Reciprocal interactions between epithelial and neural crest-derived mesenchymal cells have been recognized in the evolutionary modulation of tetrapod odontodes, skeletal structures that include the teeth and tooth-integrated basal tissue. Using cell-tracking experiments, it has been demonstrated that mandibular neural crest cells, labelled during migration, extensively populate dental papillae of all tooth phenotypes of the lobe-finned fish, the Australian lungfish (Neoceratodus forsteri). Here, I report on an extension of this experimental study that earliest migrating NC cells are able to differentiate into odontogenic ectomesenchyme. Using vital dye cell-tracking to mark the mesencephalic neural crest prior to migration, I have found that the corresponding population of earliest migratory cells selectively relocated to dental papillae of both temporary and permanent dentitions of Neoceratodus. I noticed a gradient in distribution of the labelled cells which populated posterior teeth, pterygoid and prearticular (including associated trabecular and Meckelian cartilages; major relocation) much more densely than those in anterior marginal positions, temporary and vomeral permanent teeth (minor relocation). Contrary to mice and zebrafish, the odontogenic potency of mesencephalic neural crest cells is already programmed at the onset of the migration event in lungfish. This may imply that the morphogenic potential of mesencephalic neural crest cells to form teeth has been heterochronically shifted and constrained to later migratory populations of neural crest cells during the developmental evolution of derived tetrapods, or/and arrested in their expression in the oral development of some modern osteichthyans.

上皮细胞和神经嵴来源的间充质细胞之间的相互作用已在四足动物齿突、骨骼结构（包括牙齿和牙齿整合的基底组织）的进化调节中得到认可。使用细胞追踪实验，已经证明在迁移过程中标记的下颌神经嵴细胞广泛分布于叶鳍鱼、澳大利亚肺鱼 ( Neoceratodus forsteri)的所有牙齿表型的牙乳头中。）。在这里，我报告了这项实验研究的扩展，即最早迁移的 NC 细胞能够分化为牙源性外间充质。在迁移前使用活体染料细胞追踪标记中脑神经嵴，我发现相应的最早迁移细胞群选择性地重新定位到新角龙临时和永久牙列的牙乳头. 我注意到后牙、翼状骨和关节前（包括相关的小梁和 Meckelian 软骨；主要移位）的标记细胞分布梯度比前边缘位置、临时和犁骨恒牙（次要移位）中的细胞密度高得多。与小鼠和斑马鱼相反，中脑神经嵴细胞的牙源性效力在肺鱼迁移事件开始时就已经被编程。这可能意味着在衍生四足动物的发育进化过程中，中脑神经嵴细胞形成牙齿的形态发生潜力已被异时转移并限制到后来迁移的神经嵴细胞群，或/和在某些口腔发育中的表达停滞。现代骨鱼。