Weynberg Karen D, Laffy Patrick W, Wood-Charlson Elisha M, Turaev Dmitrij, Rattei Thomas, Webster Nicole S, van Oppen Madeleine J H
Australian Institute of Marine Science, Townsville, Queensland, Australia.
School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.
PeerJ. 2017 Nov 17;5:e4054. doi: 10.7717/peerj.4054. eCollection 2017.
Stony corals (Scleractinia) are marine invertebrates that form the foundation and framework upon which tropical reefs are built. The coral animal associates with a diverse microbiome comprised of dinoflagellate algae and other protists, bacteria, archaea, fungi and viruses. Using a metagenomics approach, we analysed the DNA and RNA viral assemblages of seven coral species from the central Great Barrier Reef (GBR), demonstrating that tailed bacteriophages of the dominate across all species examined, and ssDNA viruses, notably the , are also prevalent. Most sequences with matches to eukaryotic viruses were assigned to six viral families, including four Nucleocytoplasmic Large DNA Viruses (NCLDVs) families: , as well as and . Contrary to previous findings, were rare in these GBR corals. Sequences of a ssRNA virus with similarities to the dinornavirus, ssRNA virus of the that infects free-living dinoflagellates, were observed in three coral species. We also detected viruses previously undescribed from the coral holobiont, including a virus that targets fungi associated with the coral species . Functional analysis of the assembled contigs indicated a high prevalence of latency-associated genes in the coral-associated viral assemblages, several host-derived auxiliary metabolic genes (AMGs) for photosynthesis (, genes encoding the photosystem II D1 and D2 proteins respectively), as well as potential nematocyst toxins and antioxidants (genes encoding green fluorescent-like chromoprotein). This study expands the currently limited knowledge on coral-associated viruses by characterising viral composition and function across seven GBR coral species.
石珊瑚（造礁石珊瑚目）是构成热带珊瑚礁基础和框架的海洋无脊椎动物。珊瑚动物与由甲藻和其他原生生物、细菌、古菌、真菌及病毒组成的多样微生物群相关联。我们采用宏基因组学方法，分析了来自大堡礁中部的7种珊瑚的DNA和RNA病毒群落，结果表明，在所检测的所有珊瑚物种中，长尾噬菌体占主导地位，单链DNA病毒，尤其是圆环病毒也很普遍。大多数与真核病毒匹配的序列被归为6个病毒科，包括4个核质大DNA病毒（NCLDVs）科：痘病毒科、虹彩病毒科、疱疹病毒科以及巨病毒科。与之前的研究结果相反，在这些大堡礁珊瑚中，杆状病毒很罕见。在3种珊瑚物种中观察到了一种与双RNA病毒相似的单链RNA病毒的序列，双RNA病毒是一种感染自由生活甲藻的单链RNA病毒。我们还检测到了此前未在珊瑚共生体中发现的病毒，包括一种靶向与该珊瑚物种相关真菌的病毒。对组装重叠群的功能分析表明，与珊瑚相关的病毒群落中潜伏相关基因普遍存在，还有几个宿主来源的参与光合作用的辅助代谢基因（AMGs）（分别是编码光系统II D1和D2蛋白的psbA和psbD基因），以及潜在的刺细胞毒素和抗氧化剂（编码绿色荧光样色素蛋白的基因）。这项研究通过描述7种大堡礁珊瑚物种的病毒组成和功能，扩展了目前关于珊瑚相关病毒的有限知识。
