Project description:mRNA Expression in Quadriceps Muscle from Cofilin-2 Null Mice Compared to WT Littermates on Day 7 Quadriceps muscle resected on day 7 from cofilin-2 deficient mice and wildtype littermates were collected and mRNA was isolated. Expression changes were analyzed by microarray.
Project description:Ten-eleven translocation (Tet) family of DNA dioxygenases converts 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5- carboxylcytosine (5caC) through iterative oxidation reactions. While 5mC and 5hmC are relatively abundant, 5fC and 5caC are at very low levels in the mammalian genome. Thymine DNA glycosylase (TDG) and base excision repair (BER) pathways can actively remove 5fC/5caC to regenerate unmethylated cytosine, but it is unclear to what extent and at which part of the genome such active demethylation processes take place. Here, we have performed high-throughput sequencing analysis of 5mC/5hmC/5fC/5caC- enriched DNA using modification-specific antibodies and generated genome-wide distribution maps of these cytosine modifications in wild-type and Tdg-deficient mouse embryonic stem cells (ESCs). We observe that the steady state 5fC and 5caC are preferentially detected at repetitive sequences in wild-type mouse ESCs. Depletion of TDG causes marked accumulation of 5fC and 5caC at a large number of distal gene regulatory elements and transcriptionally repressed/poised gene promoters, suggesting that Tet/TDG-dependent dynamic cycling of 5mC oxidation states may be involved in regulating the function of these regions. Thus, comprehensive mapping of 5mC oxidation and BER pathway activity in the mammalian genome provides a promising approach for better understanding of biological roles of DNA methylation and demethylation dynamics in development and diseases. Gene expression comparison of control and Tdg knockdown mouse embryonic stem cells.
Project description:Ten-eleven translocation (Tet) family of DNA dioxygenases converts 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5- carboxylcytosine (5caC) through iterative oxidation reactions. While 5mC and 5hmC are relatively abundant, 5fC and 5caC are at very low levels in the mammalian genome. Thymine DNA glycosylase (TDG) and base excision repair (BER) pathways can actively remove 5fC/5caC to regenerate unmethylated cytosine, but it is unclear to what extent and at which part of the genome such active demethylation processes take place. Here, we have performed high-throughput sequencing analysis of 5mC/5hmC/5fC/5caC- enriched DNA using modification-specific antibodies and generated genome-wide distribution maps of these cytosine modifications in wild-type and Tdg-deficient mouse embryonic stem cells (ESCs). We observe that the steady state 5fC and 5caC are preferentially detected at repetitive sequences in wild-type mouse ESCs. Depletion of TDG causes marked accumulation of 5fC and 5caC at a large number of distal gene regulatory elements and transcriptionally repressed/poised gene promoters, suggesting that Tet/TDG-dependent dynamic cycling of 5mC oxidation states may be involved in regulating the function of these regions. Thus, comprehensive mapping of 5mC oxidation and BER pathway activity in the mammalian genome provides a promising approach for better understanding of biological roles of DNA methylation and demethylation dynamics in development and diseases. Refer to individual Series
Project description:Polycomb group (PcG) proteins play important roles in repressing lineage-specific genes and maintaining the undifferentiated state of mouse embryonic stem cells (mESCs). However, the mechanisms by which PcG proteins are recruited to their targets are largely unknown. Here, we show that the histone demethylase Kdm2b is highly expressed in mESCs and regulated by the pluripotent factors Oct4/Sox2 directly. Depletion of Kdm2b in mESCs causes de-repression of lineage-specific genes and induces early differentiation. The function of Kdm2b depends on its CXXC-ZF domain, which mediates Kdm2b’s genome-wide binding to CpG islands (CGIs). Kdm2b interacts with the core components of the Polycomb repressive complex 1 (PRC1) and recruits the complex to the CGIs of early lineage-specific genes. Thus, our study not only reveals a novel Oct4/Sox2-Kdm2b-PRC1-CGI regulatory axis and its function in maintaining undifferentiated state of mESCs, but also demonstrates a critical function of Kdm2b in recruiting PRC1 to the CGIs of lineage-specific genes to repress their expression. In this dataset, we include the expression data for control and Kdm2b knockdown mouse embryonic stem cells. We analyzed the gene expression in control and Kdm2b knockdown mouse embryonic stem cells using the Affymetrix MoGene-1_0-st-v1 platform.
Project description:Investigation of expression differences between melanomas harvested from MiniCoopR-GFP versus MiniCoopR-SETDB1 transgenic zebrafish The embryos described in this study are further analyzed in a manuscript submitted for publication by White, et al. A 12 chip study comparing gene expression levels in 80hpf animals either WT (Tu), mitf-BRAFV600E, p53-/-, or mitf-BRAFV600E;p53-/- (double)
Project description:In this study, we subjected the phenomenon of fractional killing in a clonal population of TRAIL-sensitive cells to careful analysis. We asked whether cells that survive initial exposure to TRAIL are sensitive or resistant to subsequent treatment with TRAIL or other apoptosis-inducing agents. We observed that TRAIL survivor cells were highly resistant to a subsequent treatment with TRAIL 24hr later but that this resistance disappeared following several days in culture. Resistance did not involve downregulation of TRAIL receptors and extended to death ligands that bind different classes of receptors: TRAIL survivors were transiently resistant to FasL and vice versa. Gene expression analysis revealed that NF-kB-mediated inflammatory genes were activated in transiently resistant survivor cells leading to an inflammatory phenotype, but resistance was mediated by an independent mechanism related to changes in signaling at the DISC. Periodic exposure to TRAIL sustained resistance, demonstrating a component of induced survival signaling leading to transient acquired resistance to TRAIL. Based on these results we propose that TRAIL treatment leads to a transient adaptation in survivor cells that can be sustained in cells exposed to long-term TRAIL treatments, leading to acquired resistance. Minimizing the impact of cell-to-cell variability on TRAIL-mediated killing will thus require appropriate spacing of stimuli as well as the use of additional agents that inhibit pro-survival pathways. RNA was collected from Control (untreated) MCF10A cells, Survivors of TRAIL treatment (Day 1), Reset cells (survivors on Day 7), and Repeat cells (Survivors treated with TRAIL on 2 subsequent days). RNA was also collected from Control and Survivor MCF10A cells expressing an IKB-super-repressor construct (Addgene, Plasmid 15291; Boehm et al., 2007), or treated with caspase inhibitors. Three biological experiments were performed (on different days) with 1-2 replicates of each sample collected for each experiment. The total number of samples was 31, on 4 IlluminaRef8 BeadChips (one sample was from an unrelated experiment and was not included). The number of total replicates for each treatment is as follows: Control (7); Survivors (6); Reset (3); Repeat (3); Control-IKB-super-repressor (2); Survivors-IKB-super-repressor (2); Control-zVADinhibitor (2); Survivors-zVADinhibitor (2); Control-IETDinhibitor (2); Survivors-IETDinhibitor (2).
Project description:Identification of genes differentially regulated after treatment of zebrafish embryos from 50% epiboly to 24hpf with 6.5uM leflunomide A six chip study comparing expression levels of zebrafish embryos treated with leflunomide 6.5uM
Project description:Many pathways regulating blood formation have been elucidated, yet how each coordinates with embryonic biophysiology to modulate the spatio-temporal production of hematopoietic stem cells (HSCs) is currently unresolved. Here, we report that glucose metabolism impacts the onset and magnitude of HSC induction in vivo. In zebrafish, transient elevations in physiological glucose levels elicited dose-dependent effects on HSC development, including enhanced runx1 expression and hematopoietic cluster formation in the Aorta-Gonad-Mesonephros (AGM) region; embryonic-to-adult transplantation studies confirmed glucose increased functional HSCs. Glucose uptake was required to mediate the enhancement in HSC development; likewise, metabolic inhibitors diminished nascent HSC production and reversed glucose-mediated effects on HSCs. Increased glucose metabolism preferentially impacted hematopoietic and vascular targets, as determined by gene expression analysis, through mitochondrial-derived reactive oxygen species (ROS)-mediated stimulation of hypoxia inducible factor 1α (hif1α); epistasis assays demonstrated hif1α regulates HSC formation in vivo and mediates the dose-dependent effects of glucose metabolism on the timing and magnitude of HSC production. We propose this fundamental metabolic-sensing mechanism enables the embryo to respond to changes in environmental energy input and adjust hematopoietic output to maintain embryonic growth and ensure viability. We performed microarray analysis to explore the changes in gene expression that occur in repsonse to altered metabolism during the induction of developmental hematopoeisis. We compared RNA from zebrafish raised in a solution of 1% glucose from 12-36hpf vs controls. Two biological replicates for each condition were performed.
Project description:Investigation of expression differences between skin and melanomas from a transgenic BRAFV600E zebrafish model of melanoma The embryos described in this study are further analyzed in a manuscript submitted for publication by White, et al. A 15 chip study using RNA extracted from either WT zebrafish skin, mitf-BRAFV600E;p53-/- skin or mitf-BRAFV600E;p53-/- melanoma