The major difference between viruses and plasmids is the mechanism of transferring their genomic information between host cells. Here, we describe the archaeal plasmid pR1SE from an Antarctic species of haloarchaea that transfers via a mechanism similar to a virus. pR1SE encodes proteins that are found in regularly shaped membrane vesicles, and the vesicles enclose the plasmid DNA. The released vesicles are capable of infecting a plasmid-free strain, which then gains the ability to produce plasmid-containing vesicles. pR1SE can integrate and replicate as part of the host genome, resolve out with fragments of host DNA incorporated or portions of the plasmid left behind, form vesicles and transfer to new hosts. The pR1SE mechanism of transfer of DNA could represent the predecessor of a strategy used by viruses to pass on their genomic DNA and fulfil roles in gene exchange, supporting a strong evolutionary connection between plasmids and viruses.

中文翻译：

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来自南极盐古生菌的质粒使用专门的膜囊泡传播和感染无质粒的细胞。

病毒和质粒之间的主要区别是在宿主细胞之间转移其基因组信息的机制。在这里，我们描述了从古埃及南极物种的古细菌质粒pR1SE，其通过类似于病毒的机制进行转移。pR1SE编码在规则形状的膜小泡中发现的蛋白质，小泡将质粒DNA包裹起来。释放的囊泡能够感染无质粒的菌株，然后获得产生含有质粒的囊泡的能力。pR1SE可以整合并复制为宿主基因组的一部分，用掺入的宿主DNA片段或残留的质粒部分分解出来，形成囊泡并转移到新的宿主中。