Project description:Here, in order to investigate the regulation mechanism of the MSL complex in unbalanced genomes and its further functions involved in sexual dimorphism, we over-expressed MSL2 in autosomal aneuploidy (XX, AAA) and sex chromosome aneuploidy (XXX, AA), and analyzed the different transcriptomes.
Project description:Histone modifications affect DNA-templated processes ranging from transcription to genomic replication. In this study, we examine the cell cycle dynamics of the trimethylated form of histone H3 lysine 4 (H3K4me3), a mark of active chromatin that is viewed as â??long-livedâ?? [1], and that is involved in memory during cell state inheritance in metazoans [2]. We synchronized yeast using two different protocols, then followed H3K4me3 patterns as yeast passed through subsequent cell cycles. While most H3K4me3 patterns were conserved from one generation to the next, we found that methylation patterns induced by alpha factor or high temperature were erased within one cell cycle, during S phase. Early-replicating regions were erased before late-replicating regions, implicating replication in H3K4me3 loss. However, incomplete H3K4me3 erasure occurred at the majority of loci even when replication was prevented, suggesting that most erasure results from an active process. Indeed, deletion of the demethylase Jhd2 slowed erasure at most loci. Together, these results indicate overlapping roles for passive dilution and active enzymatic demethylation in erasing ancestral histone methylation states in yeast. References: [1] Ng HH, Robert F, Young RA, Struhl K (2003) Targeted recruitment of Set1 histone methylase by elongating Pol II provides a localized mark and memory of recent transcriptional activity. Mol Cell 11: 709-719. [2] Ringrose L, Paro R (2004) Epigenetic regulation of cellular memory by the Polycomb and Trithorax group proteins. Annu Rev Genet 38: 413-443. The overall design of the experiment consists of two cell cycle experiments, each consisting of the following subsets: gene expression, ChIP with anti-H3K4Me3 antibody, and ChIP input. The experiments are as follows: CCA - BY4741 bar1- cells synchronized by alpha factor arrest; CCTS - BY4741 cdc28(ts) cells synchronized by arrest at non-permissive temperature. The individual time courses are enumerated as follows: CCA gene expression (array title "Synchronized cells, xxx min, cell cycle CCA"), 18 arrays; CCA ChIP for anti-H3K4Me3 (array title "H3K4Me3 ChIP cell cycle CCA, xxx min"), 17 arrays, 1 replicate; CCA ChIP input (array title "ChIP Input cell cycle CCA, xxx min"), 18 arrays, 1 replicate; CCTS gene expression (appears in a different dataset as biological replicate "I"; array title "Synchronized cells, xxx min, biological replicate I"), 18 arrays; CCTS ChIP for anti-H3K4Me3 (array title "H3K4Me3 cell cycle CCTS, xxx min"), 2 technical replicates, 18 arrays per replicate; CCTS ChIP input (array title "ChIP Input cell cycle CCTS, xxx min"), 2 technical replicates, 18 arrays per replicate. Gene expression arrays were run against a reference of unsynchronized cells, ChIP-chip anti-H3K4Me3 samples were run against an IP (of the same epitope) of unsynchronized cells, and ChIP input samples were run against either a pool of all the time points in the time course (CCTS) or against sonicated DNA isolated from unsynchronized cells (CCA). Four additional experiments have been performed. They are referred to as series X in the title. Series 1: anti H3K4me3 CHIP time course of BY4741 bar1 delete cells (wt) synchronized with alpha factor and released in the cell cycle, 9 arrays, 1 replicate. Series 2: anti H3K4me3 CHIP time course of BY4741 bar1 jhd2 delete cells (jhd2 delete) synchronized with alpha factor and released in the cell cycle, 7 arrays, 1 replicate. Series 3: anti H3K4me3 CHIP time course of CYM36 cells (cdc7ts) synchronized with alpha factor and released in the cell cycle at the permissive 24C or at the restrictive 37C temperature, 22 arrays, 2 replicates. Series 4: anti H3K4me3 CHIP time course of BY4741 bar1 delete cells (wt) grown in galactose and synchronized with alpha factor and either released in the cell cycle in glucose media or alpha factor arrested and switched to glucose media, 6 arrays, 1 replicate.
Project description:Sarcoidosis is a disease that affects multiple organ systems, with lung disease seen commonly and is the most frequent cause of sarcoidosis-related mortality. We investigated to compare protein expression in the lung from both bronchoalveolar lavage fluid (BAL) cells and fluid (BALF) in newly diagnosed patients with sarcoidosis. Mass spectral data acquisition was conducted on an Orbitrap Fusion instrument in data-dependent mode using either label-free (BALF) or label-based (intracellular) approach. We identified 4,306 high confidence intracellular proteins (probability >99%) with 272 differentially expressed proteins controlling for an FDR 5%. The protein map to several known canonical pathways including phagosome maturation, clathrin-mediated endocytic signaling, NRF-2 mediated oxidant stress response, The examination of BALF identified 1,192 proteins, xxx and xxx protein with differential expression between controls vs. sarcoidosis and progressive vs. non-progressive sarcoidosis respectively. Several of the proteins identified mapping to the differentially expressed proteins were also detected in the BALF.
Project description:We compared the global DNA methylation levels of hairless mouse epidermis using the Infinium Mouse Methylation BeadChip from Illumina and whole genome bisulfite sequencing (WGBS). We also studied the effect of sample storage conditions by using fresh and fresh-frozen epidermis. The DNA methylation levels of xxx,xxx CpG sites covered by both the BeadChip and WGBS were compared. DNA methylation levels obtained with WGBS and the BeadChip were strongly correlated (Pearson correlation r = 0.984). We applied a threshold of 15 reads for the WGBS methylation analysis. Even at a threshold of 10 reads, we observed no substantial difference in DNA methylation levels compared with that obtained with the BeadChip. The DNA methylation levels from the fresh and the fresh-frozen samples were strongly correlated when analysed with both the BeadChip (r = 0.996) and WGBS (r = 0.994). We conclude that the two methods of analysis generally work equally well for studies of DNA methylation of mouse epidermis and find that fresh and fresh-frozen epidermis can generally be used equally well. The choice of method will depend on the specific study’s aims and the available resources in the laboratory.
Project description:Non-targeted analysis of samples derived from different mutants of M. extorquens AM1 after cultivation with Nd2O3. See publication XXX for more details.
Project description:Hexanucleotide expansion mutations in C9ORF72 are a cause of familial amyotrophic lateral sclerosis. We previously reported that long arginine-rich dipeptide repeats (DPR), mimicking abnormal proteins expressed from the hexanucleotide expansion, caused translation stalling when expressed in cell culture models. Whether this stalling provides a mechanism of pathogenicity remains to be determined. Here we explored the molecular features of the stalling and examined whether known regulatory mechanisms of ribosome quality control (RQC) are involved in efforts to sense and resolve the stalls. The most well-known RQC mechanisms come largely from studies of mRNA lacking stop codons, whereby ribosomes become stalled at the poly-adenylate sequence in the 3`UTR. Here we find that arginine-containing DPRs lead to stalling in a length dependent manner, with lengths longer than 40 repeats to invoke strong stalling. Mutational screening of 40×Gly-Xxx DPRs finds that stalling is most pronounced where Xxx are positively charged amino acids. Through a genome-wide CRISPR screen we find that genes that regulate poly-adenylate readthrough respond differently to the readthrough of arginine-rich DPRs. Indeed, we find evidence that DPR-mediated stalling has no natural regulatory responses even though the stalls may be sensed, as evidenced by an upregulation of RQC gene expression. These findings therefore implicate Arg-rich DPR-mediated stalled ribosomes as posing a particular danger to cellular health and viability. This dataset contains the RNA-sequencing data used to support the conclusions from this study.