Fig 3. Architecture of the chromosome 17 at three levels of structural hierarchy.

(A-C) Graph representation of three levels of structural hierarchy. The nodes represent partitions, the node sizes scale with partition sizes, and pie charts in nodes indicate the euchromatin/heterochromatin composition of corresponding partitions obtained from the Giemsa staining (with red denoting the centromere). The color gradient (25, 50, 75, and 100%) corresponds to heterochromatic bands with corresponding degrees of compactness. The width of edges indicates the effective interaction strength, which is obtained from the effective interaction matrices at each level of hierarchy (D-F). Partitions are labelled at each level to reflect the strict hierarchy: partition 1 contains sub-partitions 1.1 and 1.2, partition 1.2 contains sub-partitions 1.2.1, 1.2.2, 1.2.3, and 1.2.4, and so on. Weak interaction edges are omitted for clarity (see Materials and Methods for details). (G) Band representation of partitioning at the three levels of hierarchy (${\mathcal{M}}^{\left(5\right)},{\mathcal{M}}^{\left(12\right)},{\mathcal{M}}^{\left(27\right)}$). Partition boundaries observed at the lowest level persist in higher levels of hierarchy, indicating the presence of a strict hierarchy in the chromosome structural organization. To guide the eye on how the different types of chromatin packing are distributed across partitions, Giemsa staining bands are also shown on top of the partition diagrams for all levels of hierarchy.