FIG. 4.

Histological analysis of the Crk^−/− embryonic heart. Wild-type (A, C, E, and G) and Crk^−/− (B, D, F, and H) embryos at E15.5 were embedded in paraffin, and sagittal sections were obtained at a thickness of 5 μm. Sections were then stained with hematoxylin and eosin, and anatomically matching images of heart tissue were taken. The ventricles (V) in the Crk^−/− embryos were markedly dilated, and the ventricular walls (double-headed arrows) and interventricular septum (VS) were strikingly thin compared to those structures in the wild-type littermates. Panels C, D, G, and H are high-magnification images of boxes in panels A, B, E, and F, respectively. Bar, 100 μm.