Fig. 4

Contribution of YFP⁺ cardiomyocytes to heart homeostasis. a-c Immunofluorescence of freshly-isolated CM from Bmi1-YFP mice TM-induced at six to eight weeks of age, throughout mouse lifetime at days (5d), 2 months (2m), 6 months (6m) and 12 months (12m) post-TM induction. SαA in red (a), anti-YFP staining in green (b) and CM at higher magnification (c); DAPI, blue. Bars in (a), (b), 1,000 μm; (c), 200 μm. d LacZ⁺ CM in adult Bmi1-LacZ mice 5 days (n = 4), 2m (n = 2) and 6m (n = 2) post-TM induction. Bars, 200 μm. Data shown as mean ± SEM. YFP yellow fluorescent protein, CM cardiomyocytes, TM tamoxifen, SαA sarcomeric α-actinin