Fig. 4: Deletion of Sox17 results in high-takeoff left coronary ostium.
From: A SOX17-PDGFB signaling axis regulates aortic root development
a Schematic view shows the coronary ostium position within the aortic root. Top plane indicates the sino-tubular junction between the aortic sinus and the ascending aorta. Bottom plane indicates the ventricular-aortic junction between the left ventricle and the aortic root. Dashed line a’ indicates the coronary ostia (origin of each main coronary stem in the respective aortic sinus). Dashed line b’ indicates the base of aortic valve leaflets. b, c IF images (n = 5/group) for the GFP reporter (green, indicating the lineage of Nfatc1enCre-marked aortic root endothelial cells) and for SOX17 staining (red) for aortic root and coronary arterial endothelium. Note a sharp tissue boundary (b, double arrows) between the GFP-positive/SOX17-deleted aortic root endothelium and the GFP-negative/SOX17-expressing coronary artery endothelium, which marks the coronary entries or ostia. The main coronary arteries are negative for GFP but positive for SOX17, indicating that the deletion does not affect the coronary artery endothelium. d, e Representative H&E stained continuous sections E16.5 control and Sox17eKO hearts from the base of aortic valve leaflets to the coronary ostia shows that LCO in E16.5 Sox17eKO hearts is shifted up and posteriorly toward the left coronary sinus. Arrowheads indicate the main coronary arteries and ostia. f Quantitative analysis of (d, e) confirms the high-takeoff LCO. (n = 7 for control, n = 5 for Sox17eKO, mean ± SD, unpaired two-tailed t-test, p = 0.015, *p < 0.05). g, h Representative smMHC IF images (n = 5/group) show the high-takeoff LCO (single arrow) in E16.5 Sox17eKO hearts and upshifted ventricular (smMHC-negative)-aortic (smMHC-positive) junction (double arrows). Source data are provided as a Source Data file. Scale bars: 100 µm.
