Timing of odontogenic neural crest cell migration and tooth-forming capability in mice.
The mammalian tooth develops through sequential and reciprocal interactions between cranial neural crest (CNC)- derived ectomesenchymal cells and the stomadial epithelium. Classic tissue recombination studies demonstrated that premigratory CNC cells and CNC-derived ectomesenchymal cells possess odontogenic capacity and can respond to oral epithelial signals to form a tooth, suggesting that the CNC cells contributing to odontogenic tissue are not prespecified. Here we show that, in mice, CNC cells have populated the forming first branchial arch before the 9-somite stage and continue to migrate into the arch by the 13-somite stage. Grafts of the first arch from the 10-somite embryo or earlier yielded membranous bone and cysts but no teeth after subrenal culture. However, grafts of the first arch with its dorsally adjacent tissue containing migrating neural crest cells from the same age embryos gave rise to teeth. In contrast, teeth formed in first arch grafts that do not contain migrating neural crest cells from embryos with 12 or more somites. Interestingly, the acquisition of tooth forming capability in the first arch coincides with the onset of Fgf8 expression in the oral epithelium. These results suggest that there exists a population of odontogenic neural crest cells that migrates into the first arch between the 10- and 12-somite stages. These cells either possess odontogenic potential and are able to initiate tooth development, or can respond to odontogenic signals derived from the oral epithelium to support tooth formation.
Zhang
Yanding
Y
College of Bioengineering, Fujian Teacher's University, Fuzhou, Fujian Province, Peoples' Republic of China.
Wang
Shusheng
S
Song
Yiqiang
Y
Han
Jun
J
Chai
Yang
Y
Chen
YiPing
Y
D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D005260:Female; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000235:genetics; D019426:Integrases / Q000235:genetics; D007668:Kidney / Q000166:cytology; D051379:Mice; D008822:Mice, Transgenic; D009432:Neural Crest / Q000166:cytology* / Q000196:embryology*; D009924:Organ Culture Techniques; D011247:Pregnancy; D011518:Proto-Oncogene Proteins / Q000235:genetics; D014070:Tooth / Q000166:cytology* / Q000196:embryology*; D014764:Viral Proteins / Q000235:genetics; D051153:Wnt Proteins; D029961:Zebrafish Proteins
C496457:Fgf8 protein, mouse; D011518:Proto-Oncogene Proteins; D014764:Viral Proteins; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors; C045073:Cre recombinase; D019426:Integrases