The phage-inducible chromosomal islands (PICIs) are a family of highly mobile genetic elements that contribute substantively to horizontal gene transfer, host adaptation, and virulence. Initially identified in Staphylococcus aureus, these elements are now thought to occur widely in gram-positive bacteria. They are molecular parasites that exploit certain temperate phages as helpers, using a variety of elegant strategies to manipulate the phage life cycle and promote their own spread, both intra- and intergenerically. At the same time, these PICI-encoded mechanisms severely interfere with helper phage reproduction, thereby enhancing survival of the bacterial population. In this review we discuss the genetics and the life cycle of these elements, with special emphasis on how they interact and interfere with the helper phage machinery for their own benefit. We also analyze the role that these elements play in driving bacterial and viral evolution.

中文翻译：

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噬菌体诱导性染色体岛：高度进化的分子寄生物家族。

噬菌体可诱导的染色体岛（PICI）是一类高度可移动的遗传元件，它们对水平基因转移，宿主适应性和毒力有实质性贡献。最初在金黄色葡萄球菌中发现，现在认为这些元素广泛存在于革兰氏阳性细菌中。它们是利用某些温带噬菌体作为辅助分子的分子寄生虫，它使用各种优雅的策略来操纵噬菌体的生命周期并促进它们自身的传播，无论是在内部还是在内部。同时，这些PICI编码的机制严重干扰了辅助噬菌体的繁殖，从而提高了细菌种群的存活率。在这篇评论中，我们讨论了这些元素的遗传学和生命周期，特别强调它们如何相互作用和干扰辅助噬菌体机器，以实现自身利益。我们还分析了这些元素在驱动细菌和病毒进化中的作用。