Abstract:
Non-lytic viruses with enveloped pleomorphic virions (family Pleolipoviridae) are ubiquitous in hypersaline environments across the globe and are associated with nearly all major lineages of halophilic archaea. However, their existence in other ecosystems remains largely unknown. Here, we show that evolutionarily-related viruses also infect hyperthermophilic archaea thriving in deep-sea hydrothermal vents. Archaeoglobus veneficus pleomorphic virus 1 (AvPV1), the first virus described for any member of the class Archaeoglobi, encodes a morphogenetic module typical of pleolipoviruses, including the characteristic VP4-like membrane fusion protein. We show that AvPV1 is a non-lytic virus chronically produced in liquid cultures without substantially affecting the growth dynamics of its host with a stable virus-to-host ratio of ~1. Mining of genomic and metagenomic databases revealed broad distribution of AvPV1-like viruses in geographically remote hydrothermal vents. Comparative genomics, coupled with phylogenetic analysis of VP4-like fusogens revealed deep divergence of pleomorphic viruses infecting halophilic, methanogenic, and hyperthermophilic archaea, signifying niche separation and coevolution of the corresponding virus-host pairs. Hence, we propose a new virus family, \"Thalassapleoviridae,\" for classification of the marine hyperthermophilic virus AvPV1 and its relatives. Collectively, our results provide insights into the diversity and evolution of pleomorphic viruses beyond hypersaline environments.
摘要:
具有包膜多形性病毒体(Pleolipoviridae家族)的非裂解病毒在全球高盐环境中普遍存在,并且与嗜盐古细菌的几乎所有主要谱系有关。然而,它们在其他生态系统中的存在在很大程度上仍然未知。这里,我们表明,进化相关的病毒也感染在深海热液喷口中蓬勃发展的超嗜热古细菌。盘古古细菌多形性病毒1(AvPV1),第一个病毒被描述为任何类的成员,编码典型的多囊病毒的形态发生模块,包括特征性的VP4样膜融合蛋白。我们表明,AvPV1是一种在液体培养物中长期产生的非裂解病毒,而不会实质上影响其宿主的生长动力学,稳定的病毒与宿主之比为〜1。基因组和宏基因组数据库的挖掘显示,类AvPV1病毒在地理上偏远的热液喷口中分布广泛。比较基因组学,结合VP4样融合菌的系统发育分析,揭示了感染嗜盐的多形病毒的深度分歧,产甲烷,和超嗜热古细菌,标志着相应病毒-宿主对的生态位分离和协同进化。因此,我们提出了一个新的病毒家族,\"Thalassapleoviridae\",用于海洋嗜热病毒AvPV1及其亲属的分类。总的来说,我们的结果为超盐环境之外的多形性病毒的多样性和进化提供了见解。