Project description:We investigated the anode-specific responses of Shewanella oneidensis MR-1, an exoelectroactive ammaproteobacterium, using for the first time iTRAQ and 2D-LC MS/MS driven membrane proteomics to compare protein abundances in S. oneidensis when generating power in MFCs, and growing in a continuous culture.
Project description:The sumitted data compares gene expression profile of Shewnaella oneidensis MR-1 on two different sets of media conditions (nutritionally rich LB medium and Lactate minimal medium) To explore the effect of various growth phases in Shewanella oneidensis MR-1, the genome-wide transcriptome profiles growth in two sets media was compared to each other. Strain was grown in chemostat at 20% O2 in batch culture. Samples were collected in duplicate from both experiments.
Project description:We combined high-resolution tiling microarrays and 5'-end RNA sequencing to obtain a genome-wide map of transcription start sites (TSSs) for Shewanella oneidensis MR-1. To test the reliability of these TSSs, we compared our result to those from differential RNA sequencing (dRNA-seq), which discriminates primary and processed ends of transcripts. We found that our identified TSSs tend to have significantly more mapped reads in the TEX(+) sample than the TEX(-) sample. Overall, the dRNA-seq results support the validity of our predictions for TSS.
Project description:Comparison of gene expression and mutant fitness in Shewanella oneidensis MR-1 Expression data for 15 growth conditions in mid-exponential phase and expression data across growth phases for 3 of those conditions
Project description:The ionizing radiation (IR) dose that yields 20% survival (D20) of Shewanella oneidensis MR-1 is lower by factors of 20 and 200 than for Escherichia coli and Deinococcus radiodurans, respectively. Transcriptome analysis was used to identify the genes of MR-1 responding to 40 Gy (D20). We observed the induction of 170 genes and repression of 87 genes in MR-1 during a one-hour recovery period after irradiation. The genomic response of MR-1 to IR is very similar to its response to ultraviolet radiation (254 nm), which included induction of systems involved in DNA repair and prophage synthesis, and the absence of differential regulation of tricarboxylic acid cycle activity which occurs in IR-irradiated D. radiodurans. Furthermore, strong induction of genes encoding antioxidant enzymes in MR-1 was observed. DNA damage may not be the principal cause of high sensitivity to IR considering that MR-1 encodes a complex set of DNA repair systems and 40 Gy IR induces less than one double strand break (DSB) in its genome. Instead, a combination of oxidative stress, protein damage and prophage mediated cell lysis during irradiation and recovery might underlie this organism’s great sensitivity to radiation. Keywords: time course, stress response
Project description:We combined high-resolution tiling microarrays and 5'-end RNA sequencing to obtain a genome-wide map of transcription start sites (TSSs) for Shewanella oneidensis MR-1. To test the reliability of these TSSs, we compared our result to those from differential RNA sequencing (dRNA-seq), which discriminates primary and processed ends of transcripts. We found that our identified TSSs tend to have significantly more mapped reads in the TEX(+) sample than the TEX(-) sample. Overall, the dRNA-seq results support the validity of our predictions for TSS. S. oneidensis MR-1 was grown to mid-log phase in Luria-Bertani broth (LB) or defined lactate minimal medium, and total RNA was isolated and used for differential RNA-sequencing (dRNA-seq) by next-generation sequencing, which is used to verify genome-wide transcription start sites. For dRNA-seq, total RNA was partially treated with Terminator Exonuclease (TEX) to digest processed RNA and thereby enrich for primary transcript ends.
Project description:Comparisson of expression profiling of a etrA deletion mutant strain (experimental sample) with that of the wild type Shewanella oneidensis MR-1 strain to assess global direct/indirect genetic regulation EtrA in Shewanella oneidensis MR-1 shares 73.6% and 50.8% amino acid sequence identity with the oxygen-sensing regulator Fnr in E. coli and Anr in Pseudomonas aeruginosa, respectively; however, its regulatory role of anaerobic metabolism in Shewanella spp. is complex and not well understood. Whole-genome expression profiling using a etrA gene deletion mutant as the experimental sample and the wild type strain as the reference, determine that EtrA fine-tunes the expression of genes involved in various anaerobic metabolic pathways, including nitrate, fumarate and dimethyl sulfoxide reduction. Moreover, genes involved in prophage activation and and genes implicated in aerobic metabolism were also differentially expressed. In contrast to previous studies that attributed a minor regulatory role to EtrA in Shewanella spp., this study demonstrates that EtrA acts as a global transcriptional regulator and cofers physiological advantages to the strain under certain growth conditions.