Multicellular rosettes are transient epithelial structures that serve as intermediates during diverse organ formation. We have identified a unique contributor to rosette formation in zebrafish Kupffer’s vesicle (KV) that requires cell division, specifically the final stage of mitosis termed abscission. KV utilizes a rosette as a prerequisite before forming a lumen surrounded by ciliated epithelial cells. Our studies identify that KV-destined cells remain interconnected by cytokinetic bridges that position at the rosette’s center. These bridges act as a landmark for directed Rab11 vesicle motility to deliver an essential cargo for lumen formation, CFTR (cystic fibrosis transmembrane conductance regulator). Here we report that premature bridge cleavage through laser ablation or inhibiting abscission using optogenetic clustering of Rab11 result in disrupted lumen formation. We present a model in which KV mitotic cells strategically place their cytokinetic bridges at the rosette center, where Rab11-associated vesicles transport CFTR to aid in lumen establishment.

多细胞玫瑰花结是短暂的上皮结构，在不同器官形成过程中充当中间体。我们已经确定了斑马鱼库普弗囊泡 (KV) 中玫瑰花结形成的独特贡献者，它需要细胞分裂，特别是有丝分裂的最后阶段（称为脱落）。 KV 在形成被纤毛上皮细胞包围的管腔之前利用玫瑰花结作为先决条件。我们的研究发现，KV 定向细胞仍然通过位于玫瑰花结中心的细胞因子桥相互连接。这些桥充当定向 Rab11 囊泡运动的里程碑，为管腔形成提供必需的货物 CFTR（囊性纤维化跨膜电导调节剂）。在此，我们报告通过激光烧蚀或使用 Rab11 的光遗传学聚类抑制脱落而导致桥过早裂解，从而导致管腔形成中断。我们提出了一个模型，其中 KV 有丝分裂细胞战略性地将其细胞因子桥放置在玫瑰花结中心，Rab11 相关囊泡在此运输 CFTR 以帮助管腔建立。