Figure 7.

Comparison of the loop length distributions of regular and disturbed chromatin fibers with experimental data from 5C experiments on a gene desert (1). The regular chromatin fibers show a completely different loop distribution because they are too stiff to have loops on small length scales. The persistence length of these fibers is 280 nm, which corresponds to a length along the contour of 13.5 kbp. One can clearly see that this is the region where the looping starts in the regular fibers. The disturbed chromatin fibers show a qualitatively similar-shaped graph compared to the 5C data. In contrast to the regular fibers, they have loops on the small scales that are very important for gene regulation.