The Non-Vertebrate Chordate Oikopleura and Evolution of Vertebrate Developmental Innovations

脊椎脊索动物具有非脊椎脊索动物所不具有的创新，包括神经嵴、神经源性基板、骨骼特征和扩增的基因组。该项目的长期目标是了解脊椎动物如何从非脊椎脊索动物进化而来。这项工作测试的假设，脊椎动物进化的能力，神经板边缘基因打开神经嵴说明。该项目在Oikopleura dioica中测试了这一假设的预测，Oikopleura dioica是一种具有完全测序基因组的幼虫，使用新方法一次改变数百个胚胎。幼虫类是普遍存在的海洋生物，被认为是对海洋生物量和碳循环做出重大贡献的基础脊索动物。 将克隆神经嵴相关基因的Oikopleura直系同源物，并使用原位杂交来了解其表达模式。神经嵴相关的基因调控网络Oikopleura将进行解剖与Oikopleura的直系同源的关键嵴相关基因的功能的增益和损失的实验，并通过原位杂交和基因组微阵列的结果将进行评估。公众将进一步了解幼虫类动物在环境中的作用和脊椎动物起源的调查。实现这些目标将定义发育机制，脊椎动物进化到发展一个完整的神经嵴和照明机制，进化新奇的出现。由于幼虫类动物，特别是Oikopleura dioica，从大气中清除大量温室气体二氧化碳，长期储存在海洋深处，因此更好地了解幼虫类生物学将有助于阐明对全球变暖的理解。该项目将教育学生了解幼虫类动物在生态学和进化生物学中的作用，并将指导代表性不足群体的代表，特别是少数民族大学生。

Vertebrate chordates have innovations not shared by non-vertebrate chordates, including neural crest, neurogenic placodes, skeletal features, and an amplified genome. The project's long-term objective is to learn how vertebrates evolved from non-vertebrate chordates. This work tests the hypothesis that vertebrates evolved the ability of neural plate border genes to turn on neural crest specifiers. The project tests predictions of the hypothesis in Oikopleura dioica, a larvacean with a fully sequenced genome, using novel methods to alter hundreds of embryos at once. Larvaceans are ubiquitous marine organisms that are considered basal chordates that contribute substantially to the biomass and carbon cycling of oceans. Oikopleura orthologs of neural crest-related genes will be cloned and in situ hybridization will be used to learn their expression patterns. Neural crest-related gene regulatory networks in Oikopleura will be dissected by performing gain- and loss-of-function experiments with Oikopleura orthologs of key crest-related genes, and results by in situ hybridization and genomic microarray will be evaluated. Public understanding will be enhanced of the roles of larvaceans in the environment and in the investigation of vertebrate origins. Achieving these aims will define developmental mechanisms that vertebrates evolved to develop a full blown neural crest and illuminate mechanisms by which evolutionary novelties arise. Because larvaceans, especially Oikopleura dioica, remove large quantities of the greenhouse gas carbon dioxide from the atmosphere for long-term storage in ocean depths, a better understanding of larvacean biology will help illuminate understanding of global warming. The project will educate school children about the role of larvaceans in ecology and the science of evolutionary biology and will mentor representatives of underrepresented groups, particularly minority undergraduates.