转录因子Pax3和Pax7（Pax3/7）在脊椎动物发育中功能重要。我们前期研究显示在鸡胚脊髓中异常表达Pax3/7导致神经细胞聚集和轴突路径障碍，且与Wnt/β-catenin和Sonic Hedgehog（Shh）通路及钙粘蛋白表达分布相关联，但机制不明。据此提出Pax3/7相互作用通过Wnt/β-catenin和Shh信号通路调控钙粘蛋白表达，进而影响发育脊髓中神经元分化和轴突路径选择。本研究将通过电转基因技术结合CRISPR-Cas9体系改变Pax3/7表达，采用脊髓片和神经元培养及实时观察等技术分析神经元分化迁移和轴突生长、OpenBook分析细胞聚集和轴突投射等现象，通过组学分析证实参与的分子与信号通路，从活体-组织-细胞-分子层次研究Pax3/7在脊髓发育中的功能和调控，尝试Pax3/7阳性神经细胞移植修复脊髓损伤，将为阐明Pax3/7的作用机理及其潜在临床应用提供实验资料。

Transcription factors Pax3 and Pax7 (Pax3/7) play importmant roles during vertebrate development. Our previous study showed that abnormal expression of Pax3/7 results in disorders of neural cell aggregation and axon pathway finding during chicken embryonic spinal cord development. More analysis explored that Pax3/7 are involved in Wnt/beta-catenin and Sonic Hedgehog（Shh）signaling pathways, aslo related to the expression and distribution of cadherins, however, little is known about their regulation mechanism. According to above, we hypothesize that Pax3/7 may regulate cadherin expression through Wnt/beta-catenin and Shh signaling pathways to affect neuron differentiation and axon pathway finding during the spinal cord development. In this study, we aim to investigate the misexpression of Pax3 and Pax7 in the developing embryonic spinal cord with in vivo electroporation combining with CRISPR-Cas9 system, to analyze neuron differentiation, migration and aggregation with spinal cord slice, neuron culture and real-time observation, and to confirm the involved molecules and signaling pathways with transcriptome sequencing analysis. Finally, we will demonstrate the function and regulation of Pax3/7 at four levels, living embryo - spinal cord tissue slice - cells - molecules with different methods, during the spinal cord development. Transplatation of Pax3/7 positive neural cells will be used to treat mouse spinal cord injury. This project will provide experimental data to reveal functional mechanism of Pax3/7 and their potential clinical application.