Fig. 7. Zonal partitioning and localization changes of major heterochromatin proteins in quiescent and proliferating cells. Schematic diagram showing the levels: negligible (white boxes), intermediate (grey boxes), and high (black boxes) of selected heterochromatin proteins in the distinct zones of the resting and activated lymphocytes and quiescent and proliferating NIH/3T3 cell nucleus. Asterisks indicate the changes associated with the transition from quiescence to proliferation.