Bacteria are extremely versatile organisms which rapidly adapt to changing environments. When Escherichia coli cells switch from planktonic growth to biofilm, flagellum formation is turned off, and the production of fimbriae and extracellular polysaccharides is switched on. Here we show that BolA protein is a new bacterial transcription factor which modulates the switch from planktonic to sessile lifestyle. BolA negatively modulates flagella biosynthesis and thus swimming capacity. Furthermore, BolA overexpression favors biofilm formation and involvesinvolving fimbriae-like adhesins and curli production. Our results unraveled for the first time that BolA is a protein with high affinity to DNA, involved in the regulation of several genes of E. coli at a genome-wide scale level. Moreover, this observation further demonstrated that the most significant targets of this protein involved a complex network of genes encoding proteins extremely necessary in biofilm development processes. Herein we propose that BolA is a motile/adhesive transcriptional switch, specifically involved in the transition between the planktonic and the attachment stage of biofilm formation process.
BolA is a transcriptional switch that turns off motility and turns on biofilm development.
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View SamplesCardiac muscle differentiation in vivo is guided by sequential growth factor signals, including endoderm-derived diffusible factors, impinging on cardiogenic genes in the developing mesoderm. Previously, by RNA interference in AB2.2 mouse embryonic stem cells (mESCs), we identified the endodermal transcription factor Sox17 as essential for Mesp1 induction in primitive mesoderm and subsequent cardiac muscle differentiation. However, downstream effectors of Sox17 remained to be proven functionally. In this study, we used genome-wide profiling of Sox17-dependent genes in AB2.2 cells, RNA interference, chromatin immunoprecipitation, and luciferase reporter genes to dissect this pathway. Sox17 was required not only for Hhex (a second endodermal transcription factor) but also for Cer1, a growth factor inhibitor from endoderm that, like Hhex, controls mesoderm patterning in Xenopus toward a cardiac fate. Suppressing Hhex or Cer1 blocked cardiac myogenesis, although at a later stage than induction of Mesp1/2. Hhex was required but not sufficient for Cer1 expression. Over-expression of Sox17 induced endogenous Cer1 and sequence-specific transcription of a Cer1 reporter gene. Forced expression of Cer1 was sufficient to rescue cardiac differentiation in Hhex-deficient cells. Thus, Hhex and Cer1 are indispensable components of the Sox17 pathway for cardiopoiesis in mESCs, acting at a stage downstream from Mesp1/2.
Hhex and Cer1 mediate the Sox17 pathway for cardiac mesoderm formation in embryonic stem cells.
Cell line
View SamplesWe report a new unsupervised clustering tool for single cell RNA-seq data called SC3. We show that biologically relevant information can be obtained from preneoplastic cells of patients with myeloprolifertive disease. Overall design: examination of three different patients with myeloproloferative disease
SC3: consensus clustering of single-cell RNA-seq data.
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View SamplesStat5 is a latent transcription factor that regulates essential growth and survival functions in normal cells. Constitutive activity of Stat5 and the involvement of its C-terminally truncated variant have been implicated in blood cell malignancies and mammary or breast cancer.
Forced activation of Stat5 subjects mammary epithelial cells to DNA damage and preferential induction of the cellular response mechanism during proliferation.
Specimen part, Disease, Disease stage
View SamplesPulmonary alveoli are complex architectural units thought to undergo endogenous or pharmacologically induced programs of regeneration and degeneration. To study the molecular mechanism of alveoli loss mice were calorie restricted at different timepoints. Lungs were harvested and processed for RNA extraction.
Calorie-related rapid onset of alveolar loss, regeneration, and changes in mouse lung gene expression.
Time
View SamplesElucidating the top of the mammary epithelial cell hierarchy is highly important for understanding its regeneration capabilities and identifying target cells for transformation. Aiming for enriched mammary epithelial stem cell population, CD200highCD200R1high epithelial cells were identified. These cells represent ~50% of the mammary repopulating units (MRUs, CD49fhigh CD24med ) and termed MRUCD200/CD200R1. Gene expression of these cells was compared to all other MRU cells, termed MRUnot CD200/CD200R1, as well as individual CD200+ population (MRU-CD200R1-) and CD200R1+ population (MRU-CD200-). Overall design: Gene expression from mammary epithelial cells carrying sorted by CD200, CD200R1 markers and MRU markers. Four populations were sequenced: MRU-positive CD200 positive and CD200R1 positive; MRU-positive and not CD200 positive CD200R1 positive; not MRU CD200 positive CD200R1 negative; not MRU CD200 negative CD200R1 positive. There are 5 replicates from 5 individual mice.
High Expression of CD200 and CD200R1 Distinguishes Stem and Progenitor Cell Populations within Mammary Repopulating Units.
Sex, Specimen part, Cell line, Subject
View SamplesGiven the heterogeneity of disease evident from study of the presentation, histomorphology, disease course, and molecular lesions of bladder cancer, a cohort of 8 non-muscle invasive and 11 muscle invasive bladder cancers were profiled for gene expression using the Affymetrix HG-U133A platform.
Transcriptional signatures of Ral GTPase are associated with aggressive clinicopathologic characteristics in human cancer.
No sample metadata fields
View SamplesIt has been shown that dexamethasone (Dex) impairs the normal lung septation that occurs in the early postnatal period. Treatment with retinoic acid (ATRA) abrogates the effects of Dex. To understand the molecular basis for the Dex indiced inhibition of the formation of the alveoli and the ability of ATRA to prevent the inhibition of septation, gene expression was analyzed in 4-day old mice treated with diluent (control), Dex-treated and ATRA+Dex-treated.
DNA microarray analysis of neonatal mouse lung connects regulation of KDR with dexamethasone-induced inhibition of alveolar formation.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Muscle Expression of SOD1(G93A) Modulates microRNA and mRNA Transcription Pattern Associated with the Myelination Process in the Spinal Cord of Transgenic Mice.
Age, Specimen part
View SamplesThe lack of mouse models permitting the specific ablation of tissue-resident macrophages and monocyte-derived cells complicates understanding of their contribution to tissue integrity and to immune responses. Here we use a new model permitting diphtheria-toxin (DT)-mediated depletion of those cells and in which dendritic cells are spared. We showed that the myeloid cells of the mouse ear skin dermis are dominated by a population of melanin-laden macrophages, called melanophages, that has been missed in most previous studies. By using gene expression profiling, DT-mediated ablation and parabiosis, we determined their identity including their similarity to other skin macrophages, their origin and their dynamics. Limited information exist on the identity of the skin cells responsible for long-term tattoo persistence. Benefiting of our knowledge on melanophages, we showed that they are responsible for retaining tattoo pigment particles through a dynamic process which characterization has direct implications for improving strategies aiming at removing tattoos.
Unveiling skin macrophage dynamics explains both tattoo persistence and strenuous removal.
Specimen part, Treatment
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