Author
Mridula K. Ray
Bio: Mridula K. Ray is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: Induced pluripotent stem cell & Bivalent chromatin. The author has an hindex of 1, co-authored 1 publications receiving 2431 citations.
Papers
More filters
TL;DR: It is shown that PcG proteins directly repress a large cohort of developmental regulators in murine ES cells, the expression of which would otherwise promote differentiation, and dynamic repression of developmental pathways by Polycomb complexes may be required for maintaining ES cell pluripotency and plasticity during embryonic development.
Abstract: The mechanisms by which embryonic stem (ES) cells self-renew while maintaining the ability to differentiate into virtually all adult cell types are not well understood. Polycomb group (PcG) proteins are transcriptional repressors that help to maintain cellular identity during metazoan development by epigenetic modification of chromatin structure. PcG proteins have essential roles in early embryonic development and have been implicated in ES cell pluripotency, but few of their target genes are known in mammals. Here we show that PcG proteins directly repress a large cohort of developmental regulators in murine ES cells, the expression of which would otherwise promote differentiation. Using genome-wide location analysis in murine ES cells, we found that the Polycomb repressive complexes PRC1 and PRC2 co-occupied 512 genes, many of which encode transcription factors with important roles in development. All of the co-occupied genes contained modified nucleosomes (trimethylated Lys 27 on histone H3). Consistent with a causal role in gene silencing in ES cells, PcG target genes were de-repressed in cells deficient for the PRC2 component Eed, and were preferentially activated on induction of differentiation. Our results indicate that dynamic repression of developmental pathways by Polycomb complexes may be required for maintaining ES cell pluripotency and plasticity during embryonic development.
2,549 citations
Cited by
More filters
TL;DR: High-resolution maps for the genome-wide distribution of 20 histone lysine and arginine methylations as well as histone variant H2A.Z, RNA polymerase II, and the insulator binding protein CTCF across the human genome using the Solexa 1G sequencing technology are generated.
6,488 citations
TL;DR: Recent advances in understanding how epigenetic alterations participate in the earliest stages of neoplasia, including stem/precursor cell contributions, are reviewed and the growing implications of these advances for strategies to control cancer are discussed.
4,269 citations
TL;DR: The application of single-molecule-based sequencing technology for high-throughput profiling of histone modifications in mammalian cells is reported and it is shown that chromatin state can be read in an allele-specific manner by using single nucleotide polymorphisms.
Abstract: We report the application of single-molecule-based sequencing technology for high-throughput profiling of histone modifications in mammalian cells By obtaining over four billion bases of sequence from chromatin immunoprecipitated DNA, we generated genome-wide chromatin-state maps of mouse embryonic stem cells, neural progenitor cells and embryonic fibroblasts We find that lysine 4 and lysine 27 trimethylation effectively discriminates genes that are expressed, poised for expression, or stably repressed, and therefore reflect cell state and lineage potential Lysine 36 trimethylation marks primary coding and non-coding transcripts, facilitating gene annotation Trimethylation of lysine 9 and lysine 20 is detected at satellite, telomeric and active long-terminal repeats, and can spread into proximal unique sequences Lysine 4 and lysine 9 trimethylation marks imprinting control regions Finally, we show that chromatin state can be read in an allele-specific manner by using single nucleotide polymorphisms This study provides a framework for the application of comprehensive chromatin profiling towards characterization of diverse mammalian cell populations
4,166 citations
TL;DR: The transcriptional landscape of the four human HOX loci is characterized at five base pair resolution in 11 anatomic sites and 231 HOX ncRNAs are identified that extend known transcribed regions by more than 30 kilobases, suggesting transcription of ncRNA may demarcate chromosomal domains of gene silencing at a distance.
4,003 citations
TL;DR: In this article, the ESC master transcription factors form unusual enhancer domains at most genes that control the pluripotent state, called super-enhancers, which consist of clusters of enhancers that are densely occupied by the master regulators and Mediator.
2,978 citations