MSL (Male-specific lethal) complex increases transcription on the single X chromosome of Drosophila males in order to equalize expression of X-linked genes between males (XY) and females (XX). The increase in transcript levels correlates with MSL- dependent acetylation of histone H4 at K16 within the bodies of active genes, but identification of the transcriptional step affected has not been possible. In this study, we use global run-on sequencing (GRO-seq) to examine the specific effect of MSL complex on RNA Polymerase II (RNAP II) on a genome-wide level. Results indicate that MSL complex enhances transcription by facilitating the progression of RNAP II across the bodies of active X-linked genes. Improving transcriptional output downstream of typical gene-specific control may explain how dosage compensation can be imposed on the diverse set of genes along an entire chromosome. Overall design: Global Run-On Sequencing (GRO-Seq) reads, i.e., RNA-Seq of nascent RNA transcripts, from D. Melanogaster SL2 cells. Two biological replicates of cells treated with control GFP RNAi and cells treated with MSL2 RNAi were analyzed.
X chromosome dosage compensation via enhanced transcriptional elongation in Drosophila.
Subject
View SamplesNascent transcription profiles are shown for scaled megadomains and 100kb flanking regions before BRD4-NUT induction (0h) and at different time points (2h, 3h, 7h) following induction in 293T cells. Increase of the transcription from 0h to 7h after induction. Average level of transcriptional activity is reduced within the megadomains and their flanking regions following JQ1 treatment of TC-797 cells. Profile of nascent RNA-seq is shown for cells without JQ1 treatment, and for cells 1hr, 2.5hr and 4hr following JQ1 treatment. Overall design: Recovery and analysis of nascent RNA
The oncogenic BRD4-NUT chromatin regulator drives aberrant transcription within large topological domains.
No sample metadata fields
View SamplesThe extent of transcriptional diversity in mouse NPCs is likely to be influenced by a variety of unexamined factors that include programmed cell death, genomic mosaicism as well as a variety of “environmental” influences such as changes in exposure to signaling lipids. We therefore used scRNA-seq to assess a cohort of cortical NPCs from an embryonic mouse. We demonstrate that PAGODA (Pathway And Geneset OverDispersion Analysis) effectively recovers the known neuroanatomical and functional organization of NPCs, identifying multiple aspects of transcriptional heterogeneity within the developing mouse cortex that are difficult to discern by the existing heterogeneity analysis approaches. Overall design: Examination of mouse NPC transcriptional heterogeneity via single cell RNA-seq
Characterizing transcriptional heterogeneity through pathway and gene set overdispersion analysis.
Specimen part, Cell line, Subject
View SamplesmRNA expression levels were determined by NGS for wildtype larvae as well as for larvae lacking HP1a [Su(var)205^04/Su(var)205^05 transheterozygotes]. Overall design: RNA samples from wildtype (OR) and HP1a mutant third instar larvae were examined, using duplicate biological samples and Illumina NGS.
Enrichment of HP1a on Drosophila chromosome 4 genes creates an alternate chromatin structure critical for regulation in this heterochromatic domain.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context.
Cell line
View SamplesThe Drosophila MSL complex mediates dosage compensation by increasing transcription of the single X chromosome in males approximately two-fold. This is accomplished through recognition of the X chromosome and subsequent acetylation of histone H4K16 on X-linked genes. Initial binding to the X is thought to occur at a subset of sites. However, the consensus sequence motif of entry sites (MSL recognition element or MRE) is only slightly enriched on the X (~2 fold), and only a fraction of them is utilized by the MSL complex. Here we ask whether chromatin context could distinguish between utilized and non-utilized copies of the motif, by comparing their relative enrichment for histone modifications and chromosomal proteins mapped in the NHGRI modENCODE project. Through a comparative analysis of the chromatin features in male S2 cells, which contain MSL complex, and female Kc cells, which lack the complex, we find that the presence of active chromatin modifications, together with an elevated local GC content in surrounding sequence, has strong predictive value for functional MSL entry sites, independent of MSL binding. We tested these sites for function in Kc cells by RNAi knockdown of Sxl, resulting in induction of MSL complex. We show that ectopic MSL expression in Kc cells leads to H4K16 acetylation around these sites, and a relative increase in X chromosome transcription. Collectively, our results support a model in which a pre-existing active chromatin environment, coincident with H3K36me3, contributes to MSL entry site selection. The consequences of MSL targeting of the male X chromosome include increase in nucleosome lability, enrichment for H4K16 acetylation and JIL-1 kinase, and depletion of linker histone H1 on active X-linked genes. Our finding serves as a model to understand how chromatin and local sequence features are involved in the selection of functional protein binding sites in the genome.
Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context.
Cell line
View SamplesCells producing adrenalin are largely derived from nerve-associated Schwann cell precursors via an intermediate progenitor “bridge” cell. We demonstrate that large numbers of chromaffin cells arise from peripheral glial stem cells, termed Schwann cell precursors (SCPs) Overall design: SCPs migrate along the visceral motor nerve to the vicinity of the forming adrenal gland where they detach from the nerve and form post-synaptic neuroendocrine chromaffin cells. An intricate molecular logic drives two sequential phases of gene expression, one unique for a distinct transient cellular state and another for cell-type specification. Subsequently, these programs downregulate SCP- and upregulate chromaffin-cell-gene networks. The adrenal medulla forms through limited cell expansion and requires the recruitment of numerous SCPs. Thus, peripheral nerves serve as a stem cell niche for neuroendocrine system development.
RNA velocity of single cells.
Specimen part, Subject
View SamplesHek293 cells were metabolically labelled using 4-thiouracil as described in (Schwalb et al, Science. 2016 Jun 3;352(6290):1225-8) but without fragmentation, and then bulk RNA was prepared for sequencing using the STRT method (Islam et al, Genome Res. 2011 Jul;21(7):1160-7). Samples were incubated in duplicate for 5, 15 and 30 minutes and included an unlabeled control representing the steady-state expression state. Overall design: 2 samples each of 4 incubation times, 2 cDNA preparations, 2 tagmentation replicates, and 2 biological replicates
RNA velocity of single cells.
Cell line, Subject
View SamplesMSL (Male-specific lethal) complex increases transcription on the single X chromosome of Drosophila males in order to equalize expression of X-linked genes between males (XY) and females (XX). The increase in transcript levels correlates with MSL- dependent acetylation of histone H4 at K16 within the bodies of active genes, but identification of the transcriptional step affected has not been possible. In this study, we use global run-on sequencing (GRO-seq) to examine the specific effect of MSL complex on RNA Polymerase II (RNAP II) on a genome-wide level. Results indicate that MSL complex enhances transcription by facilitating the progression of RNAP II across the bodies of active X-linked genes. Improving transcriptional output downstream of typical gene-specific control may explain how dosage compensation can be imposed on the diverse set of genes along an entire chromosome. Overall design: Global Run-On Sequencing (GRO-Seq) reads, i.e., RNA-Seq of nascent RNA transcripts, from D. Melanogaster SL2 cells. Two biological replicates were analyzed.
Comprehensive analysis of the chromatin landscape in Drosophila melanogaster.
Subject
View SamplesThis study provides a comprehensive evaluation of changes in gene expression during treatment with Genistein in vitro.
Dose- and Time-Dependent Transcriptional Response of Ishikawa Cells Exposed to Genistein.
Treatment
View Samples