Control of haemopoietic stem cell proliferation by cells in DNA synthesis

It has been demonstrated that for the slowly proliferating population of the haemopoietic pluripotent stem cells (CFUs) the response after damage by hydroxyurea to cells synthesizing DNA differs from that after damage by colchicine to cells entering mitosis. The killing of DNA synthesizing cells elicits increased proliferation in the CFUs population. From this it has been inferred that cells in the S phase may inhibit the entry of nonproliferating GO cells into the cell cycle and in this way control cellular proliferation.