Project description:Transcription profiling of wild type E. coli MG1655, intestine-adapted E. coli MG1655star, and E. coli MG1655 flhD mutant grown on glucose, mannose, and mucus. We previously isolated a spontaneous mutant of E. coli K-12, strain MG1655, following passage through the streptomycin-treated mouse intestine, which has colonization traits superior to the wild-type parent strain (Leatham, et. al., 2005, Infect Immun 73:8039-49) The intestine-adapted strain (E. coli MG1655star) grew faster on several different carbon sources compared to the wild-type and was non-motile due to deletion of the flhD gene. To further characterize E. coli MG1655star, we used several high-throughput genomic approaches. Whole-genome pyrosequencing did not reveal any changes on its genome, aside from the deletion at the flhDC locus, that could explain the colonization advantage of E. coli MG1655star. Microarray analysis revealed modest, yet significant induction of catabolic gene systems across the genome in both E. coli MG1655star and the isogenic flhD mutant. Catabolome analysis with Biolog GN2 Microplates revealed an enhanced ability of both E. coli MG1655star and the isogenic flhD mutant to oxidize a wide variety of carbon sources. The results show that intestine-adapted E. coli MG1655star is more fit than the wild-type for intestinal colonization because loss of FlhD results in elevated expression of genes involved in carbon and energy metabolism, leading to more efficient carbon source utilization, which results in a higher population size in the intestine. Hence mutations that enhance metabolic efficiency confer a colonization advantage.
Project description:Transcription profiling of wild type E. coli MG1655, intestine-adapted E. coli MG1655star, and E. coli MG1655 flhD mutant grown on glucose, mannose, and mucus. We previously isolated a spontaneous mutant of E. coli K-12, strain MG1655, following passage through the streptomycin-treated mouse intestine, which has colonization traits superior to the wild-type parent strain (Leatham, et. al., 2005, Infect Immun 73:8039-49) The intestine-adapted strain (E. coli MG1655star) grew faster on several different carbon sources compared to the wild-type and was non-motile due to deletion of the flhD gene. To further characterize E. coli MG1655star, we used several high-throughput genomic approaches. Whole-genome pyrosequencing did not reveal any changes on its genome, aside from the deletion at the flhDC locus, that could explain the colonization advantage of E. coli MG1655star. Microarray analysis revealed modest, yet significant induction of catabolic gene systems across the genome in both E. coli MG1655star and the isogenic flhD mutant. Catabolome analysis with Biolog GN2 Microplates revealed an enhanced ability of both E. coli MG1655star and the isogenic flhD mutant to oxidize a wide variety of carbon sources. The results show that intestine-adapted E. coli MG1655star is more fit than the wild-type for intestinal colonization because loss of FlhD results in elevated expression of genes involved in carbon and energy metabolism, leading to more efficient carbon source utilization, which results in a higher population size in the intestine. Hence mutations that enhance metabolic efficiency confer a colonization advantage. Three strains were profiled: E. coli MG1655 wildtype, E. coli flhD, and an intestine adapted strain, MG1655star, derived from the wildtype and isolated from feces after 15 days in the streptomycin treated mouse intestine, which proved to be a better colonizer than the wildtype, were grown on MOPS minimal medium containing 0.2% glucose or mannose, or mucus (10 mg/ml) and RNA was extracted from logarithmic phase cultures, and also from mucus grown cells in late log phase.
Project description:Expression profiles of wild-type and SgrR mutant E. coli strains under aMG and 2-DG-induced stress. Expression profiles of E. coli overexpressing SgrS sRNA.
Project description:Expression profiles of wild-type and SgrR mutant E. coli strains under aMG and 2-DG-induced stress. Expression profiles of E. coli overexpressing SgrS sRNA. Illumina RNA-Seq of total RNA extracted from wild-type, SgrR/SgrS mutant and SgrS overexpressing E. coli strains grown in different conditions.
Project description:Mature tRNA pools were measured using an adaptation of YAMAT-seq (Shigematsu et al., 2017; doi:10.1093/nar/gkx005 ) and further described in (Ayan et al., 2020; doi:10.7554/eLife.57947) in 10 strain-medium combinations (all strains dervied from the model bacterium E. coli MG1655). The aim of the experiment was to investigate the effect of reducing tRNA gene copy number on mature tRNA pools in rich and poor media.