Fig. 6

Anatomical differences at the venous pole at mid-cardiogenesis between mouse and human. A, B Mouse sections at E12.5 showing that the sinus venosus is connected laterally to the right- and left cardinal veins. Note that the transient left-sided SAN is still present at this stage (red arrow) and the myocardialization of the right cardinal vein is initiated. A’, B’ Human sections at 9 WGA depicting that the left superior cardinal vein has regressed. Its remnant, the ligament of Marshall (black arrow), is well discernable at this stage and shows high expression of HNK-1. Scalebars: 100 μm. AoV: aortic valve; Br: pulmonary bronchus; dAo: dorsal aorta; LA/RA: left/right atrium; LCV/RCV: left/right cardinal veins; LM: Ligament of Marshall; LV/RV: left/right ventricle; Oe: oesophagus; SAN: sinoatrial node