title: The CRISPR-Cas Immune System and Genetic Transfers: Reaching an Equilibrium.
abstract: 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.
authors.affiliation: 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.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Samson
authors.affiliation: 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.
authors.forename: Alfonso H
authors.initials: AH
authors.lastname: Magadan
authors.affiliation: 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.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Moineau
mesh_terms: D001419:Bacteria / Q000235:genetics*; D064113:CRISPR-Cas Systems; D003227:Conjugation, Genetic; D004247:DNA / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D020071:Interspersed Repetitive Sequences; D014170:Transformation, Genetic
chemical_list: D004247:DNA