Wif1 mice have greater numbers of stem/progenitor cells in their BM that also have more primitive in vitro clonogenic activity. (A) BM cells from Wif1 and OB mice were analyzed by 7-color flow cytometry for the expression of lineage/CD48, Sca-1, c-Kit, CD34, Flk2, and CD150 in viable cells. There are significant differences in the LSKCD48⁻ (P = .0002), lympho-myeloid multipotent progenitor; LSKCD48⁻CD34⁺Flk2⁺ (P = .0002), ST-HSC; LSKCD48⁻CD34⁺Flk2⁻ (P = .0111), and LT-HSC; LSKCD48⁻CD34⁻Flk2⁻ (P = .0447) populations. N = 6 individual mice for each strain. Significance was determined by paired 2-tailed t test (*P < .05, **P < .01). Gating strategy and a table of the data are presented in supplemental Figure 3F and supplemental Table 2. (B) Wif1 mice contain more primitive in vitro clonogenic progenitors than control OB. There are no differences in the ratio of primary Wif1 CFCs and CAFCs compared with OB controls, but secondary or LTC-CFCs and LTC-CAFCs are increased by approximately 2-fold. Data are represented as average ratio ± SD of Wif1 versus control OB from 2 to 7 HSC sorts. Significance was determined by paired 2-tailed t test: LTC-CFCs, P = .011; LTC-CAFCs, P = .009.