Département de Biochimie, Microbiologie et Bio-Informatique, Faculté des Sciences et de Génie, Groupe de Recherche en Écologie Buccale, Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de Médecine Dentaire, Université Laval, Québec City, Québec, G1V 0A6, Canada.
Microbiol Spectr. 2015 Feb;3(1):PLAS-0034-2014. doi: 10.1128/microbiolspec.PLAS-0034-2014.
Horizontal gene transfer drives the evolution of bacterial genomes, including the adaptation to changing environmental conditions. Exogenous DNA can enter a bacterial cell through transformation (free DNA or plasmids) or through the transfer of mobile genetic elements by conjugation (plasmids) and transduction (bacteriophages). Favorable genes can be acquired, but undesirable traits can also be inadvertently acquired through these processes. Bacteria have systems, such as clustered regularly interspaced short palindromic repeat CRISPR-associated genes (CRISPR-Cas), that can cleave foreign nucleic acid molecules. In this review, we discuss recent advances in understanding CRISPR-Cas system activity against mobile genetic element transfer through transformation and conjugation. We also highlight how CRISPR-Cas systems influence bacterial evolution and how CRISPR-Cas components affect plasmid replication.
水平基因转移推动了细菌基因组的进化，包括对环境变化条件的适应。外源性 DNA 可以通过转化（游离 DNA 或质粒）或通过接合（质粒）和转导（噬菌体）转移移动遗传元件进入细菌细胞。有利的基因可以被获得，但通过这些过程也可能无意中获得不良性状。细菌具有可以切割外来核酸分子的系统，如成簇规律间隔短回文重复 CRISPR 相关基因 (CRISPR-Cas)。在这篇综述中，我们讨论了最近对理解 CRISPR-Cas 系统在转化和接合过程中对抗移动遗传元件转移的活性的研究进展。我们还强调了 CRISPR-Cas 系统如何影响细菌进化，以及 CRISPR-Cas 成分如何影响质粒复制。
