Unveiling the evolution of neural differentiation mechanisms in animals: a study of the structure and function of the POU-IV/Brn-3 gene regulatory network in Cnidaria.

了解神经系统是如何随着进化时间的推移出现和多样化的，这是生物学中的一个基本问题。这项研究项目将使用海葵，其祖先在6亿多年前从所有其他动物谱系中分离出来，重建动物神经发育的深刻进化史。由此产生的知识将以两种方式有助于理解神经系统的进化：(1)它将提供对6亿多年前神经系统起源至关重要的发育机制的基本见解，以及(2)它将提供有关这些机制在其间如何多样化的新信息。该项目还将通过参与阿肯色州INBRE(IDEA生物医学研究卓越网络)的本科生指导计划，积极让少数族裔本科生直接参与研究，从而扩大少数族裔在STEM中的参与。此外，这项研究将通过使用独特的、非传统的动物模型系统来加强阿肯色大学的研究和教育环境，该系统使学生能够很容易地获得尖端生物技术的第一手体验，如CRISPR-Cas9基因组编辑、下一代测序和共聚焦显微镜。这项研究将增进关于神经系统起源和进化的基础知识，并通过基础科学研究和教育造福社会。在双边动物(如小鼠、蠕虫和苍蝇)中，第IV类POU同源结构域转录因子(POU-IV或BRN-3)在调节神经亚型分化和维持方面发挥着进化上的保守作用。然而，目前尚不清楚Pou-IV功能的保护是否超出了Bilateria，也不清楚在具有神经系统的非双边动物群体中是否存在不同的新调节机制，例如Cnidaria(例如水母、珊瑚和海葵)--Bilateria的姐妹群体。为了解决这一问题，本研究将剖析刺参海葵线虫POU-IV基因调控网络的结构和功能。具体地说，这个项目将集中在1)通过结合深入的基因表达分析与通过CRISPR-Cas9介导的基因组编辑的基因功能分析来定义POU-IV指定的神经亚型，以及2)通过结合基因功能扰动、芯片序列和转录组分析来剖析支撑神经命运规范的POU-IV基因调控网络的结构。本项目由神经系统集群组织计划和建立的刺激竞争研究计划(EPSCoR)联合资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding how nervous systems emerged and diversified over evolutionary time is a fundamental problem in biology. This research project will use sea anemones, whose ancestors split off from all other animal lineages over 600 million years ago, to reconstruct the deep evolutionary history of neural development in animals. The resultant knowledge will contribute to the understanding of nervous system evolution in two ways: (1) it will provide fundamental insights into developmental mechanisms that were critical for the origin of nervous systems over 600 million years ago, and 2) it will provide new information about how these mechanisms have diversified in the intervening time period. This project will additionally broaden participation of underrepresented minorities in STEM by actively involving minority undergraduate students directly in research through participation in the Undergraduate Student Mentoring Program of Arkansas INBRE (IDeA Network of Biomedical Research Excellence). Furthermore, the research will strengthen both the research and educational environments at the University of Arkansas by using a unique, non-traditional animal model system that makes it easy give students first-hand experience with cutting-edge biological technologies such as CRISPR-Cas9 genome editing, Next Generation Sequencing, and confocal microscopy. The research will advance fundamental knowledge about the origin and evolution of nervous systems, as well as benefit society through basic science research and education. In bilaterian animals (e.g. mice, worms and flies), the class IV POU homeodomain transcription factor (POU-IV or Brn-3) plays an evolutionarily conserved role in regulating neural subtype differentiation and maintenance. However, it is unclear whether the conservation of POU-IV function extends beyond Bilateria, or whether divergent, novel regulatory mechanisms exist in non-bilaterian animal groups with nervous systems such as Cnidaria (e.g. jellyfish, corals and sea anemones) – the sister group of Bilateria. To address this problem, the research will dissect the structure and function of the POU-IV gene regulatory network in the cnidarian sea anemone Nematostella vectensis. Specifically, this project will focus on 1) defining neural subtypes specified by POU-IV by combining in-depth gene expression analyses with gene function analyses via CRISPR-Cas9-mediated genome editing, and 2) dissecting the structure of the POU-IV gene regulatory network underpinning neural fate specification by combining gene function perturbation, ChIP-seq, and transcriptome analyses.This project is jointly funded by the Organization Program of the Neural Systems Cluster, and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.