The common cardinal veins in the chick embryo: their origin and development as studied by radioautographic mapping.

Abstract

AbstractThe origin of the common cardinal veins (CCVs) in the chick embryo was traced by radioautographic mapping of the movements of tritiated thymidine‐labeled grafts excised from head process to three somite stage embryos and transplanted to the endoderm‐mesoderm layer of similarly staged recipient embryos.At the head process stage the CCV cells are migrating anteriorly and laterally from the streak in the lateral plate, posterolateral to the cells which will form the pulmonary veins and aortic arches, posterior to the cells destined for the ventricular septum, and dorsal to the liver mesoderm cells. At the 15–17 somite stage, the CCV cells are in the somatic mesoderm of the lateral mesocardium, where an anastomosis between the CCVs and heart establishes channels needed for the efficient return of blood from the various embryonic venous tributaries. This investigation suggests that during the stages studied, the cells which will form the anterior portion of each CCV are positioned anterior to the cells which will form the posterior portion of each CCV.