Intrinsic requirement for IL-7Rα in cDC and pDC development. Lethally irradiated CD45.1/.2⁺ mice were reconstituted with an equal mixture of WT BM (CD45.1⁺) and IL-7Rα^−/− BM (CD45.2⁺) and analyzed by flow cytometry 16 weeks later. (A) Representative dot plot of CD45.1 and CD45.2 staining on CD11c⁺ cells from LNs showing the gating strategy used to identify the donor origin of DCs. (B,C) Ratio of WT versus IL-7Rα ^−/− BM-derived cells is shown for DC subsets in the pLN and skin (B) and in the spleen (C). DC and granulocyte staining was as in Figure 4B, except pDCs, which were identified as small CD11c^int GR-1⁺ CD11b⁻ cells. All pDCs expressed B220 (data not shown). All epidermal DCs were radio-resistant and of host origin (data not shown). Differences in reconstitution efficiencies between experiments were normalized by adjusting the ratio of IL-7Rα ^−/− and WT HSCs in the BM to 1. Bars represent the means ± SD for 3 to 5 mice. Data are compiled from 2 experiments. Statistical significance is calculated relative to BM HSCs (*P < .05; **P < .01).