This SuperSeries is composed of the SubSeries listed below.
mRNA destabilization is the dominant effect of mammalian microRNAs by the time substantial repression ensues.
Sex, Age, Specimen part, Cell line, Treatment, Time
View SamplesThe RNA-directed DNA methylation (RdDM) pathway in plants controls gene expression via cytosine DNA methylation. The ability to manipulate RdDM would shed light on the mechanisms and applications of DNA methylation to control gene expression. Here, we identified diverse RdDM proteins that are capable of targeting methylation and silencing in Arabidopsis when tethered to an artificial zinc finger (ZF-RdDM). We studied their order of action within the RdDM pathway by testing their ability to target methylation in different mutants. We also evaluated ectopic siRNA biogenesis, RNA Polymerase V (Pol V) recruitment, targeted DNA methylation, and gene expression changes at thousands of ZF-RdDM targets. We found that co-targeting both arms of the RdDM pathway, siRNA biogenesis and Pol V recruitment, dramatically enhanced targeted methylation. This work defines how RdDM components establish DNA methylation, and enables new strategies for epigenetic gene regulation via targeted DNA methylation. Overall design: 40 RNA-seq
Co-targeting RNA Polymerases IV and V Promotes Efficient De Novo DNA Methylation in Arabidopsis.
Specimen part, Subject
View SamplesMicroRNAs (miRNAs) regulate target mRNAs through a combination of translational repression and mRNA destabilization, with mRNA destabilization dominating at steady state in the few contexts examined globally. Here, we extend the global steady-state measurements to many additional mammalian contexts and find that regardless of the miRNA, cell type, growth condition or translational state, mRNA destabilization explains most (70% to >90%) miRNA-mediated repression. We also determine the relative dynamics of translational repression and mRNA destabilization for endogenous mRNAs as a miRNA is induced. Although translational repression occurs rapidly, its effect on gene expression is relatively weak, such that by the time consequential repression ensues, the effect of mRNA destabilization dominates. These results add to the fundamental understanding of miRNAs, imply that consequential miRNA-mediated repression is largely irreversible and simplify future studies, dramatically extending the known contexts and time points for which monitoring mRNA changes captures most of the direct miRNA effects.
mRNA destabilization is the dominant effect of mammalian microRNAs by the time substantial repression ensues.
Sex, Age, Specimen part
View SamplesThe weekly turnover of the intestinal epithelium is driven by multipotent, Lgr5+, crypt base columnar cells (CBCs). In response to injury, however, Lgr5+ cells are lost but then re-emerge and are required for successful recovery. How these resurgent Lgr5+ stem cells arise is unclear. We transcriptionally profiled single cells from regenerating intestinal epithelia and identified a unique cell type we term the revival stem cell (rSC). rSCs are mutually exclusive to CBCs and are distinguished by elevated expression of cell survival and DNA repair genes. In homeostasis, rSCs are extremely rare, but nevertheless give rise to all the major cell types of the intestine including crypt-villus axes. After damage rSCs display a 20-fold, Yap-dependent, transient expansion, reconstitute the Lgr5+ CBC compartment and are required to regenerate a functional intestine. These studies define a unique stem cell phenotype that is mobilized by damage to reconstitute the intestinal epithelium. Overall design: Examination of regenerating mouse intestinal epithelium.
Single-cell transcriptomes of the regenerating intestine reveal a revival stem cell.
Specimen part, Cell line, Treatment, Subject
View SamplesNitric oxide being a versatile molecule inside biological systems, from being both a cell signaling molecule to a potent stress agent, has significant effect in the transcriptional response in fission yeast.
Global transcriptomic profiling of Schizosaccharomyces pombe in response to nitrosative stress.
No sample metadata fields
View SamplesSound vibration (SV) causes various developmental and physiological changes in plants. It strongly suggests the existence of sophisticated molecular mechanisms for SV perception and signaling in plants. However, the underlying molecular mechanism of SV-mediated plant responses remains elusive. Herein, we investigated the transcript changes in Arabidopsis thaliana upon five different single frequencies of SV treatment.
Plant acoustics: in the search of a sound mechanism for sound signaling in plants.
Age, Specimen part
View Samplesidentification of differentially expressed genes in gas6 homozygous mutant hindbrain when compared to wildtype hindbrain in zebrafish Overall design: Total RNA was extracted from dissected hindbrain of gas6 homzygous mutants and wildtype embryos at 48hpf using the RNeasy Mini Kit (Qiagen). Three libraries from wildtype embryos and three libraries from gas6 mutants were then generated from 3mg RNA using the TruSeq Stranded mRNA Library Prep Kit (Illumina). All libraries were analyzed for quality on a bioanalyzer prior to sequencing (Agilent 2100 BioAnalyzer).
Analysis of novel caudal hindbrain genes reveals different regulatory logic for gene expression in rhombomere 4 versus 5/6 in embryonic zebrafish.
Specimen part, Subject
View SamplesHepatic stellate cells (HSCs) are the primary cell type responsible for liver fibrosis, the final common pathway leading to cirrhosis and liver failure for nearly every cause of chronic liver disease. Activation of HSCs in response to injury represents the key step in hepatic fibrogenesis, and is characterized by a phenotypic change from a non-fibrogenic, quiescent HSC to a fibrogenic HSC myofibroblast that secretes extracellular matrix proteins responsible for the fibrotic scar. We developed a small molecule screen to identify compounds that revert fibrotic human HSC myofibroblasts to an inactive phenotype through the quantification of lipid droplets with fluorescent microscopy. Conditions were optimized in a 384-well format using culture in Matrigel as a positive control. We screened 1600 compounds and identified 30 small molecules that induce reversion to an inactive phenotype. Among the hits, we identified five tricyclic antidepressants (TCAs) and showed that this class of drugs also repressed ACTA2 and COL1A1 while promoting PPAR-gamma expression. RNA sequencing analysis implicated extracellular matrix proteins and the sphingolipid pathway as a target of the TCAs. Overall design: HSCs and HSCs stimulated with TGF-beta were treated with the TCA, nortriptyline or ethanol vehicle for 48 hours. RNA-seq was performed in duplicate for each condition
Tricyclic Antidepressants Promote Ceramide Accumulation to Regulate Collagen Production in Human Hepatic Stellate Cells.
No sample metadata fields
View SamplesDiscriminating pathogenic bacteria from energy-harvesting commensals is key to host immunity. Using mutants defective in the enzymes of O-linked N-acetylglucosamine (O-GlcNAc) cycling, we examined the role of this nutrient-sensing pathway in the Caenorhabidits elegans innate immune response. Using whole genome transcriptional profiling, O-GlcNAc cycling mutants exhibited deregulation of unique stress- and immune-responsive genes as well as genes shared with the p38 MAPK/PMK-1 pathway. Moreover, genetic analysis showed that deletion of O-GlcNAc transferase (ogt-1) yielded animals hypersensitive to the human pathogen S. aureus but not to P. aeruginosa. Genetic interaction studies further revealed that nutrient-responsive OGT-1 acts through the conserved -catenin (BAR-1) pathway and in concert with p38 MAPK/PMK-1 to modulate the immune response to S. aureus. The participation of the nutrient sensor O-GlcNAc transferase in an immunity module conserved from C. elegans to humans reveals an unexplored nexus between nutrient availability and a pathogen-specific immune response.
Conserved nutrient sensor O-GlcNAc transferase is integral to C. elegans pathogen-specific immunity.
Treatment
View SamplesEscherichia coli exhibits diauxic growth in sugar mixtures due to CRP-mediated catabolite repression and inducer exclusion related to phosphotransferase system enzyme activity. Replacement of the native crp gene with a catabolite repression mutant (referred to as crp*) alleviates diauxic effects in E. coli and enables co-utilization of glucose and other sugars. While previous studies have examined the effects of expressing CRP* mutants on the expression of specific catabolic genes, little is known about the global transcriptional effects of CRP* expression.
Transcriptional effects of CRP* expression in Escherichia coli.
No sample metadata fields
View Samples