Viral activities and life cycles in deep subseafloor sediments
Viral activities and life cycles in deep subseafloor sediments
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DOI：
10.1111/1758-2229.12316
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发表时间：
2015-12-01
影响因子：
3.3
通讯作者：
Jorgensen, Bo Barker
中科院分区：
文献类型：
--
作者：
Engelhardt, Tim;Orsi, William D.;Jorgensen, Bo Barker
病毒在海洋地下沉积物中非常丰富，甚至可以超过原核生物的数量。然而，它们对微生物种群的活性和定量影响仍然知之甚少。在这里，我们使用基因表达数据从出版的大陆边缘subseafloor元转录组定性评估病毒的多样性和活性在沉积物中，海底（mbsf）下159米。元转录组数据的挖掘揭示了4651个代表性的病毒同源物（RVH），占所有元转录组序列读段的2.2%，其与病毒蛋白具有密切的翻译同源性（平均77%，范围60-97%氨基酸同一性）。在30 mbsf的上层中仅检测到感染RVH的铜绿假单胞菌，而丝状丝状丝膜病毒的RVH在最深的沉积层中占主导地位。RVH指示溶源性噬菌体-宿主相互作用和裂解活性，特别是细胞裂解，检测到在所有分析的深度，并建议在这里研究的海洋深层生物圈的动态病毒-宿主协会。正在进行的裂解病毒活性进一步表明，表达成簇的，有规律的间隔，短回文重复相关的级联基因参与细胞防御病毒攻击。这些数据表明，病毒在秘鲁边缘的地下沉积物中的活动，并表明病毒确实会导致细胞死亡，并可能在海底下微生物生物量的周转中发挥重要作用。
Viruses are highly abundant in marine subsurface sediments and can even exceed the number of prokaryotes. However, their activity and quantitative impact on microbial populations are still poorly understood. Here, we use gene expression data from published continental margin subseafloor metatranscriptomes to qualitatively assess viral diversity and activity in sediments up to 159 metres below seafloor (mbsf). Mining of the metatranscriptomic data revealed 4651 representative viral homologues (RVHs), representing 2.2% of all metatranscriptome sequence reads, which have close translated homology (average 77%, range 60-97% amino acid identity) to viral proteins. Archaea-infecting RVHs are exclusively detected in the upper 30 mbsf, whereas RVHs for filamentous inoviruses predominate in the deepest sediment layers. RVHs indicative of lysogenic phage-host interactions and lytic activity, notably cell lysis, are detected at all analysed depths and suggest a dynamic virus-host association in the marine deep biosphere studied here. Ongoing lytic viral activity is further indicated by the expression of clustered, regularly interspaced, short palindromic repeat-associated cascade genes involved in cellular defence against viral attacks. The data indicate the activity of viruses in subsurface sediment of the Peruvian margin and suggest that viruses indeed cause cell mortality and may play an important role in the turnover of subseafloor microbial biomass.