Previously, fidgetin (fign) and its family members fidgetin-like 1 (fignl1) and fidgetin-like 2 (fignl2) 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 fign, fignl1, and fignl2 mutants and then observed the overall morphological and behavioral changes. Our findings showed that while fign and fignl1 null mutants displayed no significant defects, fignl2 null zebrafish mutants displayed pericardial edema, reduced heart rate, and smaller eyes; fignl2 null mutants responded to the light-darkness shift with a lower swimming velocity. fignl2 mRNAs were identified in vascular endothelial cells by in situ hybridization and re-analysis of an online dataset of single-cell RNAseq results. Finally, we used morpholino oligonucleotides to confirm that fignl2 knockdown resulted in severe heart edema, which was caused by abnormal vascular branching. The zebrafish fignl2 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.

先前， 胃泌素 （菲根）及其家庭成员 胃泌素样1 （图1）和 胃泌素样2 （图2）在斑马鱼的大脑发育过程中被高度表达，表明它们在神经系统中的功能。在这项研究中，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生成的单向导RNA菲格和 图2然后观察突变体的整体形态和行为变化。我们的发现表明菲根 和 图1 空突变体无明显缺陷， 图2 空的斑马鱼突变体表现出心包水肿，心率降低和眼睛变小； 图2 空突变体以较低的游泳速度响应明暗变化。 图2 通过鉴定血管内皮细胞中的mRNA。 原位杂交和单细胞RNAseq结果在线数据集的重新分析。最后，我们使用吗啉代寡核苷酸来确认图2击倒导致严重的水肿，这是由异常的血管分支引起的。斑马鱼图2morph变体还显示出更长的轴突长度和更多的尾部初级神经元分支。综上，我们总结出Fignl2在内皮细胞和神经元的细胞分支上起作用。该研究首次报道了微管分离蛋白Fignl2在发育过程中有助于细胞分支。