Decreased cardiomyocyte proliferation but not increased apoptosis in the compound K51R-Tg/Nkx2.5^+/− mouse hearts.

<p>Ki67 (A–D) and TUNEL (F–I) staining was performed on 5 µm sections of mouse hearts from four genotype groups at P7 as indicated. cTnT was indicated for cardiomyocytes, and DAPI for nucleus. Statistical analyses of assays of cardiomyocyte proliferation and apoptosis were shown in E and J, respectively. The number of double positive (Ki67+/cTnT+ or TUNEL/cTnT+) cells was scored from at least three randomly selected fields in left ventricle per animal. Arrows in F–I indicated double positive (TUNEL/cTnT+) cardiomyocytes. N = 3 for each group. ***, p<0.001. Scale bar, 100 µm.