title: Microarray-based characterization of the Listeria monocytogenes cold regulon in log- and stationary-phase cells.
abstract: Whole-genome microarray experiments were performed to define the Listeria monocytogenes cold growth regulon and to identify genes differentially expressed during growth at 4 and 37 degrees C. Microarray analysis using a stringent cutoff (adjusted P < 0.001; >/=2.0-fold change) revealed 105 and 170 genes that showed higher transcript levels in logarithmic- and stationary-phase cells, respectively, at 4 degrees C than in cells grown at 37 degrees C. A total of 74 and 102 genes showed lower transcript levels in logarithmic- and stationary-phase cells, respectively, grown at 4 degrees C. Genes with higher transcript levels at 4 degrees C in both stationary- and log-phase cells included genes encoding a two-component response regulator (lmo0287), a cold shock protein (cspL), and two RNA helicases (lmo0866 and lmo1722), whereas a number of genes encoding virulence factors and heat shock proteins showed lower transcript levels at 4 degrees C. Selected genes that showed higher transcript levels at 4 degrees C during both stationary and log phases were confirmed by quantitative reverse transcriptase PCR. Our data show that (i) a large number of L. monocytogenes genes are differentially expressed at 4 and 37 degrees C, with more genes showing higher transcript levels than lower transcript levels at 4 degrees C, (ii) L. monocytogenes genes with higher transcript levels at 4 degrees C include a number of genes and operons with previously reported or plausible roles in cold adaptation, and (iii) L. monocytogenes genes with lower transcript levels at 4 degrees C include a number of virulence and virulence-associated genes as well as some heat shock genes.
authors.affiliation: Department of Food Science, Cornell University, Ithica, NY 14853, USA. mw16@cornell.edu
authors.forename: Yvonne C
authors.initials: YC
authors.lastname: Chan
authors.forename: Sarita
authors.initials: S
authors.lastname: Raengpradub
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Boor
authors.forename: Martin
authors.initials: M
authors.lastname: Wiedmann
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D015169:Colony Count, Microbial; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D018869:Heat-Shock Response; D008089:Listeria monocytogenes / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D018085:Regulon; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D001426:Bacterial Proteins