Prediction, microarray and Northern blot analyses identify new intergenic small RNAs in Aliivibrio salmonicida
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ABSTRACT:
ORGANISM(S): Aliivibrio salmonicida LFI1238 Aliivibrio salmonicida
PROVIDER: GSE25558 | GEO | 2010/12/01
SECONDARY ACCESSION(S): PRJNA134279
REPOSITORIES: GEO
Similar Datasets
Project description:This SuperSeries is composed of the following subset Series: GSE25545: Prediction, microarray and Northern blot analyses identify new intergenic small RNAs in Aliivibrio salmonicida (LB medium vs. iron-limited condition) GSE25546: Prediction, microarray and Northern blot analyses identify new intergenic small RNAs in Aliivibrio salmonicida (wild type vs. LitR mutant) Refer to individual Series
2010-12-01 | E-GEOD-25558 | biostudies-arrayexpress
Project description:Bacterial small RNAs (sRNAs) are trans-encoded regulatory RNAs that typically bind mRNAs by short sequence complementarities and change the expression of the corresponding proteins. Some of the well characterized sRNAs serve critical steps in the regulation of important cellular processes, such as quorum sensing (Qrr), iron homeostasis (RyhB), oxidative stress (OxyS) and carbon metabolism (Spot42). However, many sRNAs remains to be identified, and the functional roles of sRNAs are known for only a small fraction. For example, of the hundreds of candidate sRNAs from members of the bacterial family Vibrionaceae the function is known for only nine. We have in this study significantly contributed to the discovery and verification of new sRNAs in a representative of Vibrioneceae, i.e., the A. salmonicida which causes severe disease in farmed Atlantic salmon and other fishes. A computational search for intergenic non-coding (nc) RNAs in the 4.6 Mb genome identified a total of 233 potential sRNAs and 19 other types of ncRNAs with homologs in Rfam. Depending on a set threshold value our microarray approach identified 50-80 sRNAs that are expressed under different growth conditions, twelve of which were verified by Northern blot analysis. In total our data identify nine previously unrecognized sRNAs.
2010-12-01 | GSE25546 | GEO
Project description:Bacterial small RNAs (sRNAs) are trans-encoded regulatory RNAs that typically bind mRNAs by short sequence complementarities and change the expression of the corresponding proteins. Some of the well characterized sRNAs serve critical steps in the regulation of important cellular processes, such as quorum sensing (Qrr), iron homeostasis (RyhB), oxidative stress (OxyS) and carbon metabolism (Spot42). However, many sRNAs remains to be identified, and the functional roles of sRNAs are known for only a small fraction. For example, of the hundreds of candidate sRNAs from members of the bacterial family Vibrionaceae the function is known for only nine. We have in this study significantly contributed to the discovery and verification of new sRNAs in a representative of Vibrioneceae, i.e., the A. salmonicida which causes severe disease in farmed Atlantic salmon and other fishes. A computational search for intergenic non-coding (nc) RNAs in the 4.6 Mb genome identified a total of 233 potential sRNAs and 19 other types of ncRNAs with homologs in Rfam. Depending on a set threshold value our microarray approach identified 50-80 sRNAs that are expressed under different growth conditions, twelve of which were verified by Northern blot analysis. In total our data identify nine previously unrecognized sRNAs.
2010-12-01 | GSE25545 | GEO
Project description:Bacterial small RNAs (sRNAs) are trans-encoded regulatory RNAs that typically bind mRNAs by short sequence complementarities and change the expression of the corresponding proteins. Some of the well characterized sRNAs serve critical steps in the regulation of important cellular processes, such as quorum sensing (Qrr), iron homeostasis (RyhB), oxidative stress (OxyS) and carbon metabolism (Spot42). However, many sRNAs remains to be identified, and the functional roles of sRNAs are known for only a small fraction. For example, of the hundreds of candidate sRNAs from members of the bacterial family Vibrionaceae the function is known for only nine. We have in this study significantly contributed to the discovery and verification of new sRNAs in a representative of Vibrioneceae, i.e., the A. salmonicida which causes severe disease in farmed Atlantic salmon and other fishes. A computational search for intergenic non-coding (nc) RNAs in the 4.6 Mb genome identified a total of 233 potential sRNAs and 19 other types of ncRNAs with homologs in Rfam. Depending on a set threshold value our microarray approach identified 50-80 sRNAs that are expressed under different growth conditions, twelve of which were verified by Northern blot analysis. In total our data identify nine previously unrecognized sRNAs. Two-condition experiment, wild type cells (control samples) vs. LitR mutants grown in LB medium (stimulated samples). Samples collected from three different optical densities (OD600nm 0.15, OD600nm 0.5 and OD600nm 0.8). Technical replicates for each sample point: 3 control, 3 stimulated, independently grown and harvested. One replicate per array.
2010-12-01 | E-GEOD-25546 | biostudies-arrayexpress
Project description:Bacterial small RNAs (sRNAs) are trans-encoded regulatory RNAs that typically bind mRNAs by short sequence complementarities and change the expression of the corresponding proteins. Some of the well characterized sRNAs serve critical steps in the regulation of important cellular processes, such as quorum sensing (Qrr), iron homeostasis (RyhB), oxidative stress (OxyS) and carbon metabolism (Spot42). However, many sRNAs remains to be identified, and the functional roles of sRNAs are known for only a small fraction. For example, of the hundreds of candidate sRNAs from members of the bacterial family Vibrionaceae the function is known for only nine. We have in this study significantly contributed to the discovery and verification of new sRNAs in a representative of Vibrioneceae, i.e., the A. salmonicida which causes severe disease in farmed Atlantic salmon and other fishes. A computational search for intergenic non-coding (nc) RNAs in the 4.6 Mb genome identified a total of 233 potential sRNAs and 19 other types of ncRNAs with homologs in Rfam. Depending on a set threshold value our microarray approach identified 50-80 sRNAs that are expressed under different growth conditions, twelve of which were verified by Northern blot analysis. In total our data identify nine previously unrecognized sRNAs. Two-condition experiment, cells grown in LB medium (control samples) vs. cells grown under iron-limited conditions (2,2`-dipyridyl) (stimulated samples). Samples collected from three different timepoints (15, 30 and 60 min). Technical replicates for each timepoint: 3 control, 3 stimulated, independently grown and harvested. One replicate per array.
2010-12-01 | E-GEOD-25545 | biostudies-arrayexpress
Project description:Here we provide a molecular description of a new psychrophilic strain, KCh11, of marine luminescent bacteria classified as Aliivibrio logei. We sequenced the entire lux operon of A. logei KCh1 and showed that it is substantially similar to the lux operon of Aliivibrio salmonicida. It was demonstrated that the reduced production of bioluminescence in A. salmonicida is most likely defined by a specific defect in its luxD gene.
| S-EPMC3147497 | biostudies-literature
Project description:BackgroundIron is an essential micronutrient for all living organisms, and virulence and sequestration of iron in pathogenic bacteria are believed to be correlated. As a defence mechanism, potential hosts therefore keep the level of free iron inside the body to a minimum. In general, iron metabolism is well studied for some bacteria (mostly human or animal pathogens). However, this area is still under-investigated for a number of important bacterial pathogens. Aliivibrio salmonicida is a fish pathogen, and previous studies of this bacterium have shown that production of siderophores is temperature regulated and dependent on low iron conditions. In this work we studied the immediate changes in transcription in response to a sudden decrease in iron levels in cultures of A. salmonicida. In addition, we compared our results to studies performed with Vibrio cholerae and Vibrio vulnificus using a pan-genomic approach.ResultsMicroarray technology was used to monitor global changes in transcriptional levels. Cultures of A. salmonicida were grown to mid log phase before the iron chelator 2,2'-dipyridyl was added and samples were collected after 15 minutes of growth. Using our statistical cut-off values, we retrieved thirty-two differentially expressed genes where the most up-regulated genes belong to an operon encoding proteins responsible for producing the siderophore bisucaberin. A subsequent pan-transcriptome analysis revealed that nine of the up-regulated genes from our dataset were also up-regulated in datasets from similar experiments using V. cholerae and V. vulnificus, thus indicating that these genes are involved in a shared strategy to mitigate low iron conditions.ConclusionsThe present work highlights the effect of iron limitation on the gene regulatory network of the fish pathogen A. salmonicida, and provides insights into common and unique strategies of Vibrionaceae species to mitigate low iron conditions.
| S-EPMC4324432 | biostudies-literature
Project description:Aliivibrio salmonicida causes “cold-water vibriosis” (or “Hitra disease”) in fish, including marine-reared Atlantic salmon. During development of the disease the bacterium will encounter macrophages with antibacterial activities such as production of damaging reactive oxygen species (ROS). To defend itself the bacterium will presumably start producing detoxifying enzymes, reducing agents, and proteins involved in DNA and protein repair systems. Even though responses to oxidative stress are well studied for a few model bacteria, little work has been done in general to explain how important groups of pathogens, like members of the Vibrionaceae family, can survive at high levels of ROS. We have used bioinformatic tools and an –omics approach to study how A. salmonicida responds to hydrogen peroxide (H2O2). First, we used the recently published genome sequence to predict potential binding sites for OxyR (H2O2 response regulator). The computer-based search identified OxyR sites associated with 20 single genes and 8 operons, and these predictions were compared to experimental data from Northern blot analysis, microarray analysis and 2D gel electrophoresis. In general, OxyR binding site predictions and experimental results are in agreement. Up- and down-regulated genes are distributed among all functional gene categories, but a striking number of ≥2 fold up-regulated genes encode proteins involved in detoxification or DNA protection and repair, are part of reduction systems, or are involved in carbon metabolism and regeneration of NADH/NADPH. Our predictions and –omics data corroborates well with findings from other model bacteria, but also suggest species-specific gene regulation.
2010-03-01 | GSE20082 | GEO
Project description:Expression profiling of a spf deletion mutant suggests biological roles and mRNA targets for Spot 42 in the fish pathogen Aliivibrio salmonicida
| PRJNA139739 | ENA