Dong Zhangji, Chen Xu, Li Yuanyuan, Zhuo Run, Lai Xiaona, Liu Mei
Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.
Front Cell Dev Biol. 2021 Jan 18;8:593234. doi: 10.3389/fcell.2020.593234. eCollection 2020.
Previously, () and its family members () and () were found to be highly expressed during zebrafish brain development, suggesting their functions in the nervous system. In this study, we report the effects of loss-of-function of these genes on development. We designed and identified single-guide RNAs targeted to generate , and mutants and then observed the overall morphological and behavioral changes. Our findings showed that while and null mutants displayed no significant defects, null zebrafish mutants displayed pericardial edema, reduced heart rate, and smaller eyes; null mutants responded to the light-darkness shift with a lower swimming velocity. mRNAs were identified in vascular endothelial cells by hybridization and re-analysis of an online dataset of single-cell RNAseq results. Finally, we used morpholino oligonucleotides to confirm that knockdown resulted in severe heart edema, which was caused by abnormal vascular branching. The zebrafish morphants also showed longer axonal length and more branches of caudal primary neurons. Taken together, we summarize that Fignl2 functions on cellular branches in endothelial cells and neurons. This study reported for the first time that the microtubule-severing protein Fignl2 contributes to cell branching during development.
此前，（）及其家族成员（）和（）被发现在斑马鱼大脑发育过程中高度表达，表明它们在神经系统中发挥作用。在本研究中，我们报告了这些基因功能丧失对发育的影响。我们设计并鉴定了靶向产生、和突变体的单向导RNA，然后观察整体形态和行为变化。我们的研究结果表明，虽然和基因敲除突变体没有表现出明显缺陷，但基因敲除的斑马鱼突变体表现出心包水肿、心率降低和眼睛变小；基因敲除突变体在明暗转换时游泳速度较低。通过对单细胞RNA测序结果的在线数据集进行杂交和重新分析，在血管内皮细胞中鉴定出了mRNA。最后，我们使用吗啉代寡核苷酸证实，基因敲低导致严重的心包水肿，这是由异常的血管分支引起的。斑马鱼基因敲降胚胎还表现出尾初级神经元的轴突长度更长、分支更多。综上所述，我们总结出Fignl2在内皮细胞和神经元的细胞分支上发挥作用。本研究首次报道微管切断蛋白Fignl2在发育过程中有助于细胞分支。
