Bone marrow reconstitution reveals intrinsic and nonintrinsic B-cell abnormalities. Equal numbers of flow sorted Lin^-Sca1⁺Kit⁺ hematopoietic stem cells (2000-5000 per recipient) from 6- to 10-week-old C57Bl/6-derived, Ly5.2⁺ WT mice and Fzd9^-/- or +/+ mice on the 129SvEv background (Ly5.1⁺) were used to reconstitute lethally irradiated 6- to 10-week-old Ly5.1⁺5.2⁺ recipients (C57Bl/6 derived). Analysis of peripheral blood (A) by gating on Ly5.2⁺ (WT C57Bl/6, □), Ly5.1⁺ WT (top row, ) or KO 129 (bottom row, ), or Ly5.1⁺Ly5.2⁺ (host, ○) cells and staining for B220 (B cells), CD5 (T cells), or Gr-1⁺ (myeloid cells). Percent contribution from each donor source is shown for each cell population over time (weeks). (B) Analysis of bone marrow cells 20 weeks after transplantation with percent mature (B220⁺IgM⁺) and immature (B220⁺IgM^-) B-cell progenitors derived from WT versus KO 129 donors shown. (C) Analysis of lymph node CD4⁺ or CD8⁺ T cells (CD5⁺B220^-) as in panel B. P values by paired or unpaired Student t test are as indicated by brackets. Matching symbols across different columns represent analyses from the same animal.