Decreased short-term radioprotective ability of whole bone marrow despite preserved homing of HSCs from STAT5A/5B-deficient mice.

(A) Irradiated recipients received either 2.5 × 10⁵STAT5A/5B^+/+ whole bone marrow cells (n = 6), 2.5 × 10⁵ STAT5A/5B^−/− whole bone marrow cells (n = 8), or no donor cells (n = 3). Survival rates are shown as a Kaplan-Meyer plot. (B) Irradiated recipients received 5 × 10⁶ CFSE-labeled whole bone marrow cells from a STAT5A/5B^+/+ donor (n = 3) or a STAT5A/5B^−/− donor (n = 3). Bone marrow was harvested 23 hours after transplantation, and the absolute number of CFSE⁺ cells within the HSC (lin^dim/Sca-1⁺) gate per mouse was determined.