Wnt3a deficiency leads to a severe reduction in HSC (LSK Flt3⁻) and multipotent progenitor (MPP, LSK Flt3⁺) numbers. (A) Flow cytometry analysis of LSK (Lin⁻ Sca1⁺ c-Kit⁺) population in Wt and Wnt3a^−/− FLs from E12.5 embryos. Lineage negative cells were electronically gated and analyzed for Sca1 and c-Kit expression. Percentage of Sca1⁺c-Kit⁺ cells is indicated. (B) Percentage of LSK cells in total FL is strongly decreased. Data are from 16 Wt and 11 Wnt3a^−/− FLs, belonging to 6 different litters identified by different colors. Mean values are presented as a dash. (C) Flow cytometry analysis of the Flt3 subsets in the LSK compartment. LSKs were electronically gated and analyzed for Flt3 expression. Percentages of FltL3⁻ (HSCs) and Flt3⁺ (MPPs) cells are indicated. (D) Frequency of Flt3⁻ and Flt3⁺ LSK cells in total FL. Data are from 16 Wt and 11 Wnt3a^−/− FLs, belonging to 6 different litters identified by different colors. Mean values are presented as a dash. P values are indicated in all graphs.