Evolution and development of skeletal patterning

该研究项目将研究脊椎动物骨骼的发育和进化生物学，跨越大规模的进化转变。具体来说，它将利用形状描述和基因表达的定量方法探索鱼类到四足动物和恐龙到鸟类过渡的发育和进化整合和骨骼变异之间的相互作用。选择这两种过渡是因为它们有丰富的化石记录和丰富的相关现存物种的发育生物学。一套互补的项目旨在建立一个广泛的跨学科项目，研究范围从遗传进化，到发育力学，到生物成像和定量表型学，到进化模式，速率和变异。***研究将集中于成对附属物（鳍和四肢）和中轴柱（脊柱和尾巴）的发育和进化。两者都经历了从鱼类到四足动物和从恐龙到鸟类的巨大进化变化，预计它们也经历了同样巨大的进化变化。项目的第一阶段将重建这些解剖结构在这两个过渡期间的进化变化。这将通过将定性和定量数据添加到现有数据集中来估计这些转变的解剖进化速率和类型。第二阶段将在选定的鱼类、两栖动物、哺乳动物、爬行动物和鸟类的现存胚胎中，对这两个解剖区域的内骨骼的骨骼发育（从未分化的间质，到凝聚，到软骨，然后骨化）进行成像。在我的指导下，这项成像将在一种新型纳米聚焦微型CT机上广泛应用于软组织成像，该机器最近获得了CFI创新基金（PI: Vogel，一项综合定量生物学计划[IQBI]）的奖励。第三阶段将测试这些区域骨骼模式早期阶段的遗传和表观遗传（环境）控制。一些结果预计将突出可能与快速进化变化有关的发育开关点，而其他结果可能突出发育保护。这项研究将推导出骨骼发育和进化的工作模型。这些结果将应用于我们对生物系统如何进化以及发育生物学如何影响大规模进化变化的理解。其他应用是开发成像、量化和比较解剖数据的有效工作流程。这对于客观地估计进化关系、描述发育变异和医学成像具有巨大的意义。

The research program will examine the developmental and evolutionary biology of the vertebrate skeleton across large scale evolutionary transitions. Specifically, it will explore the interplay between developmental and evolutionary integration and variation in the skeleton across the fish to tetrapod and dinosaur to bird transitions using quantitative methods of shape description and gene expression. The two transitions are chosen because of their rich fossil record and wealth of developmental biology of relevant extant species. A set of complimentary projects are designed to bridge a broad interdisciplinary program that researches a spectrum from genetic evolution, to developmental mechanics, to biological imaging and quantitative phenomics, to evolutionary patterns, rates, and variation. ***Research will focus on the development and evolution of paired appendages (fins and limbs) and the axial column (spine and tail). Both have undergone dramatic evolutionary changes across the fish-tetrapod and dinosaur-bird transitions and are expected to have had equally dramatic developmental changes. The first phase of projects will reconstruct the evolutionary changes of these anatomies across these two transitions. This will be done by adding qualitative and quantitative data to existing datasets to estimate rates and types of anatomical evolution at these transitions. The second phase will image the skeletal development (from undifferentiated mesenchyme, to condensations, to chondrified, and then ossified bone) of the endoskeleton of these two anatomical regions in extant embryos of selected fishes, amphibians, mammals, reptiles, and birds. This imaging will make intensive use soft tissue imaging with a new nano-focus micro CT machine under my supervision recently awarded in a CFI Innovation Fund (PI: Vogel, An integrated quantitative biology initiative [IQBI]). The third phase will test for genetic and epigenetic (environmental) control of early stages of skeletal patterning in these regions. Some results are expected to highlight developmental switch points that may be associated with rapid rates of evolutionary change whereas others may highlight developmental conservation. ***This research will derive a working model of skeletal development and evolution. The results will have application to our understanding of how biological systems evolve and how developmental biology influences large scale evolutionary change. Other applications are the development of an efficient work flow for imaging, quantifying, and comparing anatomical data. This has enormous implications for objectively estimating evolutionary relationships, describing developmental variation, and medical imaging.