Female-specific association of CTCF and H3K4me2 with the macaque Xi. (a) Co-localization of CTCF (red) at the H3K4me2 'dot' (green) in the territory of the Xi in a female rhesus macaque nucleus. The white arrow indicates the Xi (top panel). The lower panel shows an independent example zoomed in. The white arrowhead points to the territory of the Xi. Nuclei are counterstained with DAPI, and the collected image converted to gray-scale to emphasize the Barr body. (b) Chromatin immunoprecipitation assessing the association of H3K4me2, H3K9me3 and CTCF with DXZ4 in male and female rhesus macaque (R. Macaque) and pig-tailed macaque (P-T. Macaque) chromatin. Samples include a no template control (Water), input DNA (Input), immunoprecipitation with the antibody indicated (IP) and non-specific rabbit serum (RS).