Analyses of hematopoietic stem and progenitor cells. (A) Representative flow cytometric profiles of bone marrow cells with lineage-negative c-Kit⁺Sca1⁺ (LSK) hematopoietic stem cells indicated as the mean and SD of the percentage of viable cells per femur in mice at 12 months of age. The total femoral cellularity was the same for mice of all genotypes with Erg^+/+ (n = 6), Erg^+/mld2 (n = 8), Ts65Dn/Erg^+/+/+ (n = 9), and Ts65Dn/Erg^+/+/mld2 (n = 5). P values from unpaired 2-tailed t tests: P = .038 for comparison of data from Ts65Dn/Erg^+/+/+ and Ts65Dn/Erg^+/+/mld2; P = .048 for comparison of Ts65Dn/Erg^+/+/+ and Erg^+/+; and P = .57 for comparison of Ts65Dn/Erg^+/+/mld2 and Erg^+/+. (B) Hematopoietic progenitor cell numbers from agar colony assays of 25 000 bone marrow cells stimulated with stem cell factor, interleukin-3, and erythropoietin for 7 days, with mean and SD of the number of blast colonies and total colonies shown. Erg^+/+ (n = 6), Erg^+/mld2 (n = 8), Ts65Dn/Erg^+/+/+ (n = 9), and Ts65Dn/Erg^+/+/mld2 (n = 5). P values indicated are from unpaired 2-tailed t tests.