Fig. 1

Sex differences in cohesin and CTCF binding to mouse liver chromatin. a Distribution of male/female ratios for all diffReps-identified sex-differential sites that overlap a MACS2 peak for binding of cohesin (left) and CTCF (right). The y-axis shows the number of binding sites per bin, and the x-axis shows the sex difference in binding, expressed as log2(Male/Female) fold-change. Gray bars represent binding sites below the 10 read minimum count threshold, which were filtered out, and black bars represent sites that were statistically significant, but showed a |fold change| < 2 (values between -1 and 1 on the graph). Pink and blue bars, respectively, represent female-biased and male-biased sites above these thresholds. b Venn diagram indicating 137 sex-differential peaks are common between cohesin and CTCF. Overlap is based on all sex-biased peaks, including male-biased and female-biased peaks on sex chromosomes (autosomal sex-biased peak numbers are shown in parenthesis, at the right). This pattern of limited overlap was also seen when the full set of unfiltered diffReps regions was examined (Additional file 1: Figure S1E). In total, 1847 unique peaks exhibited significant sex bias in liver chromatin binding of CTCF and/or cohesin. c Heat maps and aggregate plots for four sets of sex-biased cohesin (‘Coh’) or CTCF peaks. The peak set showing significant sex bias is highlighted in red at the top of each subpanel. For the heat map, read-in-peak normalized ChIP signals are shown for male and female cohesin binding (in blue) followed by male and female CTCF binding (in purple) within a 5 kb window centered around the differential peak summit. The aggregate profiles (top) represent the average signal of the heat map below for the same 5 kb window. Within each heat map, peaks are ranked based on the magnitude of sex bias from the most sex-biased (top) to the least sex-biased (bottom)