Genetic and Cellular Analysis of Vertebrate Anterior Neurulation

项目总结 神经管缺陷(NTD)，由平面神经板转化为神经管失败所致 神经管闭合，大约每千名新生儿中就有一名发生。当前神经管不能 接近时，它会导致一种称为无脑症的致命出生缺陷，大脑和头骨无法发育。我们的长- 学期目标是使用斑马鱼来确定控制前部闭合的遗传和细胞机制。 神经管。我们发现Nodal信号减弱的斑马鱼胚胎有一个开放的前神经管 类似于无脑畸形的表型。我们之前的研究表明，节点信号的作用是 诱导前中胚层和中内胚层组织。然后，这些组织与 以某种方式覆盖神经上皮，促进神经管闭合。 本提案中的实验将定义节点信令下游的步骤和 前神经形成所需的中胚层/中内胚层的形成。最新的RNAseq屏幕在 梁实验室发现了3,000多个在开放和开放胚胎之间差异表达的基因 封闭的神经管。这些基因中的许多都是与Nodal一起工作的很好的候选者 发出促进神经管关闭的信号。这些候选途径的作用将通过丢失- 功能和抢救实验，将确定它们是否对神经管关闭和 它们是否与节点信号相互作用。本提案的第二部分将定义 防止它闭合的神经上皮。测量细胞极性的生化和细胞技术，细胞 形态、蛋白质定位和表达将定义与开放神经相关的变化 管表型。 这些研究目标将与创建一门将 增加本科生参与假设驱动的原创性研究的机会。在……里面 这门课，本科生的小组将一起工作，以产生一个关于 前神经形成中的RNAseq候选基因之一。然后，他们将通过以下方式检验他们的假设 利用CRISPR/Cas9基因组鉴定一个新的斑马鱼突变体的神经管表型 正在编辑。 哺乳动物的前神经形成需要一个类似的组织，头部间充质，也是它的基础。 发育中的神经管。因此，本科生和研究生的合作研究具有很大的意义 有可能揭示人类无脑症背后的新基因和信号通路。 好了！

PROJECT SUMMARY Neural tube defects (NTD), resulting from a failure in the transformation of a flat neural plate into a closed neural tube, occur in approximately one in every thousand births. When the anterior neural tube fails to close, it results in a fatal birth defect called anencephaly in which the brain and skull fail to develop. Our long- term goal is to use zebrafish to define the genetic and cellular mechanisms that control closure of the anterior neural tube. We found that zebrafish embryos with reduced Nodal signaling have an open anterior neural tube phenotype analogous to anencephaly. Our previous research demonstrated that the role of Nodal signaling is to induce anterior mesodermal and mesendodermal tissues. These tissues then communicate with the overlying neuroepithelium in some way that promotes neural tube closure. The experiments in this proposal will define the steps downstream of Nodal signaling and mesoderm/mesendoderm formation that are required for anterior neurulation. A recent RNAseq screen in the Liang laboratory identified over 3,000 genes that are differentially expressed between embryos with open and closed neural tubes. Many of these genes fall into pathways are good candidates to be working with Nodal signaling to promote neural tube closure. The role of these candidate pathways will be tested through loss-of- function and rescue experiments that will determine whether they are necessary for neural tube closure and whether they interact with Nodal signaling. The second part of this proposal will define defects in the neuroepithelium that prevent it from closing. Biochemical and cellular techniques that measure cell polarity, cell morphology, and protein localization and expression will define the changes that correlate with the open neural tube phenotype. These research goals will be tightly linked to the creation of an “Experimental Biology” course that will increase the opportunities for undergraduate students to participate in hypothesis-driven, original research. In this course, small groups of undergraduate students will work together to generate a hypothesis on the role of one of the RNAseq candidate genes in anterior neurulation. They will then test their hypothesis by characterizing the neural tube phenotype of a new zebrafish mutant they make using CRISPR/Cas9 genome editing. Anterior neurulation in mammals requires a similar tissue, the head mesenchyme, that also underlies the developing neural tube. Thus, this cooperative research by undergraduate and graduate students has great potential to reveal new genes and signaling pathways that could underlie anencephaly in humans. !