pubmed:abstractText |
Increasing evidence demonstrates that stem cells maintain their identities by a unique transcription network and chromatin structure. Opposing epigenetic modifications H3K27 me3 and H3K4 me3 have been proposed to label differentiation-associated genes in stem cells, progenitor and precursor cells. In addition, many differentiation-associated genes are maintained at a poised status by recruitment of the initiative RNA Polymerase II (Pol II) at their promoter regions, in preparation for lineage-specific expression upon differentiation. Previous studies have been performed using cultured mammalian embryonic stem cells. To a lesser extent, chromatin structure has been delineated in other model organisms, such as Drosophila, to open new avenues for genetic analyses.
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