In embryonic stem (ES) cells. bivalent chromatin domains with overlapping repressive (H3 lysine 27 tri-methylation) and activating (H3 lysine 4 tri-methylation) histone modifications mark the promoters of more than 2. 000 genes. To gain insight into the structure and function of bivalent domains. https://www.rivervalleydanceac.com/product-category/autographed-college-photos/