title: [Retinoic acid signal pathway regulation of zebra fish tooth development through manipulation of the differentiation of neural crest].
abstract: OBJECTIVE
  To investigate the mechanism of retinoic acid (RA) signal in dental evolution, RA is used to explore the influence of the mechanism on neural crest's migration during the early stage of zebra fish embryos.
  
  
  METHODS
  We divided embryos of wild type and transgenic line zebra fish into three groups. 1 x 10(-7) to 6 x 10(-7) mol x L(-1) RA and 1 x 10(-7) mo x L(-1) 4-diethylaminobenzaldehyde (DEAB) were added into egg water at 24 hpf for 9 h. Dimethyl sulfoxid (DMSO) with the concentration was used as control group. Then, antisense probes of dlx2a, dlx2b, and barxl were formulated to perform whole-mount in situ hybridization to check the expressions of the genes in 48 hpf to 72 hpf embryos. We observed fluorescence of transgenic line in 4 dpf embryos.
  
  
  RESULTS
  We obtained three mRNA probes successfully. Compared with DMSO control group, a low concentration (1 x 10(-7) mol x L(-1)) of RA could up-regulate the expression of mRNA (barx1, dlx2a) in neural crest. Obvious migration trend was observed toward the pharyngeal arch in which teeth adhered. Transgenic fish had spreading fluorescence tendency in pharyngeal arch. However, a high concentration (4 x 10(-7) mol x L(-1)) of RA malformed the embryos and killed them after treatment. One third of the embryos of middle concentration (3 x 10(-7) mo x L(-1)) exhibited delayed development. DEAB resulted in neural crest dysplasia. The expression of barxl and dlx2a were suppressed, and the appearance of dlx2b in tooth was delayed.
  
  
  CONCLUSIONS
  RA signal pathway can regulate the progenitors of tooth by controlling the growth of the neural crest and manipulating tooth development
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Xing
authors.initials: X
authors.lastname: Huang
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Xu
authors.forename: Deqin
authors.initials: D
authors.lastname: Yang
mesh_terms: D000818:Animals; D001934:Branchial Region; D002454:Cell Differentiation / Q000187:drug effects; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D017403:In Situ Hybridization; D009432:Neural Crest / Q000187:drug effects; D009805:Odontogenesis; D015398:Signal Transduction; D014070:Tooth / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism*
chemical_list: D014212:Tretinoin