The pDCs in bone marrow are slowly replenished. (A) Purified B220⁺CD19^-CD11c^Lo pDCs were stained with 7AAD for analysis of DNA content. (B) Mice were injected and then fed BrdU in their drinking water for the indicated intervals when cells were isolated and evaluated by flow cytometry. Enriched B220⁺CD19^-CD11c^Lo pDCs (□) were compared with B220⁺CD19⁺ B-lineage lymphocytes (○).