Nucleosome structure and positioning play pivotal roles in gene regulation, DNA repair and other essential processes in eukaryotic cells. Nucleosomal DNA is thought to be uniformly inaccessible to DNA binding and processing factors, such as MNase. Here, we show, however, that nucleosome accessibility and sensitivity to MNase varies. Digestion of Drosophila chromatin with two distinct concentrations of MNase revealed two types of nucleosomes: sensitive and resistant. MNase-resistant nucleosome arrays are less accessible to low concentrations of MNase, whereas MNase-sensitive arrays are degraded by high concentrations. MNase-resistant nucleosomes assemble on sequences depleted of A/T and enriched in G/C containing dinucleotides. In contrast, MNase-sensitive nucleosomes form on A/T rich sequences represented by transcription start and termination sites, enhancers and DNase hypersensitive sites. Lowering of cell growth temperature to ~10°C stabilizes MNase-sensitive nucleosomes suggesting that variations in sensitivity to MNase are related to either thermal fluctuations in chromatin fiber or the activity of enzymatic machinery. In the vicinity of active genes and DNase hypersensitive sites nucleosomes are organized into synchronous, periodic arrays. These patterns are likely to be caused by “phasing” nucleosomes off a potential barrier formed by DNA-bound factors and we provide an extensive biophysical framework to explain this effect. Overall design: RNA-seq S2 cells Drosophila melanogaster
Genome-wide profiling of nucleosome sensitivity and chromatin accessibility in Drosophila melanogaster.
Specimen part, Subject
View SamplesBackgropund:In a major paradigm shift in the last decade, the knowledge about a whole class of non-coding RNAs known as miRNAs has emerged, which have proved these to be important regulators of a wide range of cellular processes by the way of modulation of gene expression. It is reported that some of these miRNAs are modified by addition or deletion of nucleotides at their ends, after biogenesis. However, the biogenesis and functions of these modifications are not well studied in eukaryotes, especially in plants. In this study, we examined the miRNA modifications in different tissues of the various plants, namely rice, tomato and Arabidopsis and identified some common features of such modifications. Results:We have analyzed different aspects of miRNA modifications in plants. To achieve this end, we developed a PERL script to find the modifications in the sequences using small RNA deep sequencing data. The modification occurs in both mature and passenger (star) strands, as well as at both the 5'' and 3'' ends of miRNAs. Interestingly, we found a position-specific nucleotide biased modification, as evident by increased number of modification at the 5'' end with the presence of Cytosine (nucleotide ''C'') at the 3’end of the miRNA sequence. The level of modifications is not strictly dependent on the abundance of miRNA. Our study showed that the modification events are independent of plant species, tissue and physiological conditions. Our analysis also indicates that the RNAi enzyme, namely, the RNA dependent RNA polymerase 6 (RDR6) may not have any role in Arabidopsis miRNA modifications. Some of these modified miRNAs are bound to AGO1, suggesting their possible roles in biological processes. Conclusions:This is a first report that reveals that 5'' nucleotide additions are preferred for mature miRNA sequences with 3’ terminal ‘C’ nucleotide. Our analysis also indicates that the miRNAs modifications involving addition of nucleotides to the 5’ or 3’ end are independent of RDR6 activity and are not restricted by plant species, physiological conditions and tissue types. The results also indicate that such modifications might be important for biological processes. Overall design: small RNA profiles of wild type and RDR6 (-) of Arabidopsis plants were generated using deep sequencing data.
3' and 5' microRNA-end post-biogenesis modifications in plant transcriptomes: Evidences from small RNA next generation sequencing data analysis.
Subject
View SamplesBACKGROUND: Dietary ABA-supplementation modulates immune and inflammatory responses in mouse models of chronic and infectious disease. However, the underlying mechanisms by which ABA elicits its immune modulatory effects are not well understood. This project used a systems approach in combination with functional and in vivo studies to investigate the target gene pathways modulated by ABA in the context of an inflammatory LPS challenge.
Abscisic acid regulates inflammation via ligand-binding domain-independent activation of peroxisome proliferator-activated receptor gamma.
No sample metadata fields
View SamplesRNA sequencing was performed to determine the uniqueness of splenic follicular IgD low B cells compared to splenic follicular IgD high and marginal zone B cells. Overall design: Splenic follicular IgD low and IgD high , and MZ B cells were sorted by FACS from naïve 8-10 weeks old mice. Total RNA was isolated from the sorted cells using RNAqueous® -4PCR kit and RNA sequencing was performed. Splenocytes from five mice were pooled for each sorting. Three independent sorting was performed for each B cell subset.
Mature IgD<sup>low/-</sup> B cells maintain tolerance by promoting regulatory T cell homeostasis.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
IDH1 mutation is sufficient to establish the glioma hypermethylator phenotype.
Specimen part
View SamplesGlioma CIMP (G-CIMP) is a powerful determinant of tumor pathogenicity but the molecular cause of G-CIMP is a fundamental question that is unresolved. Here, we show that mutation of a single gene, isocitrate dehydrogenase 1 (IDH1), directly causes the G-CIMP in gliomas by remodeling the methylome.
IDH1 mutation is sufficient to establish the glioma hypermethylator phenotype.
Specimen part
View SamplesHepatocellular carcinoma (HCC) is the fifth most-common cancer worldwide causing nearly 600,000 deaths esch year. Approximately 80% of HCC develops on the background of cirrhosis.It is necessary to identify novel genes involved in HCC to implement new diagnostic and treatment options. However, the molecular pathogenesis of HCC largely remains unsolved. Only a few genetic alterations, namely those affecting p53, -catenin and p16INK4a have been implicated at moderate frequencies of these cancers. Early detection of HCC with appropriate treatment can decrease tumor-related deaths
Genome-wide transcriptional reorganization associated with senescence-to-immortality switch during human hepatocellular carcinogenesis.
Specimen part
View SamplesCellular senescence is a tumor suppressor mechanism, and immortalization facilitates neoplastic transformation. Both mechanisms may be highly relevant to hepatocellular carcinoma (HCC) development and its molecular heterogeneity. Cellular senescence appears to play a major role in liver diseases. Chronic liver diseases are associated with progressive telomere shortening leading senescence that is observed highly in cirrhosis, but also in some HCC. We previously described the generation of immortal and senescence-programmed clones from HCC-derived Huh7 cell line.
Genome-wide transcriptional reorganization associated with senescence-to-immortality switch during human hepatocellular carcinogenesis.
Sex, Specimen part
View SamplesThe goal was to study the effects of lead exposure on gene expression and identify the lead-responsive genes. After detecting 1,536 cis-eQTLs (FDR = 10%) and 952 trans-eQTLs, we focused our analysis on Pb-sensitive “trans-eQTL hotspots”. Overall design: 158 randomly selected Drosophila Synthetic Population Resource (A2) samples (control 79 samples and Pb-treated) without replicates
Identification of Splicing Quantitative Trait Loci (sQTL) in <i>Drosophila melanogaster</i> with Developmental Lead (Pb<sup>2+</sup>) Exposure.
Cell line, Subject
View SamplesWithin the bone marrow, hematopoietic stem cells differentiate and give rise to diverse blood cell types and functions. Currently, hematopoietic progenitors are defined using surface markers combined with functional assays that are not directly linked with the in vivo potential or gene regulatory mechanisms. Here we comprehensively identify myeloid progenitor subpopulations by transcriptional sorting of single cells from the bone marrow. We describe multiple progenitor subgroups showing unexpected transcriptional priming towards seven differentiation fates, but no progenitors with a mixed state. Transcriptional differentiation is correlated with combinations of known and previously undefined transcription factors, suggesting the process is tightly regulated. Histone maps and knockout assays are consistent with the transcriptional states while traditional transplantation experiments are only partially overlapping myeloid transcriptional priming. Our analyses uncover the function of the underlying regulatory mechanisms for several sub groups and establishes a general framework for dissecting hematopoiesis. Overall design: Bone marrow Lin- cKit+ Sca1- myeloid progenitors mRNA profiles from single cells were generated by deep sequencing of thousands of single cells, sequenced in several batches in an Illumina NextSeq Please note that [1] raw data files were processed as single-ended file since second read (mate) files contain only cell/molecule barcodes and therefore, not provided. This information was appended to the fastq entry header [2] The ''experimental_design.txt'' file explains the correspondence of each single cell (WXXXX) in the ''umitab.txt'' to a sample (ABXXXX).
Transcriptional Heterogeneity and Lineage Commitment in Myeloid Progenitors.
Specimen part, Cell line, Treatment, Subject
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