Transplanted +37kb enhancer-deleted BM cells show low chimerism and are neutropenic. (A) Transplantation scheme representing donor (CD45.2) WT, donor (CD45.2) with homozygous 1.2kb deletion, and donor (CD45.2) with homozygous 1.15kb deletion in CD45.1 recipients. Eight recipient mice per condition (n = 24) were used in the experiment. One mouse transplanted with 1.2kb enhancer-deleted BM cells died before it could be analyzed. (B) Bar chart showing percentage of CD45.1 and CD45.2 cell chimerism in PB 12 weeks after transplantation of WT and homozygous BM. (C) Flow cytometry contour plot of BM after transplantation with +37kb^WT cells: Mac1+Gr1+ myeloid cells, B220+ B cells, and CD3+ T-cell populations were gated from CD45.1 and CD45.2 fractions. (D) Proportion of +37kb^WT Mac1+Gr1+ myeloid cells, B220+ B cells, and CD3+ T-cell populations from recipient CD45.1 (up) and donor CD45.2 (lower). (E) Flow cytometry contour plots of BM after transplantation with +37kb^HOM cells: Mac1+Gr1+ myeloid cells, B220+ B cells, and CD3+ T-cell populations were gated from CD45.1 and CD45.2 fractions. (F) Proportion of +37kb^HOM Mac1+Gr1+ myeloid cells B220+ B cells and CD3+ T-cell populations from recipient CD45.1 (upper) and donor CD45.2 (lower). Experiments were conducted on PB samples of +37kb^WT (n = 8) and +37kb^HOM (n = 15), drawn 12 weeks posttransplantation.