The generation of genome-wide maps of chromatin modification in mammalian cells is described in a paper published online by Nature. Using a technique known as single-molecule-based sequencing, Eric Lander and colleagues produced 'chromatin-state' maps that provide a rich source of information about cell state, and yield insights beyond what is typically achieved using other methods.
Although they have essentially identical genomes, the different cell types in a multicellular organism maintain markedly different behaviours that persist over extended periods. Previous research suggests that cellular state may be closely related to chromatin state - that is, modifications to histones and other proteins that package the genome. In the present study, the authors used single-molecule-based sequencing technology to construct chromatin-state maps for mouse embryonic stem cells and two other more developmentally advanced cell types, revealing the genome-wide distribution of important chromatin modifications. This allowed them to distinguish between genes that were active, poised for activation or stably repressed, reflecting cellular state and developmental potential.
The authors propose that their study provides a framework for applying comprehensive chromatin profiling towards characterizing diverse mammalian cell populations, including situations of abnormal development such as in cancer.
Eric S. Lander (Broad Institute of MIT and Harvard, Cambridge, MA, USA)
Abstract available online.
(C) Nature press release.
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