[Corticotropocyte differentiation in adenohypophyseal organ cultures of chick and Japanese quail embryos].

The ability of adenohypophysis rudiment of the 4 days old chick and Japanese quail embryos for autonomous histotypical differentiation accompanied by the appearance of corticotropocytes was shown by means of multiple organ cultures and immunochemical markers. The corticotropocytes developed from the Rathke's pouch epithelium, as was shown in the experiments with recombination in culture of the adenohypophysis rudiments (Rathke's pouch) and perihypophysial mesenchyme isolated from the embryos of these two species. When cultivating the isolated fragments of adenohypophysis from 4.5 and 8 days old chick embryos, the corticotropocytes appeared in the cephalic and caudal parts of adenohypophysis. The results suggest the absence of strict cell determination in the adenohypophysis rudiment of chick embryos and that this mechanism does not play any role in providing for the regional pattern of cytodifferentiation of adenohypophysis.