Project description:MacroH2As core histone variants have a unique structure that includes C-terminal nonhistone domain. MacroH2As are highly conserved in vertebrates, and are thought to regulate gene expression. However the nature of genes regulated by macroH2As and the biological significance of macroH2As for the organism remain unclear. Our gene expression studies indicate that macroH2A.1 and macroH2A.2 work together to regulate specific genes. In these studies we examine the distributions of macroH2A.1 and macroH2A.2 nucleosomes to determine if they are localized to the genes that show altered expression in macroH2A knockout mouse liver. MacroH2A.1 and macroH2A.2 nucleosomes prepared from ~ 50 fetal mouse livers were purified by thio-affinity chromatography. Five samples were sequenced: Thiopropyl Sepharose, Normal Liver - contains mononucleosomal DNA from macroH2A.1-containing nucleosomes; Activate Thiol Sepharose, Normal Liver - contains mononucleosomal DNA primarily from macroH2A.2-containing nucleosomes. Starting Material, Normal Liver - this is a reference samplefor the first two samples. It contains mononucleosomal DNA from bulk fetal liver chromatin. Activated Thiol Sepharose, Knockout Livers - this is a control sample that contains mononucleosomal DNA from non-macroH2A nucleosomes that contaminate the macroH2A.2 nucleosomes. This fraction was prepared from macroH2A1/2 double knockout fetal livers; Starting Material, Knockout Liver - this is a reference sample for the fourth sample. It contains mononucleosomal DNA from bulk chromatin prepared from macroH2A1/2 double knockout fetal livers.
Project description:MacroH2As core histone variants have a unique structure that includes C-terminal nonhistone domain. MacroH2As are highly conserved in vertebrates, and are thought to regulate gene expression. However the nature of genes regulated by macroH2As and the biological significance of macroH2As for the organism remain unclear. Here we examine macroH2A function in vivo by knocking out both macroH2A1 and macroH2A2 in the mouse. We used microarrays to examine how the absence of macroH2A.1 and macroH2A.2 histone variants affect gene expression late fetal mouse liver. Wild-type and macroH2A1/2 double knockout pre-implantation embryos were collected, mixed and implanted into wild-type recipient females. Livers were collected from the resultant fetuses at 18.5 days post coitum and snap frozen with liquid nitrogen. Total RNA was extracted from the livers using Trizol.
Project description:MacroH2As core histone variants have a unique structure that includes C-terminal nonhistone domain. MacroH2As are highly conserved in vertebrates, and are thought to regulate gene expression. However the nature of genes regulated by macroH2As and the biological significance of macroH2As for the organism remain unclear. Here we examine macroH2A function in vivo by knocking out both macroH2A1 and macroH2A2 in the mouse. We used microarrays to examine how the absence of macroH2A.1 and macroH2A.2 histone variants affect gene expression fasted adult mouse liver. Two month old male mice were fasted overnight (~16 hours). Mice were sacrificed between 9:00 and 10:00 AM, livers were collected and snap frozen with liquid nitrogen. Total RNA was extract with Trizol (life technologies) following standard protocol.
Project description:We produced a genome-wide map of the distribution of macroH2A1 histone variants in mouse liver chromatin using high-throughput sequencing of DNA from macroH2A1 nucleosomes. Although macroH2A1 nucleosomes are widely distributed across the genome, their local concentration varies over a range of 100-fold or more. The transcribed regions of most active genes are depleted of macroH2A1, with many showing depletion of 3-fold or more. The inactive X chromosome appears to have relatively uniform macroH2A1 enrichment that averages approximately 3.9-fold, but most genes that are known to escape from X inactivation do not show this enrichment. We used macroH2A1 depletion to identify additional genes that escape X inactivation, but overall, our map supports the idea that relatively few genes escape in the mouse. The map also helped identify genes that appear to be direct targets of macroH2A1-mediated repression. MacroH2A1 nucleosomes were purified from female mouse liver chromatin by thiol-affinity chromatography (Mol. Cell Biol. 26, 4410 (2006)) and their distribution was compared to that of the bulk nucleosomes used as the starting material for the purification. Nucleosomal DNA from two independent preparations was pooled and mononucleosomal DNA was prepared from both macroH2A1 and starting material nucleosomes. Each preparation used 8 to 10 livers from 8 to 10 week old female mice. For the relative macroH2A1 content file (see supplementary file), we used tools in the rna-seq workflow of Partek Genomics Suite (version 6.5b, 6.09.0806, Partek Inc.) to calculate the relative macroH2A1 content of individual genes. This program counts and normalizes hits in predefined regions specified in a refFlat file. The gene list was the Mouse build 8 version of refFlat.txt obtained from the UCSC Genome site. All exon information was stripped from the refFlat.txt file, which left only the start and stop sites for the genes. Normalized RPKM (reads per kilobase per million reads) values were compared to calculate fold change and FDR-adjusted p-values for each transcript.
Project description:Circadian profiling was performed in mouse livers from three different genotypes/treatments: Wildtype, Clock mutant, and brain-specific Clock rescue. Rescuing Clock specifically in the brain partially rescued robust circadian and harmonic rhythms. Samples were collected every 2 hours for 48 hours from 2-4 mice per time point; samples were pooled and analyzed using Affymetrix Mouse Exon arrays, analyzed at the gene level.
Project description:Western blotting (WB) is widely used to test antibody specificity, but the assay has low throughput and precision. Here we show that an inverted version of WB allows parallel readout with antibody arrays, shotgun mass spectrometry (MS) and immunoprecipitation followed by MS (IP-MS). The pipeline provides means for large-scale implementation of concepts proposed by an international working group on antibody validation (IWGAV).
Project description:HIF-2alpha is essential for (VHL-/-) ccRCC subcutaneous tumor growth in mice, and in tumor cell lines, its inhibition results in increased ROS accumulation, tumor cell death and responsiveness to radiation treatment. We have utilized transcriptional profiling to screen for putative HIF-2alpha targets genes that serve an anti-oxidant and, thus, cell survival function. A498 ccRCC cell line was treated with control siRNA or mixture of two HIF-2alpha specific siRNA for 48 hours, and RNA was harvested. 4 independent experiments were performed, and expression was compared between control and HIF-2alpha knockdown groups. 8 total samples were applied to Affymetrix Human Gene 1.0 ST Arrays. We performed two-class paired analysis using Significance Analysis of Microarrays (SAM) software to compare expression in the CT (control siRNA) and H2 (Hif2-alpha siRNA) groups.
Project description:Ars2 is a component of the nuclear cap-binding complex that is required for cellular proliferation and contributes to microRNA biogenesis. Arrays were performed to determine the repertoire of genes that change following knock-down of Ars2. Knock-down of DGCR8 was also performed to determine which changes in Ars2 knock-down cells resulted from defects in microRNA expression. 9 samples were analyzed including: three biological replicates of control siRNA-transfected HeLa cells, HeLa cells transfected with three independent siRNAs targeting Ars2, or HeLa cells transfected with three independent siRNAs targeting DGCR8.
Project description:TonEBP is a transcription factor that promotes cellular accumulation of organic osmolytes in the hypertonic renal medulla by stimulating expression of its target genes. Genetically modified animals with deficient TonEBP activity in the kidney suffer from severe medullary atrophy in association with cell death, demonstrating that TonEBP is essential for the survival of the renal medullary cells. Using both TonEBP knockout cells and RNA interference of TonEBP, we found that TonEBP promoted cellular adaptation to hypertonic stress. Microarray analyses revealed that genetic response to hypertonicity was dominated by TonEBP in that expression of totally different sets of genes was increased by hypertonicity in those cells with TonEBP vs. those without TonEBP activity. Out of over 100 potentially new TonEBP regulated genes, we selected 7 for further analyses and found that their expression was all dependent on TonEBP. RNA interference experiments showed that some of these genes – asporin, insulin-like growth factor-binding protein 5 and 7, and an extracellular lysophosphlipase D – plus Hsp70, a known TonEBP target gene, contributed to the adaptation to hypertonicity without promoting organic osmolyte accumulation. We conclude that TonEBP stimulates multiple cellular pathways for adaptation to hypertonic stress in addition to organic osmolyte accumulation. Quadruplicate samples were collected for each condition and then pooled into a single sample for hybridization to microarrays.
Project description:This SuperSeries is composed of the following subset Series: GSE34679: Effects of Ars2 or DGCR8 siRNA on gene expression GSE34680: Effects of Ars2 or DGCR8 siRNA on microRNA expression Refer to individual Series