Cnot3 plays a critical role in cardiomyocyte proliferation in vivo. (a) Western blots to show Cnot3 protein level in developing hearts from mouse embryos at indicated time points. β-actin was used as loading control. The blots were cropped since different antibodies were incubated at the same time. (b) Western blot to show Cnot3 protein level in mouse neonatal hearts versus adult hearts. β-actin was used as loading control. The blots were cropped since different antibodies were incubated at the same time. (c) Representative images of immunofluorescence or immunochemical staining against Ki67 to show the impact of Cnot3 overexpression on cardiomyocyte proliferation in a mouse myocardial infarction model (See experimental procedures for details). DAPI (blue) was used to stain the cell nuclei. Magnification: 100x. (d) Statistical analysis of (C). Ki67+TnnT2+ cells were counted from 10 sections per mouse, 6 mice per group, values were plotted as mean ± SEM from three independent experiments, *p < 0.05. (e) Representative images of echo to show heart functions in GFP overexpression or Cnot3 overexpression hearts at indicated time points, respectively. (f) Statistical analysis of (e). Values were calculated as fractional shortening, and plotted as mean ± SEM. n = 6 per group, *p < 0.05.