Developmental mechanisms regulating tooth succession and accession in the house shrew (Suncus murinus)

哺乳动物的双齿牙齿替换术的特点是用恒牙代替乳牙。由于老鼠永远不会更换牙齿，本研究以家鼠Suncus Murinus为模型，研究了牙齿的继承和添加对双齿牙齿替换的控制。家鼠牙胚的发育序列表明，相邻的两个牙胚并不是同时发育的，而是有恒定的时间滞后。我们认为，这种牙齿的继承和加入模式可以用一个顺序抑制级联模型来解释，在该模型中，启动的时间和牙齿发育的间隔由相邻牙胚发育之前的抑制决定。

The diphyodont tooth replacement in mammals is characterized by a single replacement of a deciduous dentition by a permanent dentition. Because the mouse never replaces its teeth, this study used the house shrew, Suncus murinus, as a model to investigate the control of the diphyodont replacement by successions and accessions of teeth. The developmental sequence of tooth germs in the house shrew indicates that two adjacent tooth germs do not develop simultaneously, but with a constant time lag. We suggest that this mode of tooth succession and accession can be explained by a sequential inhibitory cascade model in which the timing of initiation and the spacing of tooth development are determined by the inhibition from developmentally preceding adjacent tooth germs.