Gene rearrangements in pDCs from different sources. RAG1⁺ CMPs, RAG1 CMPs, or CLPs were cultured with congenic CD45.1⁺ total BM feeder cells and FL. Progenitor-derived pDCs were identified as CD45.1⁻CD45.2⁺CD11c⁺BST-2⁺ after 5 days. pDCs were analyzed by PCR for the presence of D-J rearrangements at their IgH locus. (A) More frequent result of no detectable rearrangement in pDCs from CMPs. (B) Occasional result of Ig gene D-J rearrangements in pDCs from CMPs.