Fig. 3. LR defects in the visceral organs of Foxh1^c/- mice. Visceral organs and heart sections of wildtype (WT) and Foxh1^c/- neonates are shown. Genotype is indicated at the top of each column. (A,B) Lobation of the lung. In the wild-type mouse (A), the left and right lungs have one and four lobes, respectively. In most Foxh1^c/- mice (B), both left and right lungs have four lobes. AL, accessory lobe; CaL, caudal lobe; CrL, cranial lobe; ML, medial lobe; H, heart; LL, left lobe. (C,D) The azygos vein (az) of the wild-type mouse is located on the left side (C). In most Foxh1^c/- mice, the azygos vein is located on the right side (D) or both sides. ao, aorta. (E,F) Hypoplasia of the spleen (sp) in the Foxh1^c/- mouse (F). st, stomach. (G,H) Visceral organs including the stomach are reversed in many Foxh1^c/- mice (H). du, duodenum; li, liver. (I-K) The heart apex is located on the left side of the wild-type mouse (I), but is either in the middle (J) or on the right side (K) of Foxh1^c/- mice. la, left atrium; lv, left ventricle; ra, right atrium; rv, right ventricle. (L,M) The right renal vein is located anteriorly to the left renal vein in the wild-type mouse (L). In Foxh1^c/- mice, the relative positions of left and right renal veins are reversed or the two veins are located at the same level (M). cvc, caudal vena cava; ki, kidney; rv, renal vein; aa, abdominal aorta. (N) Aberrant positioning of the portal vein (po) in the Foxh1^c/- mouse. (O-T) Frontal sections of the heart. In most Foxh1^c/- mice, the heart manifests severe malformations, including transposition of the great arteries (P,S) and double outlet of the right ventricle (Q,T). pa, pulmonary artery.