H4K20 trimethylation (H4K20me3) at the X centromere in two human cell lines and one of the mouse-human somatic cell hybrids.

<p>Each number across the schematic representation of the centromere is a genomic site that was interrogated by ChIP-PCR. Control regions, including GAPDH, AFM and X-linked ZXDA are also included. The bar graph shows relative enrichment for H3K27 methylation (n = 3 with SD) calculated as percentage of input.