Expression analysis of a full Lsr locus knockout on the luxS knockout background of Haemophilus influenzae strain CZ4126/02

Investigation of whole genome gene expression differences between a full (nine-gene) Lsr locus deletion and a luxS deletion strain (double knock-out) compared to a luxS isogenic mutant strain (each derived from the CZ4126/02 parent strain). Both strains are unable to produce the autoinducer-2 (AI-2) quorum sensing molecule. In addition, the Lsr mutant is unable to import AI-2 nor mediate any potential LsrR-based transcriptional regulation. ΔluxS and ΔlsrΔluxS strains were grown in a chemically defined media (CDM) to two different time-points with or without the addition of 3µM synthetic AI-2. RNA was extracted from these sampling conditions in two separate cultures (biological replicates). Each of these RNA samples was run on two different H. influenzae supragenome arrays (technical replicates). 3-13 probes represent each subcluster(gene) and two replicate probe sets are included on each custom NTHi supragenome chip thus under each sampling condition 8 separate values are obtained per strain and used for WT:Lsr-KO comparisons.