Changes of histone modification landscape in cell differentiation

During eukaryotic cell differentiation chromatin structure undergoes important changes, as manifested by extensive alterations in histone modifications. It is hypothesized that the profile of these epigenetic markers serves as a signature of the cell identity. To test this, we analyzed high-resolution genomic maps of histone methylations during differentiation of pluripotent hematopoietic stem cells into erythrocyte precursor cells. Our results indicate significant changes in both the dominant patterns of histone modifications and the genes inside the patterns after differentiation. Our results suggest that certain modifications prepare the chromatin for future activation in stem cells and their erasure results in a permanent inactivation of associated genes in differentiation-committed cells.