The functions of cilia—antenna-like organelles associated with a spectrum of disease states—are poorly understood, particularly in human cells. Here we show that human pluripotent stem cells (hPSCs) edited via CRISPR to knock out the kinesin-2 subunits KIF3A or KIF3B can be used to model ciliopathy phenotypes and to reveal ciliary functions at the tissue scale. KIF3A^–/– and KIF3B^–/– hPSCs lacked cilia, yet remained robustly self-renewing and pluripotent. Tissues and organoids derived from these hPSCs displayed phenotypes that recapitulated defective neurogenesis and nephrogenesis, polycystic kidney disease (PKD) and other features of the ciliopathy spectrum. We also show that human cilia mediate a critical switch in hedgehog signalling during organoid differentiation, and that they constitutively release extracellular vesicles containing signalling molecules associated with ciliopathy phenotypes. The capacity of KIF3A^–/– and KIF3B^–/– hPSCs to reveal endogenous mechanisms underlying complex ciliary phenotypes may facilitate the discovery of candidate therapeutics.

纤毛（与一系列疾病状态相关的类似天线的细胞器）的功能人们知之甚少，特别是在人类细胞中。在这里，我们展示了通过 CRISPR 编辑的人类多能干细胞 (hPSC) 敲除驱动蛋白 2 亚基 KIF3A 或 KIF3B，可用于模拟纤毛病表型并在组织尺度上揭示纤毛功能。KIF3A ^–/–和KIF3B ^–/– hPSC 缺乏纤毛，但仍具有强大的自我更新能力和多能性。来自这些 hPSC 的组织和类器官表现出的表型概括了神经发生和肾发生缺陷、多囊肾病 (PKD) 和纤毛病谱系的其他特征。我们还表明，人类纤毛在类器官分化过程中介导刺猬信号传导的关键转换，并且它们组成性地释放含有与纤毛病表型相关的信号分子的细胞外囊泡。KIF3A ^–/–和KIF3B ^–/– hPSC 揭示复杂睫状体表型背后的内源性机制的能力可能有助于发现候选疗法。