LuxS/AI-2 quorum sensing microarray comparison in Yersinia pestis at 30°C

The AI-2 quorum-sensing system has been linked to diverse phenotypes and regulatory changes in pathogenic bacteria. In strain CO92, the AI-2 signal is produced in a luxS-dependent manner, reaching maximal levels of 2.5 μM in late logarithmic growth, and both wild type and pigmentation mutant strains made equivalent levels of AI-2. Y. pestis CO92 possesses a chromosomal lsr locus encoding factors involved in the binding and import of AI-2, and confirming this assignment, an lsr deletion increased extracellular pools of AI-2. To assess the functional role of AI-2 sensing in Y. pestis, microarray study was conducted comparing the ∆Pgm strain R88 to a ∆Pgm ∆luxS mutant at 30°C to mimic the flea gut. Six independent RNA samples from Y. pestis CO92 ΔPgm cultures were paired with six independent RNA samples from ΔPgm ΔluxS cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.