Figure 7. Model depicting the role of neural crest in semilunar valve development.
Neural crest cells (green) are in close apposition to second heart field precursors (red) in the ventral pharynx during migration to the outflow endocardial cushions (light gray), where they provide instructive signals to orchestrate apoptosis (depicted as dark gray cells) and changes in extracellular matrix production during valve remodeling.