The defect in pDC differentiation is cell intrinsic. (A) BM from WT (Ly5^B6; 2 × 10⁶), Ik^L/L (Ly5^B6; 5 × 10⁶), or mixtures of WT:B6.Ly5^SJL (1 × 10⁶: 1 × 10⁶) or Ik^L/L:B6.Ly5^SJL (5 × 10⁶:1 × 10⁶) were used to reconstitute lethally-irradiated B6.Ly5^SJL recipients. Recipients were analyzed 6 to 10 weeks after BM transfer. All plots are gated on small Ly5^B6+CD11c-enriched cells. Numbers indicate the percentage of gated cells in each plot. One representative experiment of 4 is shown. (B) Ikaros expression in DC subsets. WT BM and splenic pDCs (CD11c⁺ B220⁺ 120G8⁺), and splenic CD11b⁺ cDCs (CD11c⁺ CD11b⁺120G8^–) and CD8α⁺ cDCs (CD11c⁺CD8α⁺CD11b^–120G8^–) were analyzed by RT-PCR for their expression of Ikaros, Aiolos, and Helios. Whole WT thymocytes were used as a control. One representative experiment of 3 is shown.