Loss of lymphoid development potential in LSKs of flox/flox and Dflox/flox mice. Flow cytometric–sorted LSKs from Tam-treated mice were transplanted to recipients with helper BM cells. Donor cells (CD45.1⁻) were analyzed 8 wk after transplantation. (A) Total numbers of donor LSK, HSC, LMPP, CLP and ETP of indicated genotypes. (B) Populations of B, T, and NK cells analyzed by flow cytometry. Numbers indicate percentages of lymphocytes in total BM-nucleated cells. (C) Apoptosis in Bcl11a-deficient stem cells or progenitors (red line) analyzed by Annexin V staining. Apoptosis in these cells were rescued by p53 deficiency (green line). BM cells were harvested and stained 4 d after Tam treatment. (D and E) qRT-PCR analysis of cell cycle, lymphoid, and myeloid genes in freshly sorted HSCs. (F) qRT-PCR analysis of lymphoid and myeloid genes in LMPPs. Data represent mean values of three independent biological replicates and all values are normalized to Gapdh expression. Error bars indicate the SD. A–F represent at least three independent experiments. *, P < 0.05; **, P < 0.01.