Project description: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.
Project description: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. M-NM-^TluxS and M-NM-^TlsrM-NM-^TluxS strains were grown in a chemically defined media (CDM) to two different time-points with or without the addition of 3M-BM-5M 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.
Project description:Investigation of whole genome gene expression differences in a full (nine-gene) Lsr locus knockout strain compared to the wild-type strain (CZ4126/02). This Lsr mutant is unable to import the autoinducer-2 (AI-2) quorum sensing molecule nor mediate any potential LsrR-based transcriptional regulation. WT and Lsr-KO strains were grown in two different media to two or three different time-points. 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.
Project description:Investigation of whole genome gene expression differences in a full (nine-gene) Lsr locus knockout strain compared to the wild-type strain (CZ4126/02). This Lsr mutant is unable to import the autoinducer-2 (AI-2) quorum sensing molecule nor mediate any potential LsrR-based transcriptional regulation.
Project description:Background: Haemophilus influenzae has an absolute aerobic growth requirement for heme and has developed multiple complex mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps remain to be elucidated. In a previous study we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those initial observations by determining the iron/heme regulons of two additional H. influenzae clinical isolates, i.e. the type b isolate 10810 and the nontypeable isolate R2866, to characterize the core iron/heme regulon of the species. Results: A microarray chip was designed to incorporate probes for all of the genes of H. influenzae isolates 10810 and R2866, and microarray studies were performed to compare gene expression under iron/heme-replete and iron/heme-restricted conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed. Of these 363 genes, 233 were maximally transcribed under iron/heme-replete conditions and 130 were preferentially transcribed in iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain10810, 351 were significantly differentially transcribed, 150 of these were preferentially transcribed in iron/heme-replete conditions and 201 were preferentially transcribed in iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes were similarly regulated in both isolates and that 74 of these also exhibited similar patterns of regulation in strain Rd KW20. Conclusion: This study provides evidence for a core of H. influenzae genes that are regulated by the availability of iron and/or heme in the growth environment. Elucidation of this core regulon provides targets for investigation of genes with an unrecognized role in iron and heme homeostasis, as well as other potential virulence determinants. In addition, the set of core genes potentially provides targets for therapeutic and vaccine designs since these products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body. This SuperSeries is composed of the following subset Series: GSE11349: Transcriptional profiling of FeHm effects on Haemophilus influenzae R2866 GSE11354: Transcriptional profiling of FeHm effects on Haemophilus influenzae 10810 Keywords: SuperSeries Refer to individual Series