Identifying genetic pathways and cellular sources for neural regeneration in adult animals

项目总结/摘要 具有全身再生能力的成年动物的任务是忠实地替换任何缺失的细胞类型， 包括神经系统内的无数细胞类型。大部分关于图案的知识， 神经元群体的特化来自专注于胚胎发育的工作;然而，有限的 已经进行了工作，以确定再生或重新规范整个 成年动物的神经系统。该项目的总体目标是揭示细胞和 神经元细胞特化、分化和替换的分子机制， 成年动物的背景下，使用高度再生的acoel研究模型，Hofstenia miamia。霍夫斯特尼亚 有一个由不同类型的神经细胞组成的有组织的神经系统，它可以完全再生， 一群多能成体干细胞称为“新胚细胞”。值得注意的是，Hofstenia适合机械化 再生的研究，并提出了几个优势，更完善的无脊椎动物再生 模型，包括可获得的胚胎，这些胚胎能够进行基于CRISPR/Cas9的基因组编辑， 转基因这个项目将提出两个关于成人神经系统再生的主要问题 神经系统：1）再生过程中神经细胞类型多样性的分子/遗传调节因子是什么？ 2)什么是细胞的来源和动力学的基础分化的神经群体， 再生？单细胞RNA测序将识别神经细胞类型多样性的候选调节因子，重点关注 转录因子和受体，在再生过程中。我们初步的scRNAseq数据使我们能够 假设sox 4、vax 1和nkx 2.4同源物是神经分化的重要调节因子。系统性RNAi 结合成人显微镜检查，将确定控制神经细胞类型的分子机制， 再生过程中的身份。同时，我们计划利用转基因标记技术来鉴定神经干 细胞群，确定它们的动态和贡献分化的神经群体， 再生这两个问题使我们能够验证一个假设，即单个神经干细胞群 亚功能化以形成霍夫斯滕氏菌内的祖细胞亚型。发现的细胞和分子机制 在这项工作中，成人神经系统的再生有可能告知人类再生 关于神经退行性疾病的药物。我对F31的目标是装备自己， 在发育生物学终身职业所需的计算，遗传和理论技能， 揭示动物再生的复杂性。器官与进化系 哈佛大学的生物学是这种培训的首要机构。

Project Summary/Abstract Adult animals capable of whole-body regeneration are tasked with faithfully replacing any missing cell type, including the myriad of cell types within the nervous system. Most knowledge regarding the patterning and specification of neuronal populations comes from work focusing on embryonic development; however, limited work has been performed to identify mechanisms underlying the regeneration or re-specification of entire nervous systems within adult animals. The overall objective of this project is to uncover the cellular and molecular mechanisms that underlie neuronal cell specification, differentiation, and replacement within the context of an adult animal, using the highly regenerative acoel research model, Hofstenia miamia. Hofstenia has an organized nervous system composed of different neural cell types that it can regenerate fully because of a population of pluripotent adult stem cells called ‘neoblasts’. Notably, Hofstenia is amenable to mechanistic studies of regeneration and presents several advantages over more well-established invertebrate regeneration models, including accessible embryos that have enabled CRISPR/Cas9-based genome editing and stable transgenesis. This project will ask two major questions about nervous system regeneration within the adult nervous system: 1) What are the molecular/genetic regulators of neural cell type diversity during regeneration? 2) What are the cellular sources and dynamics that underlie differentiation of neural populations during regeneration? Single-cell RNAseq will identify candidate regulators of neural cell type diversity, focusing on transcription factors and receptors, during regeneration. Our preliminary scRNAseq data allows us to hypothesize sox4, vax1, and nkx2.4 homologs as important regulators of neural differentiation. Systemic RNAi in combination with microscopy in adults will identify the molecular mechanisms governing neural cell type identity during regeneration. In parallel, we plan to utilize a transgenic labeling technique to identify neural stem cell populations, determining their dynamics and contributions to differentiated neural populations during regeneration. These two questions allow us to test the hypothesis that a single neural stem cell population subfunctionalizes to form progenitor subtypes within Hofstenia. Cell and molecular mechanisms discovered in the regeneration of the adult nervous system in this work have the potential to inform human regenerative medicine with regards to neurodegenerative disease. My goal for the F31 is to equip myself with the computational, genetic, and theoretical skills necessary for a lifetime career in developmental biology to uncover the intricacies associated with animal regeneration. The Department of Organismic and Evolutionary Biology at Harvard University is a premier institution for this training.