Progressive acquisition of novel neural crest derivatives along the neural axis during vertebrate evolution

脊椎动物进化过程中沿神经轴逐步获得新型神经嵴衍生物

基本信息

批准号：
10617203
负责人：
Marianne Bronner
金额：
$ 57.13万
依托单位：
CALIFORNIA INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-05-15 至 2027-04-30
项目状态：
未结题

项目摘要

The neural crest is a uniquely vertebrate cell type that is thought to have played an important role in vertebrate evolution by forming peripheral ganglia and jaws, thus facilitating predation and expansion of the brain. We recently identified a “cranial-specific” neural crest transcriptional subcircuit in jawed vertebrates (gnathostomes) that imbues this neural crest population with the unique ability, absent from trunk neural crest, to form craniofacial cartilage that is critical for jaw formation. Here, we propose to examine whether homologous genes are expressed in the cranial premigratory neural crest of lamprey, a jawless basal vertebrate (agnathan). Our preliminary results suggest that many of these genes are “missing” from the lamprey's premigratory cranial neural crest, thus challenging the hypothesis that invention of neural crest in vertebrates gave rise to a “New Head”. Accordingly, we hypothesize that there was progressive expansion of neural crest derivatives during the course of vertebrate evolution. This likely occurred by addition of new enhancer elements into the premigratory neural crest that conferred novel developmental potential onto this cell population. As case in point, lamprey lack a vagal neural crest that in gnathostomes forms the enteric nervous system. To test this hypothesis, we will perform lineage analysis, analyze transcription factors and regulatory regions of selected genes across agnathan and gnathostomes. We will identify putative enhancers, dissect their regulatory inputs, and test the ability of these regions to drive reporter expression in lamprey as well as cross-species, in the zebrafish. The results promise to elucidate how new cell types arose during vertebrate evolution under the umbrella of the neural crest.

神经rest是一种独特的脊椎动物细胞类型，被认为发挥了重要的作用通过形成外围神经节和下巴来在脊椎动物进化中的作用，从而支持捕食和大脑的扩展。我们最近确定了一个“颅骨特异性”的神经rest转录颌脊椎动物（gnathostomes）中的亚电路，使这种神经rest种群与树干神经rest不具有的独特能力，形成颅面软骨，这对于下巴至关重要形成。在这里，我们建议检查是否在兰lamp裂颅底神经rest，一种无知的基本脊椎动物（Agnathan）。我们的初步结果表明，这些基因中的许多基因都从七lamp中“缺失” 怀孕颅神经rest，从而提出了神经rest的发明的假设在脊椎动物中，引起了“新的头”。根据，我们假设有在脊椎动物进化过程中，神经元衍生物的逐渐扩展。这可能是通过将新的增强子元素添加到前移民神经波峰中发生的为该细胞种群提供了新的发育潜力。例如，七lamp不平 gnathostomes中形成肠神经系统的迷走性中性波峰。测试这个假设，我们将进行谱系分析，分析转录因子和调节性跨Agnathan和gnathostomes的选定基因区域。我们将确定推定的增强剂，剖析其监管输入，并测试这些区域推动记者的能力斑马鱼中的七lamp虫和跨物种的表达。结果有望阐明在中性的雨伞下脊椎动物演化期间新细胞类型的产生方式波峰。