Hamachi Takeshi, Sasaki Yasunori, Hidaka Kiyoshi, Nakata Minoru
Section of Paediatric Dentistry, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi Higashi-Ku, Fukuoka 812-8582, Japan.
Arch Oral Biol. 2003 Aug;48(8):581-7. doi: 10.1016/s0003-9969(03)00104-3.
The CL/Fr mouse strain develops cleft lip and palate (CLP) spontaneously. In this study, Pax9 mRNA expression was investigated in the palatal shelves during palatal morphogenesis to assess the correlation between secondary palatal morphogenesis and Pax9 expression of CL/Fr embryos with spontaneous cleft lip and palate. The expression of Pax9 mRNA was characterised using whole mount in situ hybridisation with a digoxygenin-labelled probe. In the control strain of C57BL/6 and CL/Fr normal embryos, Pax9 was expressed in the palate, especially along the medial edge (ME), on embryonic day 13.5 (E13.5) and E14.5 when the palatal shelves grew vertically down the side of the tongue and subsequently elevated to a horizontal position, and was down regulated on E15.5 when the palatal shelves met and began fusing. In the cleft embryo, Pax9 was expressed in the ME region but was not down regulated on E15.5. Furthermore, whole mount in situ hybridisation was performed after organ culture, using CL/Fr-N and CL/Fr-BCL palatal shelves dissected and approximated by pairs on E13.5. This showed that Pax9 was still expressed in the ME region in separated palatal shelves of CL/Fr-N and CL/Fr-BCL embryos, while Pax9 expression was down regulated in paired palatal shelves. These expression patterns of Pax9 in normal and cleft embryos during palatal fusion indicate that Pax9 expression is altered in spontaneous cleft lip and palate, and concludes that there is a direct correlation between Pax9 expression and palatal fusion.
CL/Fr小鼠品系会自发出现唇腭裂（CLP）。在本研究中，对腭部形态发生过程中腭突内Pax9 mRNA的表达进行了研究，以评估继发腭部形态发生与患有自发唇腭裂的CL/Fr胚胎的Pax9表达之间的相关性。使用地高辛标记探针通过全胚胎原位杂交来表征Pax9 mRNA的表达。在C57BL/6对照品系和CL/Fr正常胚胎中，在胚胎第13.5天（E13.5）和E14.5时，当腭突沿舌侧垂直向下生长并随后抬高至水平位置时，Pax9在腭部表达，尤其是沿着内侧边缘（ME）表达，而在E15.5时，当腭突相遇并开始融合时，Pax9表达下调。在腭裂胚胎中，Pax9在ME区域表达，但在E15.5时未下调。此外，在器官培养后进行全胚胎原位杂交，使用在E13.5时成对解剖并靠近的CL/Fr-N和CL/Fr-BCL腭突。这表明在CL/Fr-N和CL/Fr-BCL胚胎分离的腭突中，Pax9仍在ME区域表达，而在成对的腭突中Pax9表达下调。Pax9在正常和腭裂胚胎腭部融合过程中的这些表达模式表明，Pax9表达在自发唇腭裂中发生改变，并得出结论：Pax9表达与腭部融合之间存在直接相关性。
