Fig. 6.

Lineage tracing of mitral and aortic valves and ascending aorta. Tie2Cre-labelled endothelial cells are abundant in the mitral (a) and aortic valves (b) at E15.5. Mef2c-AHF-Cre- labelled cells make a small contribution to the mitral valve (c) are also very abundant in the aortic valve (arrow in d). Although Wnt1-Cre-expressing neural crest cells are rare contributors to the mitral valve (arrows in e), they are abundant in the aortic valve (arrow in f). g, h Mef2c-AHF-Cre and Wnt1-Cre are both abundant in the ascending aorta at E15.5, although their patterns are distinct with more the Mef2c-AHF-Cre-expressing cells in the walls of the aortic root and greater numbers of Wnt1-Cre-expressing cells found more distally