(A) Co-immunostaining of FOXC2 (green) with ZBTB16 (red) in seminiferous tubules of the adult testes at day 20 post busulfan treatment. Scale bar, 50 μm. (B) ZBTB16+, GFRA1+, and FOXC2+ population dynamics after busulfan treatment (20 mg/kg, n=10). (C) Co-immunostaining of FOXC2 (green) with MKI67 (red) in seminiferous tubules of the adult testes at day 20 post busulfan treatment. Scale bar, 50 μm. (D) MKI67+FOXC2+ proportions in relation to the whole FOXC2+ population at different time points after busulfan treatment (n=4). (E) Schematic illustration for lineage tracing of FOXC2+ cell after busulfan treatment. (F) Lineage tracing of the GFP+ cells at day 20 and month 2 after busulfan treatment (scale bar, 50 μm). (G) The testes (scale bar, 1 mm), seminiferous tubules, and epididymis (scale bar, 50 μm) at months 4, 7, and 12 post TAM induction and busulfan injection. m, month. (H, I) The proportion dynamics of GFP patches (H) and GFP+ progenies (I). Values, mean ± s.e.m. (n=10). w, week; m, month.