Karen L Waldo

Learn More
We used transgenic mice in which the promoter sequence for connexin 43 linked to a lacZ reporter was expressed in neural crest but not myocardial cells to document the pattern of cardiac neural crest cells in the caudal pharyngeal arches and cardiac outflow tract. Expression of lacZ was strikingly similar to that of cardiac neural crest cells in quail-chick(More)
The primary heart tube is an endocardial tube, ensheathed by myocardial cells, that develops from bilateral primary heart fields located in the lateral plate mesoderm. Earlier mapping studies of the heart fields performed in whole embryo cultures indicate that all of the myocardium of the developed heart originates from the primary heart fields. In(More)
Double-label immunohistochemistry was used to compare early aortic arch artery development in cardiac neural crest-ablated and sham-operated quail embryos ranging from stage 13 to stage 18. The monoclonal antibody QH-1 labeled endothelial cells and their precursors, and HNK-1 labeled migrating neural crest cells. In the sham-operated embryos, the third(More)
Previous studies showed that conotruncal heart malformations can arise with the increase or decrease in alpha1 connexin function in neural crest cells. To elucidate the possible basis for the quantitative requirement for alpha1 connexin gap junctions in cardiac development, a neural crest outgrowth culture system was used to examine migration of neural(More)
Mesenchymal derivatives of the neural crest contribute to the connective tissues and blood vessels of the pharyngeal arches, and participate in the septation of the outflow tract of the heart. The present study was designed to determine the nature and timing of alterations in the development of the heart and arch arteries subsequent to diminished neural(More)
A great deal is unclear about the process of cardiac outflow septation. Much controversy exists regarding the precise details of tissue origins and movements of various components. The contribution of the cardiac neural crest to aorticopulmonary and distal truncal septation has been described; however, the distribution of the neural crest in the proximal(More)
The arterial pole of the heart is the region where the ventricular myocardium continues as the vascular smooth muscle tunics of the aorta and pulmonary trunk. It has been shown that the arterial pole myocardium derives from the secondary heart field and the smooth muscle tunic of the aorta and pulmonary trunk derives from neural crest. However, this neural(More)
It is well known that cardiac neural crest participates in development of the cardiac outflow septation and patterning of the great arteries. Less well known is that ablation of the cardiac neural crest leads to a primary myocardial dysfunction. Recent data suggests that the myocardial dysfunction occurs because of the absence of an interaction of neural(More)