Project description:A large portion of the mammalian genome is associated with the nuclear lamina (NL). Here we have documented genome-wide transcriptional activities by measuring the densities, locations and orientations of transcriptionally-engaged RNA polymerase II in mouse C2C12 myoblasts using global run-on sequencing. Interestingly, a significant fraction (~20%) of NL-associated genes were detected to be transcriptionally active.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:RNA polymerase II is decreased on heat shock-induced genes when the CTD phosphatase Fcp1 is knocked down in Drosophila S2 cells. We examined transcriptionally-engaged Pol II genome-wide with GRO-seq to determine if other genes are similarly affected. Two biological replicates of nascent RNA sequencing
Project description:RNA polymerase II is decreased on heat shock-induced genes when the CTD phosphatase Fcp1 is knocked down in Drosophila S2 cells. We examined transcriptionally-engaged Pol II genome-wide with GRO-seq to determine if other genes are similarly affected.
Project description:Chromatin is highly condensed and transcriptionally repressed during mitosis. Although it is established that some general transcription factors are inactivated by phosphorylation at mitosis, many details of mitotic transcriptional repression and its underlying mechanisms are largely unknown. Here, we provide evidence that as cells enter mitosis, genes with transcriptionally engaged RNA Polymerase II (Pol II) can continue transcription until the end of the gene to clear Pol II from mitotic chromatin. Using ChIP-Seq, we find that the transcriptional reinitiation process is globally impaired in early mitosis (prophase/prometaphase), with loss of TFIIB occupancy and nucleosome-free regions at promoters. Pretreatment of nocodazole-arrested mitotic cells with the P-TEFb inhibitor flavopiridol prevents the release of promoter-proximal engaged Pol II. Global nascent RNA sequencing and RNA fluorescence in situ hybridization (FISH) of individual genes demonstrate the existence of transcriptionally engaged Pol II in early mitosis. Chemical and mutational inhibition of P-TEFb in mitosis leads to delays in the progression of cell division. Together, our study reveals a novel mechanism for mitotic transcriptional repression whereby transcriptionally engaged Pol II can progress into productive elongation and finish transcription to allow proper cellular division. ChIP-Seq of Pol II of different forms, TFIIB, H3K4me3 in human HeLa cells at different cell cycle stages. ChIP-Seq of Pol II in HeLa mitotic cells with or without CDK9 inhibitor flavopiridol pretreatment. Nascent RNA-seq in asynchronous and arrested mitotic cells.
Project description:Chromatin is highly condensed and transcriptionally repressed during mitosis. Although it is established that some general transcription factors are inactivated by phosphorylation at mitosis, many details of mitotic transcriptional repression and its underlying mechanisms are largely unknown. Here, we provide evidence that as cells enter mitosis, genes with transcriptionally engaged RNA Polymerase II (Pol II) can continue transcription until the end of the gene to clear Pol II from mitotic chromatin. Using ChIP-Seq, we find that the transcriptional reinitiation process is globally impaired in early mitosis (prophase/prometaphase), with loss of TFIIB occupancy and nucleosome-free regions at promoters. Pretreatment of nocodazole-arrested mitotic cells with the P-TEFb inhibitor flavopiridol prevents the release of promoter-proximal engaged Pol II. Global nascent RNA sequencing and RNA fluorescence in situ hybridization (FISH) of individual genes demonstrate the existence of transcriptionally engaged Pol II in early mitosis. Chemical and mutational inhibition of P-TEFb in mitosis leads to delays in the progression of cell division. Together, our study reveals a novel mechanism for mitotic transcriptional repression whereby transcriptionally engaged Pol II can progress into productive elongation and finish transcription to allow proper cellular division.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
Project description:Background: MicroRNAs (miRNAs) are a family of small, non-coding single-stranded RNA molecules involved in post-transcriptional regulation of gene expression. As such, they are believed to play a role in regulating the step-wise changes in gene expression patterns that occur during cell fate specification of multipotent stem cells. Here, we have studied whether terminal differentiation of C2C12 myoblasts is indeed controlled by lineage-specific changes in miRNA expression. Results: Using a previously generated RNA polymerase II (Pol-II) ChIP-on-chip dataset, we show differential Pol-II occupancy at the promoter regions of six miRNAs during C2C12 myogenic versus BMP2-induced osteogenic differentiation. Overexpression of one of these miRNAs, miR-378, enhances Alp activity, calcium deposition and mRNA expression of osteogenic marker genes in the presence of BMP2. Conclusions: Our results demonstrate a previously unknown role for miR-378 in promoting BMP2-induced osteogenic differentiation. Stable C2C12 cell lines C2C12-pMirn0 and C2C12-pMirn378 were generated by lentiviral transduction of C2C12 myoblasts with a Mirn378-overexpression construct and its parent vector, respectively. C2C12-pMirn0 and C2C12-pMirn378 cells were plated at 2.5 x 10^4 cells/cm2 (day -1), cultured for 1 day in DMEM 10%NCS, then (d0) treated with or without 300 ng/ml bone morphogenetic protein 2 (BMP2) for 6 days. RNA was extracted on d0, d3 and d6 and hybridized to GeneChip Mouse Genome 430 2.0 array (Affymetrix).
Project description:Quiescent C2C12 myoblasts and myoblasts that were stimulated with Angiotensin II for 12 h or 24 h Keywords = Angiotensin II Keywords: parallel sample