The SAGA co-activator has been implicated in the regulation of a smal subset of genes in budding yeast in transcriptomic analyses performed in steady-state levels of RNA.
SAGA Is a General Cofactor for RNA Polymerase II Transcription.
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View SamplesHaCat cell cycle experiment: During the somatic cell cycle, DNA and epigenetic modifications in DNA and histones are copied to daughter cells. DNA replication timing is tightly regulated and linked to GC content, chromatin structure, andgene transcription, but how maintenance of histone modifications relates to replication timing and transcription is less understood.The gene expression patters on HaCaT keratinocytes during the cell cycle is studied by a time series analysis of synchroniced cells sampled at 3 hour intervals. We show that genes enriched with the repressive chromatin mark histone H3 lysine 27 tri-methylation are transcribed during DNA replication . The gene expression is related to replication timing, as genes expressed during G1/S transition andearly S phase generally have higher GC content and are replicated earlier than genes expressed during late S phase. These results indicate widespread replication-dependent expression in mammals and support a role for replication in transiently activating transcription of epigenetically silenced genes.
Transcription profiling during the cell cycle shows that a subset of Polycomb-targeted genes is upregulated during DNA replication.
Specimen part, Cell line, Time
View SamplesSingle-cell sequencing methods have emerged as powerful tools for identification of heterogeneous cell types within defined brain regions. Application of single-cell techniques to study the transcriptome of activated neurons can offer insight into molecular dynamics associated with differential neuronal responses to a given experience. Through evaluation of common whole-cell and single-nuclei RNA-sequencing (snRNA-seq) methods, here we show that snRNA-seq faithfully re-capitulates transcriptional patterns associated with experience-driven induction of activity, including immediate early genes (IEGs) such as Fos, Arc, and Egr1. SnRNA-seq of mouse dentate granule cells reveals large-scale changes in the activated neuronal transcriptome after brief novel environment exposure, including induction of MAPK pathway genes . In addition, we observe a continuum of activation states, revealing a pseudo-temporal pattern of activation from gene expression alone. In summary, snRNA-seq of activated neurons enables the examination of gene expression beyond IEGs,allowing for novel insights into neuronal activation patterns in vivo. Overall design: Examination of 1) 82 whole-cell (WC) dentate granule cells from a PTZ- or saline-treated mouse, and 2) 23 single-nuclei (SN) from dentate granule cells of a homecage (HC) mouse or 96 nuclei from a mouse exposed to a novel environment (NE)
Nuclear RNA-seq of single neurons reveals molecular signatures of activation.
Specimen part, Cell line, Treatment, Subject
View SamplesNCoR and SMRT are two paralogous vertebrate proteins that function as corepressors with unliganded nuclear receptors. Although C. elegans has a large number of nuclear receptors, orthologues of the corepressors NCoR and SMRT have not unambiguously been identified in Drosophila or C. elegans. Here, we identify GEI-8 as the closest homologue of NCoR and SMRT in C. elegans and demonstrate that GEI-8 is expressed as at least two isoforms throughout development in multiple tissues, including neurons, muscle and intestinal cells. We demonstrate that a homozygous deletion within the gei-8 coding region, which is predicted to encode a truncated protein lacking the predicted NR domain, results in severe mutant phenotypes with developmental defects, slow movement and growth, arrested gonadogenesis and defects in cholinergic neurotransmission. Whole genome expression analysis by microarrays identified sets of de-regulated genes consistent with both the observed mutant phenotypes and a role of GEI-8 in regulating transcription. Interestingly, the upregulated transcripts included a predicted mitochondrial sulfide:quinine reductase encoded by Y9C9A.16. This locus also contains non-coding, 21-U RNAs of the piRNA. Inhibition of the expression of the region coding for 21-U RNAs leads to irregular gonadogenesis in the homozygous gei-8 mutants, but not in an otherwise wild-type background, suggesting that GEI-8 may function in concert with the 21-U RNAs to regulate gonadogenesis. Our results confirm that GEI-8 is the orthologue of the vertebrate NCoR/SMRT corepressors and demonstrate important roles for this putative transcriptional corepressor in development and neuronal function.
GEI-8, a homologue of vertebrate nuclear receptor corepressor NCoR/SMRT, regulates gonad development and neuronal functions in Caenorhabditis elegans.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Sexually dimorphic genome-wide binding of retinoid X receptor alpha (RXRα) determines male-female differences in the expression of hepatic lipid processing genes in mice.
Sex, Age, Specimen part
View SamplesAnalysis of gender differential gene expression levels in mouse liver.
Sexually dimorphic genome-wide binding of retinoid X receptor alpha (RXRα) determines male-female differences in the expression of hepatic lipid processing genes in mice.
Sex, Age, Specimen part
View SamplesmRNA profiles of thousands of human tumors are available, but methods to deduce oncogenic signaling networks from these data lag behind. It is especially challenging to identify main-regulatory routes, and to generalize conclusions obtained from experimental models. We designed the bioinformatic platform R2 (http://r2.amc.nl) in parallel with a wet-lab approach of neuroblastoma. Here we demonstrate how R2 facilitates an integrated analysis of our neuroblastoma data. Analysis of the MYCN pathway suggested important regulatory connections to the polyamine synthesis route, the Notch pathway and the BMP/TGF pathway. A network of genes emerged connecting major oncogenes in neuroblastoma. Genes in the network carried strong prognostic values and were essential for tumor cell survival.
Deoxyhypusine synthase (DHPS) inhibitor GC7 induces p21/Rb-mediated inhibition of tumor cell growth and DHPS expression correlates with poor prognosis in neuroblastoma patients.
Specimen part, Cell line
View SamplesmRNA profiles of thousands of human tumors are available, but methods to deduce oncogenic signaling networks from these data lag behind. It is especially challenging to identify main-regulatory routes, and to generalize conclusions obtained from experimental models. We designed the bioinformatic platform R2 (http://r2.amc.nl) in parallel with a wet-lab approach of neuroblastoma. Here we demonstrate how R2 facilitates an integrated analysis of our neuroblastoma data. Analysis of the MYCN pathway suggested important regulatory connections to the polyamine synthesis route, the Notch pathway and the BMP/TGF pathway. A network of genes emerged connecting major oncogenes in neuroblastoma. Genes in the network carried strong prognostic values and were essential for tumor cell survival.
Deoxyhypusine synthase (DHPS) inhibitor GC7 induces p21/Rb-mediated inhibition of tumor cell growth and DHPS expression correlates with poor prognosis in neuroblastoma patients.
Specimen part, Cell line
View SamplesIn the absence of p63 expression, the epidermis fails to commit to stratification, resulting in aborted skin development. In this study, gene expression profiles of E18.5 p63 null and wt skin, were compared in an effort to identify genes that are directly or indirectly regulated by p63.
TAp63alpha induces AP-2gamma as an early event in epidermal morphogenesis.
No sample metadata fields
View SamplesNeuroblastoma is a pediatric tumor of the peripheral sympathetic nervous system with a highly variable prognosis. Activation of the PI3K/AKT pathway in neuroblastoma is correlated with poor patient prognosis, but the precise downstream effectors mediating this effect have not been determined. Here, we identify the forkhead transcription factor FOXO3a as a key target of the PI3K/AKT pathway in neuroblastoma. FOXO3a expression was elevated in low stage neuroblastoma tumors and normal embryonal neuroblasts, but reduced in late stage neuroblastoma. Inactivation of FOXO3a by AKT was essential for neuroblastoma cell survival. Treatment of neuroblastoma cells with the dual PI3K/mTOR inhibitor PI-103 activated FOXO3a and triggered apoptosis. This effect was rescued by FOXO3a silencing. Conversely, apoptosis induced by PI-103 or the AKT inhibitor MK-2206 was potentiated by FOXO3a overexpression. Further, levels of total or phosphorylated FOXO3a correlated closely with apoptotic sensitivity to MK-2206. In clinical specimens, there was an inverse relationship between gene expression signatures regulated by PI3K signaling and FOXO3a transcriptional activity. Moreover, high PI3K activity and low FOXO3a activity were each associated with an extremely poor prognosis. Our work indicates that expression of FOXO3a and its targets offer useful prognostic markers as well as biomarkers for PI3K/AKT inhibitor efficacy in neuroblastoma.
FOXO3a is a major target of inactivation by PI3K/AKT signaling in aggressive neuroblastoma.
Specimen part, Cell line, Treatment
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