Directed Bmp4 Expression In Neural Crest Cells Generates The Abnormal Lacation Of Molar

Mammalian tooth structure is relatively simple and has its unique development process, and therefore is regarded as one of the best models of organ development. The process of tooth development is highly regulated by sequential and reciprocal signaling molecules between the epithelium and mesenchyme. These signal molecules are classified as four family, including SHH, BMP, FGF and WNT. BMP signaling pathway plays a key role in the development of tooth. The accurate control of these various factors in BMP signaling pathway reduce the state of BMP signal activity to homeostasis, the disruption of which will lead to the abnormity of tooth development. Bmp4 is an important growth factor in BMP signaling pathway. It can induces the expression of various factors related the tooth morphogenesis. In this study, we cross pMes-Bmp4 mice with Wntl Cre mice to obtain the Wntl Cre;pMes-Bmp4 mice with overexpression of Bmp4 in mesenchyme. The enhanced expression of Bmp4 results in a smaller body size, incomplete fusion of jaws, defect in eye tissue comparing to the wild type. As well as, the Wntl Cre;pMes-Bmp4 mice died immediately after birth. In addition, severous abnormities exist in molar tooth,but not in incisors. The abnormal molar located in the joint of maxillary and mandible. Further, we examine the significant gene in the tooth development, including Shh,Fgf8,Pax9 and Msxl. And we found the pattern of these genes expressed in the Wntl Cre;pMes-Bmp4 mice are similar to the wild type. All these results suggest that the BMP signaling is crucial to the position of tooth.