Figure 5
Enpep is expressed in the embryonic mouse heart. (A to F) Expression of Enpep (A, D), Pitx2 (B, E) and Hcn4 (C, F) in E14.5 mouse embryos shown by in situ hybridization on two sets of consecutive sections (A to C and D to F). In addition to strong expression in the endothelial lining of the lungs, Enpep is expressed in a restricted pattern in the heart (A, D), where it is co-expressed with Pitx2 in the pulmonary veins (PV; zoom in A and B) and with Hcn4 in the leaflet of the venous valve (VV) and left superior vena cava (LSVC; zoom in A and C) as well as in the right superior vena cava (RSVC) and sinoatrial node (SAN; zoom in D and F). It is noteworthy that Enpep is not expressed in the myocardium of the left atria (LA), as is Pitx2 (zoom in B and E). AVN-His, atrial ventricular node-bundle of His; RA, right atria. Scale bars, 1 mm; close-ups, 200 μm. E, embryonic day.