Haloarchaeon Natrinema sp. J7, the first reported archaeon harboring both plasmid and chromosome-based temperate viruses, is a useful model for investigating archaeal virus-host and virus-virus interactions. However, the lack of genetic tools has limited such studies. On the basis of the automatically replicating sequences of the J7 chromosome and the pyrF marker, we constructed seven vectors, six of which were confirmed to possess replication ability in a pyrF-deletion derivative of J7 (J7-F). Among these vectors, pFJ1, pFJ4, and pFJ6 could be transformed into the host strain with relatively high efficiency (approximately 10³ colony-forming units/μg DNA) and were present at about one copy per chromosome. These three vectors could be stably maintained in J7-F without selection and were used for heterologous protein expression. Only pFJ6 was found to be present in the transformed cells in an exclusively episomal, nonintegrated state (one copy per chromosome). In contrast, some pFJ1 and pFJ4 DNA was probably integrated into the J7-F chromosome. In addition, pFJ6 was found to be compatible with pYCJ in J7 cells, suggesting that these two vectors could be used for further studies of virus-virus and virus-host interactions.

中文翻译：

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Haloarchaeon Natrinema sp。表达穿梭载体的构建。J7基于其复制的染色体起源。

Haloarchaeon Natrinema sp。J7是第一个报道的既包含质粒又基于染色体的温带病毒的古细菌，它是研究古细菌与宿主和病毒与病毒相互作用的有用模型。然而，缺乏遗传工具限制了此类研究。根据J7染色体的自动复制序列和pyrF标记，我们构建了七个载体，其中六个被证实具有J7的pyrF缺失衍生物（J7-F）的复制能力。在这些载体中，pFJ1，pFJ4和pFJ6可以以相对较高的效率（约10 ^3个菌落形成单位/ μ）转化到宿主菌株中。g DNA），并且每个染色体大约存在一个拷贝。这三个载体无需选择就可以稳定地维持在J7-F中，并用于异源蛋白表达。发现仅pFJ6以纯游离型，非整合状态（每个染色体一个拷贝）存在于转化细胞中。相反，一些pFJ1和pFJ4 DNA可能已整合到J7-F染色体中。另外，发现pFJ6与J7细胞中的pYCJ相容，表明这两个载体可用于病毒-病毒和病毒-宿主相互作用的进一步研究。