Figure 5.

The statistical helix model. The statistical helix model that we propose in this study (Equations 1 and 5) suggests that, in the absence of strong locus-specific interactions, some gene-rich domains of the mammalian chromatin tend to adopt a helix shape. This helix is averaged over the whole population of cells analyzed (5 million nuclei in each 3C sample) and thus more likely represents a statistical shape arising from the global dynamics of the chromatin than a fixed organization. It is characterized by a mean diameter 〈D〉 and mean step 〈P〉, and it thus likely corresponds with the place where the probability of finding the chromatin at a given t time is the highest (black helical curve).