Long-term lymphoid but not myeloid or stem cell reconstitution in X-SCID mice BM transplanted during fetal development. Twenty-four fetal (E14.5) X-SCID (CD45.2) mice were transplanted with 5 × 105 whole BM cells from congenic (CD45.1) adult donors. Eight (33%) live born transplanted mice were analyzed for reconstitution at 4, 8, and 16 weeks after birth. Contribution of donor cells to (A) total nucleated cells, (B) B cells, (C) T cells, and (D) myeloid cells as percentage of total blood cells. Data points represent individual mice; horizontal bars represent mean values of positively engrafted mice (> 0.1% for each parameter). Results are from 2 independent experiments (E). FACS analysis of donor-derived LSK cells in BM of one representative animal at 16 weeks after birth. Left panel shows typical donor and host contribution to total BM cells. Middle and right panels show donor and recipient-derived LSK cells, respectively, gated as lineage negative, and investigated for expression of the HSC markers SCA-1 and KIT. Numbers represent percentages of total BM cells (0.01%; detection level).
