA viromes from cryoconite hole ecosystems of Svalbard and the Greenland Ice Sheet to assess the potential hosts and functional role viruses play in these habitats. We assembled 208 million reads from the virus-size fraction and developed a procedure to select genuine virus scaffolds from cellular contamination. Our curated virus library contained 546 scaffolds up to 230 Kb in length, 54 of which were circular virus consensus genomes. Analysis of virus marker genes revealed a wide range of viruses had been assembled, including bacteriophages, cyanophages, nucleocytoplasmic large DNA viruses and a virophage, with putative hosts identified as Cyanobacteria, Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, Firmicutes, eukaryotic algae and amoebae. Whole genome comparisons revealed the majority of circular genome scaffolds (CGS) formed 12 novel groups, two of which contained multiple phage members with plasmid-like properties, including a group of phage-plasmids possessing plasmid-like partition genes and toxin-antitoxin addiction modules to ensure their replication and a satellite phage-plasmid group. Surprisingly we also assembled a phage that not only encoded plasmid partition genes, but a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas adaptive bacterial immune system. One of the spacers was an exact match for another phage in our virome, indicating that in a novel use of the system, the lysogen was potentially capable of conferring immunity on its bacterial host against other phage. Together these results suggest that highly novel and diverse groups of viruses are present in glacial environments, some of which utilize very unusual life strategies and genes to control their replication and maintain a long-term relationship with their hosts.
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影响因子：
3.7
作者：
Garcia-Heredia I;Martin-Cuadrado AB;Mojica FJ;Santos F;Mira A;Antón J;Rodriguez-Valera F
通讯作者：
Rodriguez-Valera F
影响因子：
4.4
作者：
Kim, Kyoung-Ho;Bae, Jin-Woo
通讯作者：
Bae, Jin-Woo
影响因子：
6.7
作者：
Edwards, Arwyn;Pachebat, Justin A.;Sattler, Birgit
通讯作者：
Sattler, Birgit
影响因子：
1.7
作者：
Cameron, Karen A.;Hodson, Andrew J.;Osborn, A. Mark
通讯作者：
Osborn, A. Mark
影响因子：
3.7
作者：
Hurwitz BL;Sullivan MB
通讯作者：
Sullivan MB