SOM-atlas after ES-segmentation.
a)–i) Each tile in the mosaic images is colored by the average coverage of the segments assigned to it by the respective modification. High and low coverage is depicted in red and blue, respectively (linear scale). White tiles indicate the borderlines between islands with different CEPs (see also Figure 2). De novo formation of H3K4me3 and H3K27me3 in MEFs is a frequent event (black arrows in d and e). Many of these marks remain stable in NPCs (arrows in g and h). The arrow in panel f indicates poised chromatin de novo formed in MEFs. It partially turns into repressed chromatin in NPCs by H3K9me3 modification (arrow in i). b′), e′), and h′) Subregions corresponding to the same CEP, as ES011a and ES011b, differ by their H3K27me3 status in MEF and NPC.