细菌中基因组岛的转移与调控机制研究进展

Regulation, excision and horizontal transfer of genomic islands in bacteria

摘要:

基因水平转移可导致细菌不同种属间个体DNA的交换，从而使细菌对环境的适应性增强，是细菌进化的重要途径之一。基因组岛是基因水平转移的重要载体，可移动的基因组岛能够整合到宿主的染色体上，并在特定的条件下切除，进而通过转化、接合或转导等方式转移到新的宿主中。基因组岛具有多种生物学功能，如抗生素抗性、致病性、异源物质降解、重金属抗性等。基因组岛的转移造成可变基因在不同种属细菌间的广泛传播，例如毒力和耐药基因的传播导致了多重耐药细菌的产生，威胁人类健康。基因组岛由整合酶介导转移，同时在转移的过程受到多种不同转录因子的调控。本文对细菌中基因组岛的结构特点、转移和调控机制以及预测等方面进行了综述，并最终阐明基因组岛的转移及其调控机制是遏制基因组岛传播的重要策略。

Abstract:

Horizontal gene transfer (HGT) is a common mechanism for the exchange of genetic information between bacterial species, which contributes to the diversification and adaptation of microorganisms. Mobile genetic elements (MGEs), the drivers of HGT, are segments of DNA that encode enzymes and other proteins that mediate the movement of DNA within genomes (intracellular mobility) or between bacterial cells (intercellular mobility). Genomic island is an important MGE in bacteria. Mobile genomic islands are able to integrate into the chromosome of the host, from which they get excised under favorable conditions and are then transferred to a new host via transformation, conjugation or transduction. Genomic islands have a variety of biological function, such as antibiotic resistance, pathogenicity, xenobiotic degradation and heavy metal resistance. Genomic islands are mediated by integrase and regulated by diverse transcription factors in the process of metastasis. In this review, we evaluate the progress in regulation, excision and horizontal transfer of genomic islands in bacteria.