Nle inactivation induces rapid BM failure. (A) Survival curve of control and Nle^cKO (cKO) mice after Cre induction (n ≥ 13 per genotype). (B) Western blot analysis of sorted Lin⁻ and Lin⁺ BM cells and splenic cells from control or Nle^cKO mouse before and 4 or 7 d after Cre induction. Data are from one representative of three independent experiments. (C) RT-QPCR analysis of Nle mRNA expression levels in various sorted BM populations from untreated control mice (n = 3). Bars are means (SD); this experiment was performed three times. (D and E) PCR analysis on BM cells from control and Nle^cKO mice before or 5 d after Cre induction (D) and on BM and PB cells from control mice 6 or 9 mo after Cre induction (E). Similar results were obtained from at least two independent experiments. DNA obtained from Nle^Flox/Del mice was used as a control of allele amplification (lane F/Δ). (F) Spleen, thymus, and BM cellularity at different time points after Cre induction. Depicted are the means (SD) of n = 5–28 mice per genotype pooled from at least two independent experiments. (G) Representative pictures from one experiment (n = 3 per genotype) showing hematoxylin and eosin staining of transversal sections of the femur from control and Nle^cKO mice 9 d after Cre induction. Bars, 200 µm. (H) Count of various BM hematopoietic cell populations 7 d after Cre induction (n ≥ 4 per genotype, from one experiment). Bars are means (SD). *, P < 0.05; **, P < 0.005; ***, P < 0.0005.