Project description:We interrogated the genome-wide occupancy of histone modifications and RNA polymerase II at several stages of an mouse embryonic stem cell to cardiomyocyte directed differentiation protocol. These four stages represent timepoints when differentiating cultures are enriched for embryonic stem cells (ESC), mesodermal cells (MES), cardiac precursors (CP), or cardiomyocytes (CM) respectively. This study revealed many dynamic patterns of histone modifications during differentiation that are coordinated with stage-specific gene expression including a novel preactivation chromatin pattern found at genes associated with cardiac function. In addition, this study identified distal enhancer elements and enriched transcription factor motifs within enhancer regions for each stage of differentiation, which were used to predict novel transcription regulatory networks. ChIP-seq analysis of histone modifications and RNA polymerase II at 4 stages of directed cardiac differentiation of mouse embryonic stem cells. Each stage in biological duplicate or triplicate
Project description:In this study, we mapped modification of lysine 4 and lysine 27 of histone H3 genome-wide in a series of mouse embryonic stem cells (mESCs) varying in DNA methylation levels based on knock-out and reconstitution of DNA methyltransferases (DNMTs). We extend previous studies showing cross-talk between DNA methylation and histone modifications by examining a breadth of histone modifications, causal relationships, and direct effects. Our data shows a causal regulation of H3K27me3 at gene promoters as well as H3K27ac and H3K27me3 at tissue-specific enhancers. We also identify isoform differences between DNMT family members. This study provides a comprehensive resource for the study of the complex interplay between DNA methylation and histone modification landscape. Histone ChIP-seq of H3K4me3, H3K27me3, H3K4me1, and H3K27ac were performed on wild-type, Dnmt triple knock-out (Dnmt1/3a/3b; TKO), Dnmt double knock-out (Dnmt3a/3b; DKO), and respective reconstitution mouse embryonic stem cell lines
Project description:[original Title] Rapid and synchronous clearance of PcG histone modifications from Hox genes anticipates motor neuron differentiation. Hox genes are expressed in patterns that are spatially and temporally collinear with their chromosomal organization. This feature is an evolutionarily conserved hallmark of embryonic development, and in vertebrates it is critical, among others, for the specification of motor neuron subtypes and the wiring of sensory-motor circuits. We show here that the differentiation of motor neurons from stem cells is accompanied by a synchronous, domain-wide clearance of M-bM-^@M-^\repressiveM-bM-^@M-^] Polycomb (PcG)-dependent histone methylation from Hox gene chromatin domains. These findings argue against the idea, advanced recently, that the collinear dynamics of Hox gene expression invariably reflects the progressive clearance of repressive chromatin modifications. The rapid establishment of stable chromatin domains in response to a transient patterning signal likely serves as a molecular correlate of enduring rostro-caudal neural identity, which underlies the specification of postmitotic motor neuron subtype diversity and neuronal circuit assembly. The differentiation of ventral motor neurons is induced by treating embryonic stem cell cultures with retinoic acid and hedgehog agonist. Here, ChIP-chip using a custom Agilent array is used to profile the occupancy of H3K27me3, H3K4me3, and H3K79me2 at various defined stages during the differentiation process.
Project description:We interrogated the genome-wide occupancy of histone modifications and RNA polymerase II at several stages of an mouse embryonic stem cell to cardiomyocyte directed differentiation protocol. These four stages represent timepoints when differentiating cultures are enriched for embryonic stem cells (ESC), mesodermal cells (MES), cardiac precursors (CP), or cardiomyocytes (CM) respectively. This study revealed many dynamic patterns of histone modifications during differentiation that are coordinated with stage-specific gene expression including a novel preactivation chromatin pattern found at genes associated with cardiac function. In addition, this study identified distal enhancer elements and enriched transcription factor motifs within enhancer regions for each stage of differentiation, which were used to predict novel transcription regulatory networks.
