Comparison of gene deletion efficiency in Fgfr1 CKO models and testing functions of HSPCs in BM and spleen after BM damage. (A) Purified DNA and mRNA from sorted lineage positive (Lin⁺) and LSK populations in BM of Fgfr1 control and Fgfr1 CKO animals at 12 days after 5FU. PCR to detect recombined (primer a/c 300 bp) and unrecombined allay (primer b/c 400 bp). qRT-PCR detection of gene expression analysis of Fgfr1, 2, 3, 4 in LSK cells. ND = not detected. (B-E) Flow cytometric analyses of HSPCs (LT-HSC, ST-HSC, MPP) in LSK population in BM (B) and spleen (E) of Tek:Control, Tek:CKO (n = 4-6) mice 12 days after 5FU. Frequencies of total TNC shown in plots. (C-F) Comparison of absolute numbers of HSPCs (LT-HSC, ST-HSC, MPP) in BM (C) and spleen (F) from Tek:Control, Tek:CKO (n = 4-6) mice 12 days after 5FU. (D-G) Two × 10⁵ BM cells (D) or 2.5 × 10⁵ spleen cells (G) from Tek:Control, Tek:CKO mice (CD45.2) transplanted 12 days after 5FU with 2 × 10⁵ rescue BM cells (CD45.1) into lethally irradiated Ptprc recipients. PB analysis for total engrafted donor cells at 4, 8, 12 and 16 weeks posttransplantation (n = 10 per group). Error bars indicate SD (*P < .05).