Hypersaline environments are the source of many viruses infecting different species of halophilic euryarchaea. Information on infection mechanisms of archaeal viruses is scarce, due to the lack of genetically accessible virus-host models. Recently a new archaeal siphovirus, Haloferax tailed virus 1 (HFTV1), was isolated together with its host belonging to the genus Haloferax, but it is not infectious on the widely used model euryarcheon Hfx. volcanii. To gain more insight into the biology of HFTV1 host strain LR2-5, we studied characteristics that might play a role in its virus susceptibility: growth-dependent motility, surface layer, filamentous surface structures and cell shape. Its genome sequence showed that LR2-5 is a new strain of Hfx. gibbonsii. LR2-5 lacks obvious viral defense systems, such as CRISPR-Cas, and the composition of its cell surface is different from Hfx. volcanii, which might explain the different viral host range. This work provides first deep insights into the relationship between the host of halovirus HFTV1 and other members of the genus Haloferax. Given the close relationship to the genetically accessible Hfx. volcanii, LR2-5 has high potential as a new model for virus-host studies in euryarchaea.

中文翻译：

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姬鼠Halferax gibbonsii LR2-5的细胞和基因组特性

高盐环境是感染不同种类的嗜盐欧亚古细菌的许多病毒的来源。由于缺乏遗传上可及的病毒宿主模型，有关古细菌病毒感染机制的信息很少。最近，分离了一种新的古细菌siphovirus，Haloferax尾病毒1（HFTV1）及其宿主属于Haloferax属，但在广泛使用的euryarcheon Hfx模型上没有传染性。火山。为了深入了解HFTV1宿主菌株LR2-5的生物学特性，我们研究了可能在其病毒易感性中起作用的特征：依赖于生长的运动性，表面层，丝状表面结构和细胞形状。它的基因组序列表明LR2-5是Hfx的新菌株。长臂猿 LR2-5缺乏明显的病毒防御系统，例如CRISPR-Cas，而且其细胞表面的组成不同于Hfx。火山，这可能解释了不同的病毒宿主范围。这项工作提供了第一份深刻的见解，对晕病毒HFTV1的宿主和Haloferax属的其他成员之间的关系。考虑到与遗传可及的Hfx的密切关系。LR2-5在火山中具有很高的潜力，可以作为在欧洲原虫中进行病毒宿主研究的新模型。