Project description:To understand differences of gene expression profiles between Francisella strains RNA profiles of Francisella strains were generated by deep sequencing, in triplicate, using NovaSeq6000. qRT–PCR validation was performed using SYBR Green assays. Our study represents the first detailed differential transcriptomic analysis of Francisella strains , with biologic replicates, generated by RNA-seq technology.
Project description:We used an inhalation mouse model of infection to query a collection of 2149 mutants in a Francisella tularensis subsp. novicida background for genes required for growth, survival and systemic dissemination. A microarray-based genome-wide negative selection screen (Microarray tracking of transposon mutants = MATT) allowed us to monitor the behavior of transposon insertions in 1371 unique genes. Interestingly most of these genes persisted in lung and colonized liver and spleen. We found 44 (35%) genes negatively selected in lung and 81 (65%) genes negatively selected in liver and/or spleen. If negative selection in lung occurred, the attenuated mutants in general persisted at 24h after infection, disseminated to liver and/or spleen and appeared to be lost in lung after 48 to 72h of infection. These genes with a strong phenotype in lung but also potential for dissemination might be attractive vaccine or drug candidates. Keywords: Genome-Wide Negative Selection Screen
Project description:These samples are part of an experiment comparing the expression profiles of Francisella tularensis novicida grown in chemically defined medium and bacteria isolated 24 hours post infection of J774 macrophages to identify virulence factors
Project description:MglA is a transcriptional regulator of genes that contribute to the virulence of Francisella tularensis, a highly infectious pathogen and the causative agent of tularemia. This study used a label-free shotgun proteomics method to determine the F. tularensis subsp. novicida (F. novicida) proteins that are regulated by MglA. The differences in relative protein amounts between wild-type F. novicida and the mglA mutant were derived directly from the average peptide precursor ion intensity values measured with the mass spectrometer by using a suite of mathematical algorithms. Among the proteins whose relative amounts changed in an F. novicida mglA mutant were homologs of oxidative and general stress response proteins. The F. novicida mglA mutant exhibited decreased survival during stationary-phase growth and increased susceptibility to killing by superoxide generated by the redox-cycling agent paraquat. The F. novicida mglA mutant also showed increased survival upon exposure to hydrogen peroxide, likely due to increased amounts of the catalase KatG. Our results suggested that MglA coordinates the stress response of F. tularensis and is likely essential for bacterial survival in harsh environments.
Project description:These samples are part of an experiment comparing the expression profiles of Francisella tularensis novicida grown in chemically defined medium and bacteria isolated 24 hours post infection of J774 macrophages to identify virulence factors Custom microarray submitted previously was used as the platform (GPL20119). The samples submitted here were compared with samples submitted previously (GSM1673555-57 in GSE68478) and differentially expressed genes during the intra-macrophage growth were identified.
Project description:We used an inhalation mouse model of infection to query a collection of 2149 mutants in a Francisella tularensis subsp. novicida background for genes required for growth, survival and systemic dissemination. A microarray-based genome-wide negative selection screen (Microarray tracking of transposon mutants = MATT) allowed us to monitor the behavior of transposon insertions in 1371 unique genes. Interestingly most of these genes persisted in lung and colonized liver and spleen. We found 44 (35%) genes negatively selected in lung and 81 (65%) genes negatively selected in liver and/or spleen. If negative selection in lung occurred, the attenuated mutants in general persisted at 24h after infection, disseminated to liver and/or spleen and appeared to be lost in lung after 48 to 72h of infection. These genes with a strong phenotype in lung but also potential for dissemination might be attractive vaccine or drug candidates. Keywords: Genome-Wide Negative Selection Screen 185 arrays, no duplicates/replicates Filtered data (per organ/timepoint) provided as a supplementary file