Wnt3a deficiency affects myeloid progenitors without impairing terminal differentiation. (A) E12.5 Wnt3a^−/− livers show decreased frequency of myeloid CD11b⁺ (Mac1) and CD11b⁺ F4/80⁻ immature subsets, accessed by flow cytometric analysis. Numbers in quadrants denote frequencies of cells gated as indicated. (B) Frequency of CD11b⁺ myeloid cells and F4/80 (+/−) subsets in total FL. Data are mean plus or minus SD of 5 Wt and 4 Wnt3a^−/− FLs, from 3 different litters. (C) Numbers of colonies yielded by Wt and Wnt3a^−/− FLs in methilcelulose colony assays. Data are mean plus or minus SD of 6 Wt and 3 Wnt3a^−/− FLs, from 3 different litters, done in triplicate. P = 3.9 × 10⁻⁴. (D) Relative frequency of the different colonies determined by morphologic analysis and confirmed by staining with May-Grunwald Giemsa. Data are representative of 4 Wt and 3 Wnt3a^−/− FLs, from 3 different litters. M, Macrophage; G, granulocyte; BFU-E, burst forming unit-erythrocyte; Mix, mixed (containing at least 3 different types of cells). (E) Erythroid colony-forming unit (CFU-E) assay of Wt and Wnt3a^−/− FLs cells. Data are mean plus or minus SD of 5 Wt and 4 Wnt3a^−/− FLs, from 3 different litters, done in triplicate. (F) Flow cytometry analysis of myeloid progenitor subsets in the FL of Wt and Wnt3a^−/− embryos. Lineage-negative cells were electronically gated and analyzed for c-Kit, Sca1 and IL-7R expression. c-Kit⁺ Sca1⁻ IL-7R⁻ cells were then analyzed for CD34 and FcγR II/III expression. Numbers next to outlined areas indicate the percentage of cells in each progenitor subset (CMP-FcγR^lo CD34⁺; GMP-FcγR^hi CD34⁺; MEP-FcγR^lo CD34⁻). (G) Frequency of CMPs, GMPs, and MEPs in total FL. The averages are indicated by a dash. Data from 11 Wt and 6 Wnt3a^−/− FLs, belonging to 6 different litters identified by different colors. P values are indicated.