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GSE23711
Saccharomyces cerevisiae
6 Downloadable Samples
Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
The basic unit of genome packaging is the nucleosome, and nucleosomes have long been proposed to restrict DNA accessibility both to damage and to transcription. However, nucleosome number in cells was considered fixed, and no condition was described where nucleosome number was reduced. We show here that mammalian cells lacking High Mobility Group Box 1 protein (HMGB1) contain a reduced amount of core, linker and variant histones, and a correspondingly reduced number of nucleosomes. Yeast nhp6 mutants lacking NHP6A and B proteins, which are related to HMGB1, also have a reduced amount of histones and fewer nucleosomes. Nucleosome limitation in both mammalian and yeast cells increases the sensitivity of DNA to damage, increases transcription globally, and the relative expression of about 10% of genes. In yeast nhp6 cells the loss of more than one nucleosome in four does not affect the location of nucleosomes and their spacing, but nucleosomal occupancy. The decrease in nucleosomal occupancy is non-uniform, and our results can be modelled assuming that different nucleosomal sites compete for the available histones: sites with high affinity are almost always packaged into nucleosomes both in wt and nucleosome-depleted cells, whereas sites with low affinity are less frequently packaged in nucleosome-depleted cells. We suggest that by modulating the occupancy of nucleosomes histone availability may constitute a novel layer of epigenetic regulation.
Publication Title
Substantial histone reduction modulates genomewide nucleosomal occupancy and global transcriptional output.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The non-coding Xist RNA triggers silencing of one of the two female X chromosomes during X inactivation in mammals. Gene silencing by Xist is restricted to special developmental contexts found in cells of the early embryo and specific hematopoietic precursors. The absence of critical silencing factors might explain why Xist cannot silence outside these contexts. Here, we show that Xist can also initiate silencing in a lymphoma model. Using the tumor context we identify the special AT rich binding protein SATB1 as an essential silencing factor. We show that loss of SATB1 in tumor cells abrogates the silencing function of Xist. In normal female lymphocytes Xist localizes along SATB1 filaments and, importantly, forced Xist expression can relocalize SATB1 into the Xist cluster. This reciprocal influence on localization suggests a molecular interaction between Xist and SATB1. SATB1 and its close homologue SATB2 are expressed during the initiation window for X inactivation in embryonic stem cells and are recruited to surround the Xist cluster. Furthermore, ectopic expression SATB1 or SATB2 enables gene silencing by Xist in embryonic fibroblasts, which normally do not provide an initiation context. Thus, SATB1 functions as a crucial initiation factor and may act to organize genes for silencing by Xist during the initiation of X inactivation.
Publication Title
SATB1 defines the developmental context for gene silencing by Xist in lymphoma and embryonic cells.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus, Homo sapiens
- 5 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302), Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Hypomethylation of the IL17RC promoter associates with age-related macular degeneration.
Sample Metadata Fields
Age, Specimen part, Disease, Cell line
View Samples- Homo sapiens
- 4 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Age related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly population worldwide. While recent studies have demonstrated strong genetic associations of single nucleotide polymorphisms within a number of genes and AMD, other modes of regulation are also likely to play a role in its aetiology. We undertook DNA methylation microarray analysis on monozygotic and dizygotic twins who were discordant for AMD and identified methylated IL17RC promoters as being present only in non-AMD control individuals rather than in AMD patients. We validated this finding of a significantly decreased level of methylation on the IL17RC promoter in AMD siblings as well as in a case control study involving 202 genetically unrelated AMD patients and 96 controls (95% CI, 0.03-0.17, P=3.1x10-8). Further, we showed that hypomethylation of the IL17RC promoter in AMD patients led to an elevated expression of its protein and mRNA in peripheral blood as well as in the retina and choroid, suggesting that the DNA methylation pattern and expression of IL17RC may potentially serve as a biomarker for the diagnosis of AMD and likely plays a role in disease pathogenesis.
Publication Title
Hypomethylation of the IL17RC promoter associates with age-related macular degeneration.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 1 Downloadable Sample
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Background
Publication Title
Hypomethylation of the IL17RC promoter associates with age-related macular degeneration.
Sample Metadata Fields
Age, Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Skeletal muscle microRNA and messenger RNA profiling in cofilin-2 deficient mice reveals cell cycle dysregulation hindering muscle regeneration.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
mRNA Expression in Quadriceps Muscle from Cofilin-2 Null Mice Compared to WT Littermates on Day 7
Publication Title
Skeletal muscle microRNA and messenger RNA profiling in cofilin-2 deficient mice reveals cell cycle dysregulation hindering muscle regeneration.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Dendritic cells (DCs) are major antigen-presenting cells that play a key role in initiating and regulating innate and adaptive immune responses. DCs are critical mediators of tolerance and immunity. The functional properties of DCs changes with age.
Publication Title
Alterations in gene array patterns in dendritic cells from aged humans.
Sample Metadata Fields
Age, Specimen part, Subject
View Samples- Homo sapiens
- 35 Downloadable Samples
IlluminaHiSeq2000
Description
Background: Personalized medicine is predicated on the notion that individual biochemical and genomic profiles are relatively constant in times of good health and to some extent predictive of disease or therapeutic response. We report a pilot study quantifying gene expression and methylation profile consistency over time, addressing the reasons for individual uniqueness, and its relation to N=1 phenotypes. Methods: Whole blood samples from 4 African American women, 4 Caucasian women, and 4 Caucasian men drawn from the Atlanta Center for Health Discovery and Well Being study at three successive 6-month intervals were profiled by RNASeq, miRNASeq, and Illumina Methyl-450 arrays. Standard regression approaches were used to evaluate the proportion of variance for each type of omic measure that is among individuals, and to quantify correlations among measures and with clinical attributes related to wellness. Results: Longitudinal omic profiles are in general highly consistent over time, with an average of 67% of the variance in transcript abundance, 42% of CpG methylation level (but 88% for the most differentiated CpG per gene), and 50% of miRNA abundance among individuals, which are all comparable to 74% of the variance among individuals for 74 clinical traits. One third of the variance can be attributed to differential blood cell type abundance, which is also fairly stable over time, and a lesser amount to eQTL effects, whereas seven conserved axes of covariance that capture diverse aspects of immune function explain over half of the variance. These axes also explain a considerable proportion of individually extreme transcript abundance, namely approximately 100 genes that are significantly up- or down-regulated in each person and are in some cases enriched for relevant gene activities that plausibly associate with clinical attributes. A similar fraction of genes have individually divergent methylation levels, but these do not overlap with the transcripts, and fewer than 20% of genes have significantly correlated methylation and gene expression. Conclusions: People express an “omic personality” consisting of peripheral blood transcriptional and epigenetic profiles that are constant over the course of a year and reflect various types of immune activity. Baseline genomic profiles can provide a window into the molecular basis of traits that might be useful for explaining medical conditions or guiding personalized health decisions. Overall design: Whole blood samples from 12 subjects drawn from the Atlanta Center for Health Discovery and Well Being study at three successive 6-month intervals were profiled by RNASeq, miRNASeq, and Illumina Methyl-450 arrays.
Publication Title
Omic personality: implications of stable transcript and methylation profiles for personalized medicine.
Sample Metadata Fields
No sample metadata fields
View Samples- Rattus norvegicus
- 10 Downloadable Samples
- Illumina HiSeq 2500
Description
To investigate the effects of TBI on affecting the gene expressions in the hippocampus of male SD rats by RNA-Seq.. Overall design: Male Sprague–Dawley (SD) rats weighing between 200 and 240 g were housed in cages and maintained in environmentally-controlled rooms (22–24C) with a 12-h light/dark cycle. After acclimatization for 1 week on standard rat chow, the rats were subjected to TBI by fluid percussion injury (FPI) or sham surgery. At 1 week post-surgery the rats were tested for learning abilities, and then were sacrificed by decapitation. The fresh tissues including the hippocampus were dissected out, flash frozen, and stored at -70°C for later transcriptome and DNA methylome sequencing experiments. All experiments were performed in accordance with the United States National Institutes of Health Guide for the Care and Use of Laboratory Animals and were approved by the University of California at Los Angeles Chancellor’s Animal Research Committee.
Publication Title
Traumatic Brain Injury Induces Genome-Wide Transcriptomic, Methylomic, and Network Perturbations in Brain and Blood Predicting Neurological Disorders.
Sample Metadata Fields
No sample metadata fields
View Samples