Project description:Through 8 generations of selection, our group has developed a strain of rainbow trout that exhibits high growth rates on an economically and environmentally sustainable all plant protein, high-soy diet. The selected strain also shows superior performance in bacterial and viral disease challenges compared to commercial trout strains, and even a strain specifically selected over many generations for viral and bacterial disease resistance. The selection criteria was strictly focused on performance on plant-based diets, and therefore the physiological mechanisms responsible for the strain’s superior disease resistance remain unresolved. To better characterize the physiological mechanism behind the superior performance of the selected strain we compared the intestinal gene expression of the select strain to that of a commercial control line of trout during an experimental bacterial infection with Flavobacterium psychrophilum (Fp) (CSF 259-93), the causative agent of bacterial cold water disease (BCWD) in salmonids. At 65 days post hatch, all female rainbow trout from the select and commercial strain were stocked separately into four 150L tanks each, at a density of 45 fish per tank. For both strains of trout, three tanks of fish were experimentally infected with Fp by intramuscular injection and one control tank was mock challenged by sham injection. Sampling was conducted at 5 days post challenge (dpc) (Early Infection) and 21 dpc (Late/Recovered Infection). Two intestinal samples from each tank were pooled and two pools from each tank were utilized for RNAseq library preparation. The select strain of trout showed significantly better survival rates (Log-Rank Test, p < 0.0001) over the 21 day infection period, with 70 and 95 % mortality among the select and commercial strain, respectively. Reads from the RNAseq samples were quantified at the transcript level prior to evaluating differential transcript usage and differential gene expression between the strains of trout, infection time points, and disease status.
Project description:X. oryzae pv. oryzae (Xoo) is the causal agent of bacterial blight of rice. X. oryzae pv. oryzicola (Xoc) is the causal agent of bacterial streak of rice. Fourteen day old rice leaves were inoculated with one of five strains of Xanthomonas oryzae. Seven strains of Xoo were used; three wild type strains (PXO99A, T7174, and PXO86) and strains PXO99AME7, which has a nonfunctional type III secretion system and is non-pathogenic, , PXO99AME1, a pthXo6 and avrXa27 double mutant, PXO99ME2, a pthXo1 mutant, and PXO99ME5, a reduced virulence strain with uncharacterized mutation in a TAL effector. One strain of Xoc (BLS303) was tested. Controls include an inoculation with water (MOCK) and no inoculation. T7174 is our label for the Japanese isolate MAFF311018. Third leaves are inoculated with a needless syringe at adjacent sites along the upper leaf blade. Six leaves from separate plants are pooled. RNA samples were collected 24 h after treatment. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Ginny Antony. The equivalent experiment is OS66 at PLEXdb.]
Project description:Purpose: We investigate the evolutionary footprints of a bacteria-plasmid association consisting of Escherichia coli K-12 MG1655 and plasmid RP4 undergoing a long-term sub-MIC antibiotic stress. Methods: Bacterial mRNA profiles of evolved RP4-carrying strains (E:H:p) and ancestral RP4-carrying strains (A:H:p) were generated by deep sequencing on an Illumina Hiseq platform. The sequence reads that passed quality filters were analyzed by Burrows–Wheeler Aligner (BWA), followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. qRT–PCR validation was performed using TaqMan and SYBR Green assays Results: Using an optimized data analysis workflow, we mapped about 15 million sequence reads of E:H:p and 12 million sequence reads of A:H:p to the E. coli MG1655 genome (GCF_000801205.1) and differential expressed genes were identified with TopHat workflow. RNA-seq data showed that approximately 15% of the transcripts showed differential expression between the E:H:p and A:H:p strains, with a fold change ≥1 and p value <0.005. Altered expression of 26 genes was confirmed with qRT–PCR, demonstrating the high degree of sensitivity of the RNA-seq method. Data analysis with bowtie and TopHat workflows provided complementary insights in transcriptome profiling. Conclusions: Our study showed the coevolved bacteria-plasmid pairs has colonization traits superior to the wild-type parent strain. Antibiotic stress was necessary for bacterial evolution and evolved strains mostly employed transcriptional modifications to reduce plasmid-related cost in evolutionary adaptations. Several genes related to chromosome-encoded efflux pumps were transcriptionally upregulated, while most plasmid-harboring genes were downregulated based on RNA gene sequencing. These transcriptional modifications endowed evolved strains with resistant phenotype modifications, including the enhanced bacterial growth and biofilm formation.
Project description:We performed RNA-Seq of leaves of Oryza sativa L. ssp. japonica cv. Nipponbare 48 hours after inoculation with 10 geographically diverse strains of Xanthomonas oryzae pv. oryzicola, the causal agent of bacterial leaf streak. Results provide insight into the molecular basis of bacterial leaf streak, particularly the role of transcription activator-like effectors in the disease. Examination of mRNA levels in Oryza sativa L. ssp. japonica cv. Nipponbare leaves at 48 hours after inoculation with 10 strains of Xanthomonas oryzae pv.oryzicola with three biological replicates for each compared to three replicates of mock inoculated O sativa as the control