Functional analysis for molecular interaction through a new member of the immunoglobulin superfamily in tooth germ development

原原蛋白（Prtg）是胚胎第10天小鼠下颌骨高度表达的基因。5 (E10汽油。5）. Prtg是大肠癌（DCC）中缺失基因家族的新成员。本研究探讨了Prtg在小鼠下第一磨牙牙胚发育中的功能意义。Ptrg在器官发生早期优先表达。Prtg在E10的间充质和口腔上皮细胞中广泛表达。5下颌骨。E12后Prtg的表达。0在下颌骨明显减少，并且局限于可能形成牙芽的区域。培养E10中Prtg的反义抑制实验。5个下颌骨出现明显的牙胚生长抑制。小鼠E10中Bmp-4的表达明显降低。Prtg抑制24小时后5下颌骨。这些结果表明Prtg可能与小鼠下第一磨牙牙胚的初始形态发生有关。此外，Ifrg15、L21和ATPase6基因的原位表达表明，这些基因参与了牙胚以及其他颅面器官的起始和发育。其他检测结果也表明，Tβ4通过调控牙源性相关基因的表达参与了牙胚发育的早期阶段。

Protogenin(Prtg) has been identified as a gene that is highly expressed in the mouse mandible at embryonic day 10. 5(E10. 5). Prtg is a new member of the deleted in colorectal carcinoma(DCC) family. This study examined the functional implications of Prtg in the developing tooth germ of the mouse lower first molar. Ptrg is preferentially expressed in the early stage of organogenesis. Prtg was widely expressed in the mesenchymal and oral epithelial cells in the E10. 5 mandible. The expression of Prtg after E12. 0 was markedly reduced in the mandible, and was restricted to the area where the tooth bud was likely to be formed. An antisense inhibition assay for Prtg in cultured E10. 5 mandibles showed a significant growth inhibition in the tooth germ. Bmp-4 expression had significantly been decreased in the mouse E10. 5 mandible at 24 hr after Prtg inhibition. These results indicated that the Prtg might be related to the initial morphogenesis of the tooth germ in the mouse lower first molar. In addition, in situ expression of Ifrg15, L21 and ATPase6 genes suggest that these genes participate in the initiation and the development of the tooth germ as well as those of the other craniofacial organs. Other examination results also demonstrated that Tβ4 is involved in the early stage of tooth germ development by regulation of the odontogenesis-related gene expression.