核仁蛋白作为核糖体RNA合成以及核糖体组装的主要参与者，对核糖体生物合成过程的调节至关重要，核仁蛋白突变导致特定组织器官的异常和病变。研究不同核糖体生物合成相关蛋白独特功能，阐明其作用机制将为核糖体病变的组织特异性提供线索。我们前期研究利用CRISPR/Cas9技术，构建了模式动物斑马鱼核仁因子esf1基因突变体。发现esf1基因突变导致斑马鱼咽弓软骨严重缺失，细胞凋亡等表型，并且发育缺陷和p53信号通路密切相关。本项目拟在前期发现esf1在早期发育中的功能基础上，以斑马鱼为模式动物，利用斑马鱼体外受精、体外发育的优势，通过构建esf1、tp53双基因突变体、体内过表达等方法，结合体外实验，探讨esf1影响胚胎发育的机制，明确其是否参与调控p53的稳定性以及核糖体生物合成。研究结果将全面揭示esf1在动物早期胚胎发育中的地位作用，最终为斑马鱼作为研究核仁蛋白功能的模式生物提供依据。

Nucleolar proteins which involved in ribosome RNA synthesis and assembly play very important role in ribosome biogenesis. Mutations in nucleolar proteins often cause tissue-specific disease. The mechanisms underlying the tissue proclivity in ribosomopathies are need to be defined. Recently our research showed that a novel zebrafish craniofacial mutant, esf1 mutants, generated via the CRISPR/ Cas9 system exhibited a phenotype because of cranial NCCs defects. The esf1 mutants show that they are lack of all virtually pharyngeal arch cartilages, defects in eye, brain, heart, and a significant increase in cell apoptosis. Inactivation of p53 could rescue the early defects observed in esf1 mutants, indicating that increased cell death and defects observed in esf1 mutants was mediated via up-regulated p53 signaling pathways. In this proposal, we use zebrafish, an excellent model system in development research because of transparent embryos and in vitro development, to explore the role of esf1. Combining gene overexpression, loss of function and gain of function, Cas9 gene editing with cell culture in vitro, we will investigate the function of esf1 in early development, and how it interact with p53 signaling pathways and affect ribosome biogenesis. This study will uncover the mechanism how p53 is regulated in vivo by esf1, and ultimately provide the data for the zebrafish as a model organism in investing the functions of nucleolar proteins.