Neural crest and early fore limb development in amphibia.

Anterior trunk neural folds were exchanged between neurula stages 15 to 16 (Harrison) of several Triturus species and Ambystoma mexicanum. Donor neural crest cells migrated ventrad before and during initial bud formation. They lined the early lumb epidermis and became incorporated into the young blastema. Donor melanophores and non-melanophores contributed substantially to host limb buds.