Fig. 2

Coronal and sagittal views of the heart at E15 and E20. Ho, homozygous; He, heterozygous; WT, wild type; RA, right atrium; LA, left atrium; PA, pulmonary artery; IVS, interventricular septum; RV, right ventricle; LV, left ventricle; ASD, atrial septal defect; AO, aorta; E15, the embryo on the 15th day of embryonic period; E20, the embryo on the 20th day of embryonic period. A the He-E15 developed ASD (shown by yellow arrows). B Ho-E20 developed ASD (indicated by black arrows) combined with right atrial diverticulum (RAD, indicated by yellow pointed tips); and He-E20 developed VSD (indicated by yellow arrows) and aortic saddle (the ventricles were connected to the aorta and pulmonary artery, the left ventricle was connected to the aorta, and the aorta saddled above the ventricular septal defect, as the dashed box shown)