Autoradiographic Study of the Developing Chick Embryo Esophagus

Abstract

Autoradiography was employed to examine the incorporation pattern of 3H-thymidine and 3H-uridine into presumptive stratified squamous epithelial cells and prospective degenerating cells of the chick embryo esophagus. The incorporation pattern of 3Hthymidine suggests that esophageal epithelial nuclei in the vesiculated region undergo interkinetic migration, synthesizing DNA at the basement membrane and moving to the free surface of the vesicles to complete the mitotic phase of the cell cycle. Incorporation patterns in prospective degenerating cells show a cessation of DNA synthesis correlating with the posterior-to-anterior degeneration gradient. No regionally specific pattern of 3H-uridine incorporation was observed.