GSE27893
Genome-wide maps of chromatin state in early erythroid precursors versus later, more differentiated erythroblasts.
Here we globally  analyzed mRNA and epigenetic changes in both early erythroid progenitors and late erythroblasts. Concomitant with gene induction there was an increase in RNA Pol II binding and activation marks near the transcriptional start site (TSS) and the elongation mark H3K79me2 (but not H3K36me3),both near the TSS and along the full gene length. In contrast, most repressed genes became depleted of elongation marks. We also found that relative changes in histone modification levels--in particular, H3K79me2 and H4K16ac-- most predictive of gene expression patterns. Our data suggests that in terminal erythropoiesis both transcriptional initiation and elongation contribute to induction of erythroid genes; in contrast, gene repression is mainly mediated by inhibition of Pol II elongation. Our data provides a comprehensive map of the epigenome during terminal erythroid differentiation. Overall design: Examination of 7 different histone modifications and Pol II binding in 2 cell types.