Figure 3:

Intra-chromosomal interfaces between compartment domains show limited mixing. A: Density plot of the distance of all (gray line), intra-domain (blue line) and inter-domain interactions (red line, including A-A, B-B and A-B interactions). The area under the gray curve of all interactions has been adjusted so that it is double of the area under the curve of the each of the red and blue lines. B: Left panel: Comparison of A-A, B-B and A-B interactions. An expected probability of A-A, B-B and A-B interactions was calculated from all detected fragments that participate in intra-chromosomal interactions and compared to the observed proportion of interactions and converted to a base-2 logarithm. Right panel: For each number of steps, the proportion of C-walks that only contact domains of one compartment type (A or B) was calculated for experimental multi-contact data (full line) and for a set of computationally generated C-walks that was produced from sampling pairwise Hi-C data (dotted line). C: Stacked barplots with the number of compartment domains traversed by intra-chromosomal C-walks that visit 2 or more domains. These are separated by the number of steps in the C-walk on the x-axis and further separated into subplots that show C-walks that traverse both A and B domains (A-B), only A domains (A-A) and only B domains (B-B). D: Stacked barplots showing the number of intra-chromosomal C-walks that visit exactly two distinct domains (right subplot) and for intra-chromosomal walks that visit two or more distinct domains (left subplot) with 1, 2, 3, 4 and five or more inter-domain steps, separated on the x-axis by the total number of steps in a C-walk. E: Proportion of intra-domain steps in C- walks that visit two or more domains, separated on the x-axis by the total number of steps in each C-walk (solid line) compared to the same calculation done on 100 sets of permutated walks (semi-opaque dots). This was done for all the C-walks that touch two or more domains (on the left), and separately for those that visit both A and B domains (A-B), those that visit only A domains (A-A) and those that visit only B domains (B-B). F: Same as panel E but using the set of C-walks (and corresponding permutations) that visit only two compartment domains. Sum of p-values is less than 10⁻⁵. Source data are available online.