The Role of Neural Crest Cells in Vertebrate Cardiac Outflow Development
Throughout vertebrate evolution, the cardiac outflow vasculature has changed from a branchial arch system to a systemic and pulmonary circulatory system. However, all vertebrate hearts and outflow tracts still develop from a single heart tube. In the chick and mouse, cardiac neural crest cells divide the single outflow tract into the aorta and pulmonary arteries. Additionally, cardiac neural crest cells provide the smooth muscle of the aortic arch arteries, help to remodel the aortic arch arteries into asymmetrical structures, and contribute cardiac ganglia. I review the major contributions of cardiac neural crest cells to the outflow vasculature of the chick and mouse and apply this information to study cardiac neural crest cell contributions to vertebrates that lack a divided circulatory system. I re-evaluate the role of cardiac neural crest cells in zebrafish vasculature and find that these cells do contribute to the gill arch arteries, the ventral aorta and cardiac ganglia, but they do not contribute to myocardium. I also study the outflow tract development of the turtle Trachemys scripta to understand the process of outflow septation in a vertebrate that has a divided outflow tract but an incomplete division of the ventricle. I compare the chick outflow tract to the turtle. The formation of the proximal versus distal cushions and the appearance of smooth muscle cells within the distal cushions of the turtle are very similar to the cushion position and cell types within the cushions of the chick. In the chick, the smooth muscle positive cells in the distal cushions are derived from cardiac neural crest cells. I hypothesize that cardiac neural crest cells are also responsible for the outflow tract septation of reptiles. These results demonstrate that the pattern of cardiac neural crest cell contribution to vertebrate vasculature remains predictable and consistent, enabling future studies to focus on changes in vascular patterning caused by cardiac neural crest cells among different vertebrate lineages.
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.
Rights for Collection: Duke Dissertations