Transplantation studies. (A) Schematic representation of competitive primary and secondary transplantation assays. (B) Competitive transplantation assay of 500 CD61^High and CD61^Low LT-HSCs from young mice into lethally irradiated recipients (mice per group, n = 4). Data from representative experiment are shown. (C) Competitive transplantation assay of 500 CD61^High and CD61^Low LT-HSCs from aged mice into lethally irradiated recipients (mice per group, n = 4). Data from representative experiment are shown. (D) PB chimerism levels, long term after transplantation in primary recipients of young and aged CD61^High and CD61^Low LT-HSCs. (E) Donor-derived LT-HSC frequency in the BM of primary recipients that received transplantation with aged donor CD61^High and CD61^Low LT-HSCs. (F) Secondary transplantation assay of 500 LT-HSCs derived from primary recipients that received transplantation with young CD61^High and CD61^Low LT-HSCs (mice per group, n = 4). Data from representative experiment are shown. (G) Secondary transplantation assay of 500 LT-HSCs derived from primary recipients that received transplantation with aged CD61^High and CD61^Low LT-HSCs (mice per group, n = 4). Data from representative experiment are shown. (H) PB chimerism levels, long term after transplantation in secondary recipients of young and aged CD61^High and CD61^Low LT-HSCs.