Coordinated timing of tooth and jaw development

随着牙齿和下颚的生长，它们必须配合在一起才能正常工作，让动物吃东西。因为牙齿位于颌骨内，颌骨形状或大小的任何发育或进化变化都会不可避免地影响牙齿，反之亦然。了解一个身体部位是如何发育的，就是了解它是如何进化的。目前尚不清楚牙齿和下颚发育的时间是如何协调的，以便这些部分在产前和产后发育期间正确地“配合”在一起。我的实验室旨在解释牙齿和下颌的发育速度是如何以协调的方式进化的。一种说法是，牙齿发育的时间是由颌骨组织发出的信号控制的，反之亦然。然而，有充分的证据表明，事实恰恰相反：牙齿和颌骨的发育速度是自然选择的，是平行的，牙齿和颌骨组织之间没有相互影响。我的建议旨在利用互补的遗传、统计和成像数据以及哺乳动物模型在产前和产后发育的各个阶段来解决这个研究问题。为了测试牙齿和下颚在发育时间方面是否都有自己的非相互作用的基因控制网络，我的实验室将分析发育中的牙齿和下颚组织的基因表达。利用高分辨率的三维计算机断层扫描（CT）图像，结合统计工具，我们还将测试牙齿开始发育的时间是否取决于它们在发育中的颚骨中有多少空间。我们的研究将开始填补科学知识的基本空白，帮助解释颌骨和牙齿的发育是如何及时协调的。这一发现将进一步阐明牙齿和下颚是如何在现存和灭绝的哺乳动物中发展和进化出如此惊人的各种不同的功能形式的。

As teeth and jaws grow they must fit together to work properly and allow an animal to eat. Because teeth sit within the jawbone, any developmental or evolutionary changes in jaw shape or size will invariably affect the teeth and vice versa. To understand how a body part develops is to understand how it may have evolved. It is not known how the timing of tooth and jaw development is coordinated such that these parts "fit" together properly during pre- and postnatal growth. My lab aims to explain how the pace of tooth and jaw development has evolved in a coordinated way. One option is that the timing of tooth development is controlled by signals from the jaw tissues, and vice versa. However, good evidence suggests that the opposite is true: the pace of tooth and jaw development has been naturally selected to run in parallel with no cross-talk between tooth and jaw tissues. My proposal aims to tackle this research question using complimentary genetic, statistical and imaging data alongside mammalian models at various stages of pre- and postnatal development. To test if teeth and jaws each have their own non-interacting network of genetic controls with respect to developmental timing, my lab will analyze gene expression in developing tooth and jaw tissues. Using high-resolution 3D computed-tomography (CT) images of jaws and teeth in tandem with statistical tools we will also test if the times at which teeth start to develop are dictated by how much space exists for them in the developing jawbone. Our research will begin to fill a fundamental gap in scientific knowledge by helping to explain how jaw and tooth development is coordinated in time. This insight should further clarify how teeth and jaws have developed and evolved such an amazing variety of different yet functional forms across living and extinct mammals.