Fig. 3

Fig. 3. itga3b mutant embryos exhibit impaired cardiomyocyte proliferation. (A) Immunostaining of MEF2 (green) or PCNA (red) in ventricles and atria of sibling wild-type (WT, a), itga3b^+/- (b) and itga3b^−/− (c) mutants at 96 hpf. Significantly decreased cardiomyocyte numbers (d) and percentages of MEF2⁺PCNA⁺ cardiomyocytes (e) were detected in ventricles and atria of itga3b^+/- and itga3b^−/− mutants compared to sibling wild-types. Total number of embryos examined is indicated within each bar. Error bars indicate s.e.m. Quantitative data were analyzed by ANOVA with Tukey's multiple comparisons. Treatments that are not significantly different (α = 0.05) from each other are labeled with the same letter. Comparisons of ventricular cardiomyocyte numbers between sib WT and itag3b^+/- or itga3b^−/− had p < 0.0001 and comparisons of atrial cardiomyocyte numbers between sib WT and itag3b^+/- or itga3b^−/− had p = 0.0085 and p < 0.0001, respectively (d). Comparisons of MEF2⁺PCNA⁺ cardiomyocytes between sib WT and itag3b^+/- or itga3b^−/− in ventricles or atria had p < 0.0001 (e). (B) Similar low levels of apoptotic cells in ventricular cardiomyocytes labeled with MEF2 (green) were detected by the TUNEL assay (red) in sibling wild-types, itga3b^+/- and itga3b^−/− mutants at 96 hpf. Scale bar, 100 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)