Fgd5 ^mCherry-labeled HSCs have extensive self-renewal and repopulating potential. (A) Primary (1°) transplantation of 250 mCherry⁺ cells from Fgd5^mCherry/+ mice (red), or 250 control LSKCD48⁻CD150⁺-sorted HSCs (HSC^Slam) from wild-type mice (black) showing total donor reconstitution over the time course of transplantation (n = 4 recipients per group). (B) Secondary (2°; n = 3 recipients per group) and (C) tertiary (3°) transplantation (number of recipients n = 6 [Fgd5^mCherry/+] and 5 [HSC^Slam]) of whole BM cells from the 1° recipients described in A showing total donor reconstitution over the time course of transplantation. (D) Lineage breakdown of donor cells at individual recipients at 20 wk after transplant from the 3° transplants. Granulocytes (GN), macrophage/monocytes (M), B cells, and T cells are indicated by color.