title: The phasevarion: a genetic system controlling coordinated, random switching of expression of multiple genes.
abstract: Several host-adapted bacterial pathogens contain methyltransferases associated with type III restriction-modification (R-M) systems that are subject to reversible, high-frequency on/off switching of expression (phase variation). To investigate the role of phase-variable expression of R-M systems, we made a mutant strain lacking the methyltransferase (mod) associated with a type III R-M system of Haemophilus influenzae and analyzed its phenotype. By microarray analysis, we identified a number of genes that were either up- or down-regulated in the mod mutant strain. This system reports the coordinated random switching of a set of genes in a bacterial pathogen and may represent a widely used mechanism.
authors.affiliation: School of Molecular and Microbial Science and Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Yogitha N
authors.initials: YN
authors.lastname: Srikhanta
authors.forename: Tina L
authors.initials: TL
authors.lastname: Maguire
authors.forename: Katryn J
authors.initials: KJ
authors.lastname: Stacey
authors.forename: Sean M
authors.initials: SM
authors.lastname: Grimmond
authors.forename: Michael P
authors.initials: MP
authors.lastname: Jennings
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D018387:Codon, Initiator / Q000235:genetics; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D006193:Haemophilus influenzae / Q000166:cytology / Q000201:enzymology / Q000235:genetics* / Q000276:immunology; D006360:Heat-Shock Proteins / Q000235:genetics; D018869:Heat-Shock Response; D006790:Host-Parasite Interactions; D008262:Macrophage Activation; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype
chemical_list: D001426:Bacterial Proteins; D018387:Codon, Initiator; D004269:DNA, Bacterial; D006360:Heat-Shock Proteins; D015254:DNA Modification Methylases