Normal function of adult HSCs after inducible deletion of Porcn in Mx1-Cre mice. (A) Normal WBCs after Cre-mediated inactivation of Porcn in MX1-Cre/Porcn^flox mice. The poly I:C–induced transient leukopenia was similar in Porcn^Del and Porcn^WT mice (3 independent experiments, P > .05, Mann-Whitney test). (B) Cre expression leads to Porcn deletion in blood samples of Mx1-Cre/Porcn^Del mice as assessed by PCR of genomic DNA (gDNA) (Del, excised Porcn allele; FL, floxed allele; WT, wild-type allele). Each lane represents an individual mouse. (C) Wnt target genes were not downregulated in peripheral blood mononuclear cells (PBMCs) from Mx1-Cre/Porcn^Del mice. Expression of Axin2 and c-Myc was normalized to PGK and HPRT (n = 5 mice in each group, P > .05, Mann-Whitney test). (D) Myeloid progenitor frequency in Mx1-Cre/Porcn^WT and Mx1-Cre/Porcn^Del did not differ significantly (n = 4 per group, 2 independent experiments). (E) LT-HSC, ST-HSC, and HPC frequency in Mx1-Cre/Porcn^WT and Mx1-Cre/Porcn^Del mice did not significantly differ (n = 4 per group, 2 independent experiments). (F) Differentiation ability of Porcn-deleted HSCs did not differ from control in colony-forming assay. Quantification of total number of colonies (colony-forming unit granulocyte-macrophage [CFU-GM], burst forming unit-erythroid [BFU-E], colony-forming unit granulocyte, erythrocyte, monocyte, megakaryocyte [CFU-GEMM]) from 3 wells in each group.