Fig. 7.

Model for upregulation of depletion attraction in mitotic cells. (Left) Schematic of depletion attraction in interphase live cells with soluble macromolecules in the cytoplasm (light-blue), nucleoplasm (gray), and nucleolus (dark gray). The cytoplasm, nucleus, and nucleolus are compartmentalized and not mixed during interphase. Molecular densities of the nucleoplasm are lower than the cytoplasm and nucleolus. (Right) After NEBD, soluble macromolecules that were localized to the cytoplasm, nucleus, and nucleolus at interphase are now mixed. Molecular density of chromosome milieu increases, making the depletion attraction stronger, and contributes to local condensation of chromosomes. These schematics are highly simplified models, and depletion attraction also works in interphase chromatin (smaller navy arrows).