Cell cycle analysis of histone marks and 4C in human Fucci ESCs

Using the Fucci cell cycle indicator system in hESCs, we evaluated the patterns of bivalent histone marks and enhancer histone marks during the cell cycle by ChIP-seq. We further evaluated how the chromatin architecture changed during the cell cycle. We found that bivalent domains are cell cycle regulated, and H3K4me3 specifically peaks during the late G1 stage of the cell cycle. H3K27me3, however, is largely unchanged during the cell cycle. Cell cycle-regulated bivalent domains interact with enhancers and form cell cycle regulated chromatin interactions.