title: Homologous recombination between a lactococcal bacteriophage and the chromosome of its host strain.
abstract: Genetic exchanges constitute a significant means by which bacteriophages acquire novel characteristics. Phages of Lactococcus lactis occupy a particular niche, the dairy factory environment, where their populations are subjected to constant changes. Little is known about the mechanisms of evolution that lead to the genetic diversity of lactococcal phages. In this study, we described two DNA exchanges involving the lytic phage ul36, a member of the P335 species, and its L. lactis host. They occurred by homologous recombination with phage-related sequences present in the host chromosome. Both mutants generated by these recombination events are insensitive to the phage resistance mechanism AbiK and one has a reduced burst size as well as a new origin of replication. We propose that this type of DNA exchange with prophages or remnants of prophages occurs frequently within the P335 species as supported by DNA-DNA comparisons between P335-like phages.
authors.affiliation: Department of Biochemistry and Microbiology, Faculté des Sciences et de Génie, Québec, G1K 7P4, Canada.
authors.forename: J D
authors.initials: JD
authors.lastname: Bouchard
authors.forename: S
authors.initials: S
authors.lastname: Moineau
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D001435:Bacteriophages / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification / Q000648:ultrastructure; D001483:Base Sequence; D015139:Blotting, Southern; D002876:Chromosomes, Bacterial / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D016679:Genome, Viral; D013294:Lactococcus lactis / Q000235:genetics* / Q000821:virology*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D016366:Open Reading Frames / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics*; D018741:Replication Origin / Q000235:genetics; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D016662:Virus Integration / Q000235:genetics; D014779:Virus Replication
chemical_list: C106520:AbiK protein, Lactococcus lactis; D001426:Bacterial Proteins; D004279:DNA, Viral