Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-19056 - Expression data of Actinobacillus pleuropneumoniae 4074 and the ΔluxS mutant of Actinobacillus pleuropneumoniae 4074
Released on 9 November 2011, last updated on 27 June 2012
LuxS is an enzyme involved in the activated methyl cycle and the by-product autoinducer 2 (AI-2) was a quorum sensing signal in some species. In our previous study, the functional LuxS in AI-2 production was verified in the porcine respiratory pathogen Actinobacillus pleuropneumoniae. Enhanced biofilm formation and reduced virulence were observed in the luxS mutant. To comprehensively understand the luxS function, in this study, the transcriptional profiles were compared between the A. pleuropneumoniae luxS mutant and its parental strain in four different growth phases using microarray. Many genes associated with infection were differentially expressed. The biofilm formation genes pgaABC in the luxS mutant were up-regulated in early exponential phase, while 8 genes associated with adhesion were down-regulated in late exponential phase. A group of genes involved in iron acquisition and metabolism were regulated in four growth phases. Further investigations on these virulence traits demonstrated that the luxS mutant showed enhanced biofilm formation and reduced adhesion ability and these effects were not due to lack of AI-2. But AI-2 could increase biofilm formation and adhesion of A. pleuropneumoniae independent of LuxS. Growth under iron restricted condition could be controlled by LuxS through AI-2 production. These results revealed pleiotropic roles of LuxS and AI-2 on A. pleuropneumoniae virulence traits. A. pleuropneumoniae strains were cultured in TSB medium supplemented with 10 μg/ml of nicotinamide adenine dinucleotide (NAD) and 10% (v/v)filtered cattle serum at 37°C. The samples were collected from early exponential phase, middle exponential phase, late exponential phase and stationary phase respectively and the total RNA were extracted using RNA-Solv Reagent (Omega) according to the manufacturer’s instructions. For each time point, four biological replicates were combined into two samples. The intensities were normalized and transformed into log2 value.The fold changes >=1.5 or <=-1.5 were selected as differentially expressed genes.
transcription profiling by array
Huanchun Chen, Lu Li, Rui Zhou, Zhuofei Xu
Analysis on Actinobacillus pleuropneumoniae LuxS regulated genes reveals pleiotropic roles of LuxS/AI-2 on biofilm formation, adhesion ability and iron metabolism. Li L, Xu Z, Zhou Y, Li T, Sun L, Chen H, Zhou R. , PMID:21320583