Fig. 6. No signs for altered proliferation or apoptosis activity in cardiomyocytes of CAR-deficient embryos. Upper row: 2 hours before preparing of E11.5 embryos, the pregnant mother was injected with BrdU. Cryostate sections of CAR^+/+ and CAR^-/- littermate embryos were stained for incorporated BrdU (red) and counterstained for sarcomeric -actinin (blue) to mark cardiomyocytes. Micrographs show the area of the heart ventricles. For better visualization of the red staining, the lightness of the blue staining was enhanced. Bar, 100 µm. Bottom row: detection of apoptotic cells by TUNEL staining (green) of cryostate sections of E11.5 littermate embryos. Cardiomyocytes were stained for sarcomeric -actinin (red). No significant signs of apoptosis were detected independently of the genotype. Bar, 200 µm.