Van der Heyden C, Huysseune A
Zoological Institute, Ghent University, Ghent, Belgium.
Dev Dyn. 2000 Dec;219(4):486-96. doi: 10.1002/1097-0177(2000)9999:9999<::AID-DVDY1069>3.0.CO;2-Z.
We have used three-dimensional reconstructions from serial sections as well as cleared and stained specimens to infer patterning of the pharyngeal dentition throughout ontogeny in the zebrafish. Each pharyngeal tooth has been monitored from its initiation to its complete disappearance (resorption and shedding). We have identified tooth families and have studied the persistence of the pattern through successive replacements. Teeth arise in two seemingly independent clusters, a ventral and a dorsal cluster, with differing patterning features. The ventral cluster consists of one row of five teeth in which a tooth is first initiated in position four, and subsequent teeth in adjacent positions, posterior and anterior to it. Replacement teeth in odd and even positions are initiated simultaneously during successive odontogenic waves but differ in generation number according to the timing of appearance of the first-generation tooth, i.e., the founder of the tooth family. Up to four teeth of a single tooth family are simultaneously present in early juveniles of which two are usually "co-functional." The number of teeth per tooth family is reduced in older juveniles and adults, reflecting a slowing down of the replacement rate. The consistent way in which the pattern is established and maintained during ontogeny calls for research of the presence of specific molecular controls.
我们利用连续切片的三维重建以及透明和染色标本，来推断斑马鱼整个个体发育过程中咽齿的模式形成。从咽齿开始形成到完全消失（吸收和脱落），我们对每颗咽齿都进行了监测。我们已经识别出牙系，并通过连续替换研究了模式的持续性。牙齿出现在两个看似独立的簇中，一个腹侧簇和一个背侧簇，具有不同的模式特征。腹侧簇由一排五颗牙齿组成，其中一颗牙齿首先在位置4开始形成，随后的牙齿在其相邻位置，即其后和其前。在连续的牙发生波中，奇数和偶数位置的替换牙同时开始形成，但根据第一代牙齿（即牙系的奠基者）出现的时间，其代数不同。在早期幼鱼中，单个牙系中最多同时存在四颗牙齿，其中两颗通常“协同发挥功能”。在年龄较大的幼鱼和成年鱼中，每个牙系的牙齿数量减少，这反映了替换率的下降。在个体发育过程中建立和维持模式的一致方式，需要对特定分子控制的存在进行研究。
