Fig. 5

Recent BL6 tissue-shared CTCF binding is TAD-boundary associated and efficiently recruits cohesin. a Plot of the distances of CTCF binding sites to the nearest topologically associated domain (TAD) boundary reported in Bonev et al. [54] for each evolutionary type of site. The inner box focuses on the region − 50 kb and + 50 kb from the nearest TAD boundary and shows the percentage of CTCF sites from each evolutionary type at 10 kb intervals. b TAD boundaries with increasing number of associated CTCF binding tend to comprise of a cluster of both musculus-common and BL6-specific binding sites. The bar plot (top) shows the number of CTCF sites associated with each TAD boundary (i.e. within 50 kb) and in a favourable motif orientation from cortical neurons. The circles (bottom) display the evolutionary make-up of sites associated with TAD boundaries, with the number of sites per category denoted inside the circles. The size of the circles indicates the proportion of CTCF sites belonging to each of the three classes (BL6-specific only, musculus-common only and a mixture of both) at increasing number of TAD boundary-associated CTCF sites. c The percentage of all CTCF binding sites and those of different evolutionary classes for which colocalisation with a cohesin complex protein was found. The asterisks indicate the significance of a Chi-square goodness of fit test for 2 cohesin subunits colocalising with CTCF between all CTCF sites and those found to be subspecies-specific (p value = 2.8 × 10⁻⁹). The schematic diagram next to the bars is an overview of the structure of the cohesin complex