SRC-3 deficiency leads to significantly increased ROS in HSCs, and clearance of ROS can partially rescues HSC defects in SRC-3^−/−mice. (A) Relative ATP levels in MPs and LSKs from WT and SRC-3^−/− BM (n = 5 mice per group). (B-C) Flow cytometric analysis of ROS levels by (B) dichlorodihydrofluorescein diacetate (DCFH-DA) and (C) MitoSox staining in MPs, LSKs, and LT-HSCs from the BM of WT and SRC-3^−/− mice (n = 5 mice per group). (D) Schematic of NAC administration. (E-F) Flow cytometric analysis of the (E) ROS levels and (F) cell cycle of LT-HSCs from WT and SRC-3^−/− mice after NAC administration (n = 6 mice per group). (G) Schematic of NAC administration and competitive BMT. WT and SRC-3^−/− mice were injected daily with vehicle or NAC for 14 days. Then, 5 × 10⁵ BM cells (CD45.2) from these WT or SRC-3^−/− mice, together with 5 × 10⁵ competitor BM cells (CD45.1), were transplanted into lethally irradiated (10 Gy) WT (CD45.1) -recipient mice. Vehicle or NAC was provided in drinking water for 16 weeks. (H) Flow cytometric analysis of the percentages of donor-derived cells (CD45.2) in the CD45.1 recipients’ PB 16 weeks after NAC administration and competitive BMT (n = 6 mice per group). *P < .05, **P < .01. FCCP, carbonyl cyanide-4 (trifluoromethoxy) phenylhydrazone.