Neural-Inducing Activity of Newly-Mesodermalized Cells and Cellular Alterations of Induced Neurodermal Cells

In primary embryonic induction of amphibia, there are two main problems: neural-inducing activity of the organizer (chorda-mesoderm) and transformation of the presumptive ectoderm into neurodermal tissues. Many attempts to analyze the problems have been made from various points of view. It is still quite important to investigate the appearance of neural-inducing activity and cellular alterations of induced neurodermal cells. In the present paper, several results on the temporal relationship between mesodermalization and neural-inducing activity of actor cells, and on cellular alterations of induced neurodermal cells are presented.