Project description:Pluripotent stem cells provide a powerful system to dissect the underlying molecular dynamics that regulate cell fate changes during mammalian development. Here we report the integrative analysis of genome wide binding data for 38 transcription factors with extensive epigenome and transcriptional data across the differentiation of human embryonic stem cells to the three germ layers. We describe core regulatory dynamics and show the lineage specific behavior of selected factors. In addition to the orchestrated remodeling of the chromatin landscape, we find that the binding of several transcription factors is strongly associated with specific loss of DNA methylation in one germ layer and in many cases a reciprocal gain in the other layers. Taken together, our work shows context-dependent rewiring of transcription factor binding, downstream signaling effectors, and the epigenome during human embryonic stem cell differentiation. 200 ChIP-seq experiments profiling 38 transcription factors (TFs) and several chromatin marks in 5 cell types--male human ES cell line HUES64 and directed differentiation of HUES64 towards mesendoderm (dMS, 12 hours), endoderm (dEN, 120 hours), mesoderm (dME, 120 hours), and ectoderm (dEC, 120 hours). In addition, three ES cell lines were derived with shRNA mediated knockdown of GATA4 and differention toward endoderm (dEN_shGATA4) and mesoderm (dME_shGATA4). These cell lines were used for MNChIP-seq of GATA4, SMAD1, and H3K27Ac and for 4 RRBS experiments in GATA4 knockdown and control cell lines.
Project description:Pluripotent stem cells provide a powerful system to dissect the underlying molecular dynamics that regulate cell fate changes during mammalian development. Here we report the integrative analysis of genome wide binding data for 38 transcription factors with extensive epigenome and transcriptional data across the differentiation of human embryonic stem cells to the three germ layers. We describe core regulatory dynamics and show the lineage specific behavior of selected factors. In addition to the orchestrated remodeling of the chromatin landscape, we find that the binding of several transcription factors is strongly associated with specific loss of DNA methylation in one germ layer and in many cases a reciprocal gain in the other layers. Taken together, our work shows context-dependent rewiring of transcription factor binding, downstream signaling effectors, and the epigenome during human embryonic stem cell differentiation.
Project description:Transcription factors (TFs) in concert with chromatin pathways stably reset transcriptional programs during differentiation. Yet we know little how local sites of chromatin reprogramming are specified and how the estimated 3000 TF encoded in mammalian genomes contribute to chromatin dynamics. To identify candidate TFs we developed an integrated computational approach (Epi-MARA) that models chromatin dynamics in terms of predicted transcription factor binding sites and show that it correctly predicts key TFs involved in epigenome reorganization. When applied to a time course of genome-wide H3 lysine 27 trimethylation (H3K27me3), a chromatin mark set by the Polycomb system, during neuronal differentiation of murine stem cells Epi-MARA predicted that the repressive transcription factor REST contributes to a gain of H3K27me3 at a subset of promoters during the transition from the stem to the progenitor state. To test this prediction we identified, genome-wide, the actual binding sites of REST and H3K27me3 during the differentiation in cells that are either wildtype or in which REST had been deleted. REST indeed localizes to a subset of sites that gain H3K27me3 in progenitors. Importantly, absence of REST in trans leads to a loss of H3K27me3 predominantly in the neuronal progenitor state and specifically at those regions where REST was bound. This function further requires REST binding sites in cis as their mutation leads to substantial loss of H3K27me3. Taken together we provide a novel approach to identify epigenome and TF crosstalk during cellular reprogramming and prove experimentally the prediction that REST acts as an important recruiter of Polycomb repression during early steps of neurogenesis. Dataset comprises of 15 ChIP-seq samples using chromatin from embryonic stem (ES) and neuronal progentor (NP) of wildtype and RESTko cells, which was immunoprecipitated, using antibodies against REST, H3K27me3, or Suz12
Project description:We determine the mechanisms that control global nucleosome dynamics during embryonic stem (ES) cell differentiation into endoderm. Three cell types (ES, pEHP, and EHP) were assayed for RNA expression levels.
Project description:Little is known about human segmentation clock during somitogenesis. Human embryonic stem (ES) cell differentiation towards PSM and somite cells provide a window of opportunity to probe for the dynamics of oscillatory gene expression. Using high temporal RNA-seq, we captured a transcriptional signature highly reminiscent of segmentation clock during somite differentiation. Our study provides a novel in vitro system to model human segmentation clock that is otherwise inaccessible during development.
Project description:We have determined the genome-wide binding profile of the transcription factor Sp5. Flag-tagged Sp5 was targeted to the HPRT locus in A2Lox.cre ES cells to allow for Doxycycline inducible expression. ES cells were cultured as embryoid bodies for 2 days to prime them for germ layer differentiation. Cells were then treated with Doxycycline for 24 hrs. We found that Flag-Sp5 prefentially bound to promoters associatd with several growth factor signalling pathways, but most prominently with the Wnt/beta-catenin pathway to selectively promote mesoderm differentiation over neural. These data implicate Sp5 as new regulator of Wnt/beta-catenin target expression to promotes ES cell differentation into the mesoderm lineage. Examination of Sp5 transcription factor binding in differentiating embryonic stem cells.