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GSE30692
Escherichia coli
2 Downloadable Samples
Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
Antitoxins are becoming recognized as proteins that regulate more than their own synthesis; for example, we found previously that antitoxin MqsA represses the gene encoding the stationary phase sigma factor RpoS. Here, we investigated the physiological role of antitoxin DinJ of the DinJ/YafQ toxin/antitoxin system and found DinJ also affects the general stress response by decreasing RpoS levels. Corroborating the reduced RpoS levels upon producing DinJ, catalase activity, cell adhesins, and cyclic diguanylate decreased while swimming increased. Using a transcriptome search and DNA-binding assays, we determined that the mechanism by which DinJ reduces RpoS is by repressing cspE which encodes cold-shock protein CspE that inhibits translation of rpoS mRNA. Hence, DinJ influences the general stress response indirectly by regulating cspE.
Publication Title
Antitoxin DinJ influences the general stress response through transcript stabilizer CspE.
Sample Metadata Fields
Time
View Samples- Escherichia coli k-12
- 2 Downloadable Samples
- Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
Persister cells are a sub-population of all bacterial cultures which exhibit a non-inheritable, multi-drug tolerance when subjected to lethal antibiotic challenge. These persisters arise as a result of metabolic dormancy, and can resume growth subsequent to antibiotic challenge, leading to recalcitrance of bacterial infections.
Publication Title
Phosphodiesterase DosP increases persistence by reducing cAMP which reduces the signal indole.
Sample Metadata Fields
No sample metadata fields
View Samples- Arabidopsis thaliana
- 21 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Exposure to high irradiance results in dramatic changes in nuclear gene expression in plants. However, little is known about the mechanisms by which changes in irradiance are sensed and how the information is transduced to the nucleus to initiate the genetic response. To investigate whether the photoreceptors are involved in the response to high irradiance, we analyzed expression of ELIP1, ELIP2, APX2 and LHCB2.4 in the phyA, phyB, cry1 and cry2 photoreceptor mutants and hy5 and hyh transcription factor mutants. Following exposure to high intensity white light for 3 h (HL, 1000 micro mol quanta m-2 s-1) expression of ELIP1/2 and APX2 was strongly induced and LHCB2.4 expression repressed in wild type. The cry1 and hy5 mutants showed specific mis-regulation of ELIP1/2 and we show that the induction of ELIP1/2 expression is mediated via CRY1 in a blue light intensity-dependent manner. Furthermore, using the Affymetrix Arabidopsis 24K Gene-Chip we showed that 77 of the HL responsive genes are regulated via CRY1, and 26 of those genes were also HY5 dependent. As a consequence of the mis-regulation of these genes the cry1 mutant displayed a high irradiance-sensitive phenotype with significant photoinactivation of PSII, indicated by reduced Fv/Fm. Thus, we describe a novel function of CRY1 in mediating plant responses to high irradiances that is essential to the induction of photoprotective mechanisms. This indicates that high irradiance can be sensed in a chloroplast-independent manner by a cytosolic/nucleic component.
Publication Title
Genome-wide gene expression analysis reveals a critical role for CRYPTOCHROME1 in the response of Arabidopsis to high irradiance.
Sample Metadata Fields
No sample metadata fields
View Samples- Escherichia coli
- 3 Downloadable Samples
- Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
E. coli K-12 BW25113 persister cells generated via H202 pre-treatment and deletion of rpoS, relative to BW25113 wild-type stationary phase gene expression. Persister cells were generated following exposure to ampicillin 20 ug/mL.
Publication Title
Bacterial persistence increases as environmental fitness decreases.
Sample Metadata Fields
Specimen part, Disease, Treatment, Time
View Samples- Escherichia coli k-12
- 2 Downloadable Samples
- Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
Persisters are a subpopulation of metabolically-dormant cells in biofilms that are resistant to antibiotics; hence, understanding persister cell formation is important for controlling bacterial infections. Previously we discerned that MqsR and MqsA of Escherichia coli are a toxin/antitoxin pair that influence persister cell production via their regulation of Hha, CspD, and HokA. Here, to gain more insights into the origin of persisters, we used protein engineering to increase the toxicity of toxin MqsR by reasoning it would be easier to understand the effect of this toxin if it were more toxic. We found that two mutations (K3N and N31Y) increase the toxicity four fold and increase persistence 73 fold compared to native MqsR by making the protein less labile. A whole transcriptome study revealed that the MqsR variant represses acid resistance genes (gadABCEWX and hdeABD), multidrug resistance genes (mdtEF), and osmotic resistance genes (osmEY). Corroborating these microarray results, deletion of rpoS as well as the genes that the master stress response regulator RpoS controls, gadB, gadX, mdtF, and osmY, increased persister formation dramatically to the extent that nearly the whole population became persistent. Therefore, the more toxic MqsR increases persistence by decreasing the ability of the cell to respond to antibiotic stress through its RpoS-based regulation of acid resistance, multidrug resistance, and osmotic resistance systems.
Publication Title
Bacterial persistence increases as environmental fitness decreases.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus
- 16 Downloadable Samples
- Affymetrix Mouse Genome 430A 2.0 Array (mouse430a2)
Description
Adiponectin is an adipose-derived hormone with anti-inflammatory activity. Following subacute ozone exposure (0.3 ppm for 24-72 h), pulmonary neutrophilic inflammation is augmented in adiponectin deficient mice. The purpose of this study was to use microarrays to examine the impact of adiponectin deficiency on changes in pulmonary gene expression induced by ozone, a common air pollutant.
Publication Title
Pivotal role of IL-6 in the hyperinflammatory responses to subacute ozone in adiponectin-deficient mice.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 6 Downloadable Samples
Illumina HiSeq 2500
Description
The Notch signalling pathway plays fundamental roles in diverse developmental processes in metazoans, where it is important in driving cell fate and directing differentiation of various cell types. However, we still have limited knowledge about the role of Notch in early preimplantation stages of mammalian development, or how it interacts with other signalling pathways active at these stages such as Hippo. By using genetic and pharmacological tools in vivo, together with image analysis of single embryos and pluripotent cell culture, we have found that Notch is active from the 4-cell stage. Transcriptomic analysis in single morula identified novel Notch targets, such as early naïve pluripotency markers or transcriptional repressors such as TLE4. Our results reveal a previously undescribed role for Notch in driving transitions during the gradual loss of potency that takes place in the early mouse embryo prior to the first lineage decisions. Overall design: Transcriptomic analysis comparing single Rbpj mutant and control mouse morulae. RNA was isolated from individual E2.5 embryos from two litters. 3 mutant and 3 control embryos were used for analysis.
Publication Title
Transitions in cell potency during early mouse development are driven by Notch.
Sample Metadata Fields
Specimen part, Subject
View Samples- Citrus sinensis
- 12 Downloadable Samples
- Affymetrix Citrus Genome Array (citrus)
Description
We have used the citrus GeneChip array (GPL5731) to survey the transcription profiles of sweet orange in response to the bacterial pathogens Xanthomonas axonopodis pv. citri (Xac) and Xanthomonas axonopodis pv. aurantifolii (Xaa). Xac is the causal agent of the citrus canker disease on a wide range of citrus species, including sweet oranges (Citrus sinensis). On the other hand, Xaa is pathogenic to Mexican lime (Citrus aurantifolia) only, and in sweet orange it triggers a defense response. In order to identify the genes induced during the defense response (Xaa-responsive genes) or citrus canker development (Xac-responsive genes), we conducted microarrays hybridization experiments at 6 and 48 hours after bacterial infiltration (habi). The analysis revealed that genes commonly modulated by Xac and Xaa are associated with basal defenses normally triggered by pathogen-associated molecular patterns, including those involved in reactive oxygen species production and lignification. Significantly, Xac-infected leaves showed considerable changes in the transcriptional profiles of defense-, cell wall-, vesicle trafficking- and cell growth-related genes between 6 and 48 habi. This is consistent with the notion that Xac suppresses host defenses near the beginning of the infection and simultaneously changes the physiological status of the host to promote cell enlargement and division. Finally, Xaa triggered a MAP kinase signaling pathway involving WRKY and ethylene-responsive transcriptional factors known to activate downstream defense genes.
Publication Title
Transcriptional analysis of the sweet orange interaction with the citrus canker pathogens Xanthomonas axonopodis pv. citri and Xanthomonas axonopodis pv. aurantifolii.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 82 Downloadable Samples
- IlluminaHiSeq2500, IlluminaGenomeAnalyzerIIx
Description
Ventricular chambers are essential for the rhythmic contraction and relaxation that occurs in every hearbeat throughout life. Congenital abnormalities in ventricular chamber formation cause severe human heart defects. How the early trabecular meshwork of myocardial fibres forms and subsequently develops into mature chambers is still poorly understood. Here we show that Notch signalling first connects chamber endocardium and myocardium to sustain trabeculation and later coordinates ventricular patterning and compaction with coronary vessel development to give rise to the mature chamber via a temporal sequence of ligand signalling determined by the glycosyltransferase Manic Fringe (Mfng). The early endocardial expression of Mfng favours Dll4-Notch1 signalling, Which induces trabeculation in the developing ventricle.Ventricular maturation and compaction in turn require Mfng and Dll4 downregulation in the endocardium, Which allows myocardial Jag1- And Jag2- Signalling to Notch1 in this tissue.Timely and spatial perturbation of this signalling equilibrium severely disrupts heart chamber formation. Our results open a new research avenue into the pathogenesis of cardiomyopathies. Overall design: Dll4 and Notch1 conditional KOs using Nfact1 and/or Tie2 driven Cre expression: RNA was isolated from pooled whole hearts of 8 (Nfact1) or 9 (Tie2) E9.5 embryos per replicate. Dll4flox;Nfatc1-Cre and WT siblings (4 KO and 4 WT replicates), Notch1flox;Nfatc1-Cre and WT siblings (3 KO and 2 WT replicates), Dll4flox;Tie2-Cre and WT siblings (3 KO and 3 WT replicates). Jag1, Jag2 and Jag1Jag2 conditional KOs using cTnT driven Cre expression: RNA was isolated from pooled heart ventricles of 4 E15.5 embryos per replicate. Jag1flox;cTnT-Cre and WT siblings (3 KO and 3 WT replicates), Jag2flox;cTnT-Cre and WT siblings (3 KO and 2 WT replicates). Jag1flox;jag2flox;cTnT-Cre and WT siblings (3 KO and 2 WT replicates). MFng Gain Of Function using Tie2 driven Cre expression: RNA was isolated from pooled heart ventricles of 4 E15.5 embryos per replicate. MFng;Tie2-Cre and WT siblings (4 GOF and 4 WT replicates). For Dll4, Noth1 and Jag1 KOs, libraries were prepared using the standard Illumina TrueSeq RNASeq library preparation kit and sequenced in a GAIIx Illumina sequencer using a 75bp single end elongation protocol. For Jag2 and Jag1Jag2 KOs and MFng GOF libraries were prepared prepared using the NEBNext Ultra RNA Library Prep Kit for Illumina and sequenced in a HiSeq2500 Illumina sequencer using a 61bp single end elongation protocol
Publication Title
Sequential Notch activation regulates ventricular chamber development.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 11 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Multipotent progenitor cells (MPs) have been observed in human kidneys and particularly in Bowman's capsule and proximal tubules. The kidney owns the ability to repair local damage and renal MPs may play a role in the regenerative processes. Microarray technology was applied to identify differentially expressed genes among resident MPs isolated from glomeruli and tubules of normal renal tissue, renal proximal tubular epithelial cells (RPTECs) and mesenchymal stem cells (MSCs).
Publication Title
TLR2 plays a role in the activation of human resident renal stem/progenitor cells.
Sample Metadata Fields
Subject
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