Molecular Dissection of Tooth Shape

描述（由申请人提供）： 牙发生是上皮-间充质信号传导的典型例子。 与早期牙齿发育的详细信息相比，人们对牙齿形状差异的基因知之甚少。 这些信息是了解脊椎动物牙齿多样性背后的机制，哺乳动物异齿的进化，以及某些人类牙齿疾病的根本原因所必需的。 在重现牙齿形状表型的小鼠中没有基因敲除，并且其他模式生物（斑马鱼、青蛙、鸡）要么在口颌中缺乏牙齿，要么表现出根本衍生的牙列。 在这里，描述了一个新的系统，其中研究牙齿形态的变化。 Labeotropheus fuelleborni（Lf）和Metriaclima zebra（Mz）是产于非洲马拉维湖的两种慈鲷科鱼类，分别具有三尖和二尖牙齿。 该建议描述了与来自Lf和Mz互交的F2鱼的牙齿形状差异相关的基因组区域的鉴定。 特定候选基因的作用是通过在同一个杂交中定位这些位点和通过研究亲本和杂交胚胎中候选基因的表达模式来评估的。 这些数据将有助于对脊椎动物牙齿形状差异的分子理解。

DESCRIPTION (provided by applicant): Odontogenesis is a classic example of epithelial-mesenchymal signaling. In contrast to the bounty of information regarding the specification of early tooth development, little is know about the genes responsible for differences in tooth shape. This information is needed to understand the mechanisms behind vertebrate tooth diversity, the evolution of mammalian heterodonty, and the underlying cause of certain human dental disorders. There are no genetic knock-outs in mouse that recapitulate tooth shape phenotypes and other model organisms (zebrafish, frog, chick) either lack teeth in the oral jaws or exhibit radically derived dentitions. Here, a new system in which to study variance in tooth morphology is described. Labeotropheus fuelleborni (Lf) and Metriaclima zebra (Mz), two species of cichlid fishes from Lake Malawi, Africa have tricuspid and bicuspid teeth respectively. This proposal describes the identification of genomic regions associated with tooth shape differences in F2 fish derived from the inter-cross of Lf and Mz. The role of specific candidate genes is evaluated by mapping these loci in the same cross and by studying patterns of candidate gene expression in parental and hybrid embryos. These data will contribute to a molecular understanding of differences in vertebrate tooth shape.