Necdin deficiency does not affect cell-cycle status of HSCs under homeostatic conditions. (A) Normal numbers of KSL cells in the BM of young Ndn^+m/−p mice. c-Kit⁺ Sca-1⁺ cells in the Lin⁻ fraction (KSL cells) were detected by flow cytometry. Data are shown as mean absolute number ± SD (n = 11). (B-C) Normal numbers of CD34^−/low KSL in the BM of young and old Ndn^+m/−p mice. c-Kit⁺ Sca-1⁺ cells in the Lin⁻ CD34^−/low fraction (CD34^−/low KSL cells) of young (10-12 weeks) and old (18 months) mice were determined by flow cytometry. Data are shown as mean absolute number ± SD (young: n = 11, old: n = 3). (D) Normal frequency of quiescent CD34^−/low KSL cells in Ndn^+m/−p mice. BM cells from Ndn^+/+ and Ndn^+m/−p mice were stained with Pyronin Y, anti-CD34, c-Kit, Sca-1, and lineage markers. (Top panels) Representative pattern of 5 independent experiments. (Bottom panel) Data are shown as mean percentages ± SD of Pyronin Y^low CD34^−/low KSL cells (n = 5). (E-F) Normal BrdU incorporation in Ndn^+m/−p HSCs. BrdU (1 mg/mL) was administered orally to Ndn^+/+ and Ndn^+m/−p mice for 7 days, and BrdU incorporation in CD34^−/low and CD34⁺ KSL cells was evaluated using anti-BrdU antibodies. (E) Representative pattern of BrdU⁺ CD34^−/low KSL cells. (F) Data shown are the mean percentages ± SD of BrdU⁺ cells in the CD34^−/low KSL (top panel) or CD34⁺ KSL cells (bottom panel). Ndn^+/+: n = 5; Ndn^+m/−p: n = 4.