Triggering of stem cell (CFU-S) proliferation after transplantation into irradiated hosts.

The paper demonstrates the beginning of increased proliferation of the bone marrow clonogenic cells, detected by the spleen colony technique, taken from normal mice and transplanted into syngeneic recipients, lethally irradiated 24 h previously. A lag period of about 10 h preceded the beginning of increased proliferation that was determined according to the sensitivity of transplanted cells to the lethal action of hydroxyurea.