Figure 3. Bivalent Domain Resolution.
Resolution of a bivalent chromatin domain during neural differentiation of mouse ES cells. Chromatin state for an 18 KB region at the developmental locus encoding Otx2 (a neural specific transcription factor). In ES cells, the gene is expressed at very low levels and its promoter region is organized into chromatin that carries both H3K4 and H3K27 tri-methylation. In neural progenitors Otx2 is expressed and is associated with H3K4 tri-methylation. In embryonic fibroblasts, the gene is inactive and marked by a broad domain of H3K27 tri-methylation [11].