NOD HSCs have lower cell-surface expression of Sca-1 and exhibit autonomy in vivo. (A) Bone marrow cells from NOD and B10.BR mice were harvested and stained for KSL cells. Marker 1 (M1) indicates all Sca-1 positive-staining cells. MFI of the Sca-1 staining in the c-Kit⁺/Lin^- population is indicated. Results are from one purification sort and are representative of at least 20 individual sorts per strain. (B) Engraftment B10.BR recipients conditioned with 950 cGy TBI and given 10 000 KSL cells from KSL (□), C57BL/10 (⬡), or B10.D2 (○) mice. B10.BR mice receiving no KSL cells were used as irradiation controls (dotted line). Survival B10.BR recipients of 10 000 NOD KSL cells and 30 000 NOD FCs are also shown (▪). (C) Survival of C57BL/10 recipients given NOD KSL cells alone (□) or in the presence of NOD FCs (▪). (D) Kinetics of percent donor chimerism in the peripheral blood lymphocytes (PBLs) in B10.BR recipients of NOD KSL cells alone (□) or in the presence of NOD FCs (▪). (E) B10.BR recipients were given decreasing numbers of NOD HSCs (dotted line indicates none; ○, 2000 cells; ▵, 5000; , 7500; and □, 10 000) after 950 cGy TBI. Survival of the recipients is shown based on time after transplantation. P values versus 10 000 HSCs are less than .05 and all P values versus 0 HSCs are less than .05. n.a. indicates not applicable.