title: [Expression of Shh, Ptc1, Ptc2 mRNA in the cap stage of mouse molar].
abstract: OBJECTIVE
  To investigate the expression of Shh and its receptors Ptc1 and Ptc2 mRNA in the cap stage of mouse molar and discuss its role in early tooth morphogenesis.
  
  
  METHODS
  The embryonic mouse heads of early tooth development (E10.5 - E15.5) were obtained and 5 micro m serial sections were made. Immunohistochemical staining of PCNA was carried out by SP method. The expression pattern of Shh, Ptc1, and Ptc2 mRNA was analysed by in situ hybridization.
  
  
  RESULTS
  E14.5, outer dental epithelium, inner dental epithelium, stellate reticulum and underlying dental mesenchyme were PCNA positive. Most of the enamel knot cells were PCNA negative. A few of the enamel knot cells were PCNA positive. Shh, Ptc1, and Ptc2 mRNA were strongly expressed in outer dental epithelium, inner dental epithelium, stellate reticulum and the enamel knot.
  
  
  CONCLUSIONS
  In the cap stage, Shh as a paracrine and autocrine signaling molecule might stimulate epithelium and mesenchyme proliferation.
authors.affiliation: Key Laboratory for Oral Biomedical Engineering, School of Stomatology, Wuhan University, Wuhan 430079, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhi-feng
authors.initials: ZF
authors.lastname: Wang
authors.forename: Zhi-jun
authors.initials: ZJ
authors.lastname: Sun
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Bing
authors.initials: B
authors.lastname: Fan
mesh_terms: D000818:Animals; D053823:Hedgehog Proteins; D051379:Mice; D008963:Molar / Q000378:metabolism; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D012333:RNA, Messenger / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics; D014083:Tooth Germ / Q000254:growth & development / Q000378:metabolism*; D015534:Trans-Activators / Q000096:biosynthesis*
chemical_list: D053823:Hedgehog Proteins; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; C000606240:Ptch1 protein, mouse; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D015534:Trans-Activators