Fig. 3. Family 26 with persistent truncus arteriosus and craniofacial anomalies. (A) A pup that died at birth had a short snout, low set ears, rounded head, and short neck. (B) A normal neonatal C57BL6/J pup. Alcian blue staining (E,F) showed the abnormal pup (E) had a shortened premaxilla (PM), maxilla (M) and nasal bone (N), while its frontal bone (F) was expanded. The shape of the mandible (MN) was also altered. The heart exhibited persistent truncus arteriosus (PTA in D), when compared with normal septated outflows (C), consisting of an aortic (Ao) and pulmonary (P) trunk. Histological sections of the abnormal heart (G,H) revealed a single outflow positioned over the RV and VSD. This vessel gave rise to the ascending aorta (AAo) with its brachiocephalic artery (BCA), the right and left pulmonary arteries (RPA, LPA), and the coronary arteries (LCA, RCA). A VSD with inlet extension can be seen in (H). Asterisk in H denotes abnormal AV valve. Panels A and B, E and F, and G and H are shown at the same magnification.