Jaw kinesis in snakes: the evolution and development of novel structures and enormous gapes

我们的目标是研究独特的蛇颌的发展和进化。这项研究调查了新结构进化背后的机制，并提供了对颅骨关节如何在胚胎中进化和形成的理解。目的：1.描述玉米蛇胚胎中高度柔韧的颌关节的发育和精确解剖；2.比较和对比蛇颌与蜥蜴和雏鸟的发育，并确定胚胎学中塑造这些骨骼元素的机制。3.使用3D成像、几何形态计量学(R中的编程技巧)和进化建模来了解颌骨多样性的起源，以将发育机制与成体形态相关联。4.开发新的统计模型来模拟从早期的蛇化石到现代的蛇和顶节类群的蛇下巴的进化速度和模式。塔克实验室：这些目标将利用国王学院塔克教授建立的玉米毒蛇克隆(Elaphe Guttata)。将使用免疫组织化学、原位杂交以及增殖和细胞死亡分析来研究颌骨。成像将涉及显微CT和共聚焦显微镜。实验室已经克隆了几个玉米蛇基因(Shh，PTC，Axin2，Lef1)。蛇颌将与其他物种的基因(King‘s可获得的胚胎)在基因表达、形态和细胞动力学方面的差异进行比较。Felicelab：该项目将使用R和进化建模中的尖端成像、3D形态测量分析来量化不同蛇物种的解剖进化速度和模式。学生将开发贝叶斯概率建模的新方法，以测试有关颌骨解剖变异如何产生的假设(即，颌骨之间的相关性是否制约进化？)这些新技术将为分析其他进化新颖性提供一个有用的框架。

We aim to study the development and evolution of the unique snake jaw. This researchinvestigates the mechanisms behind the evolution of novel structures and provides anunderstanding of how cranial joints evolved and form embryonically. Aims: 1. Tocharacterise the development and precise anatomy of the highly flexible jaw joints inthe corn snake embryo 2. To compare and contrast the development of the snake jawwith that of lizards and chicks, and to identify the mechanisms that shape theseskeletal elements during embryology. 3. To correlate developmental mechanisms withadult morphology, across snake species, using 3D imaging, geometric morphometrics(programming skills in R), and evolutionary modeling to understand the origins of jawdiversity. 4. To develop new statistical models to model the tempo and mode ofevolution in the snake jaw, from early fossil snakes to modern snakes and acrossecological groups. Tucker Lab: These aims will take advantage of the corn snakecolony (Elaphe guttata) established by Prof Tucker at King's. The jaw will beinvestigated using immunohistochemistry, in situ hybridisation and analysis ofproliferation and cell death. Imaging will involve microCT and confocal microscopy.Several corn snake genes have already been cloned in the lab (Shh, Ptc, Axin2, Lef1).Snake jaws will be compared to those of other species (embryos available at King's),with respect to differences in gene expression, morphology, and cell dynamics. Felicelab: The project will quantify tempo and mode of anatomical evolution in differentsnake species using cutting-edge imaging, 3D morphometric analysis in R andevolutionary modelling. The student will develop new methods for Bayesianprobabilistic modeling to test hypotheses about how anatomical variation arose in thejaw (i.e., do the correlations among jaw bones constrain evolution?). These newtechniques will provide a useful framework for analysis of other evolutionary novelties.