Marquage nucléaire par la thymidine tritiée des dérivés de la crête neurale chez l’Amphibien Urodèle Pleurodeles waltlii Michah

Abstract

ABSTRACT Nuclear labelling by tritiated thymidine of neural crest derivatives in the amphibian Pleurodeles waltlii Nuclear labelling of the neural crest by 3H-thymidine was used to trace the migration of neural crest cells, and to study the total range of their derivatives. The main findings are: The posterior part of the neurocranium is partially derived from the cephalic neural crest. In the teeth, only the dental papilla cells and the odontoblasts are derived from the cephalic crest, but they control the formation of the adamantin organ. Cranial ganglia do not arise from the cephalic crest, but from ectodermal placodes. The anterior part of the brain and the olfactory epithelium are derived from the cephalic crest. The trunk crest is absolutely unable to produce cartilage. Schwann cells first arise from the neural crest, and later from the neural tube. Sympathetic ganglia and chromaffin cells are derived from the crest. Spinal ganglia, Rohon-Beard cells, pigment cells, mesenchyme, and part of the meninges originate from the neural crest.