A detailed understanding of intestinal stem cell (ISC) self-renewal and differentiation is required to treat chronic intestinal diseases. However, the different models of ISC lineage hierarchy^1,2,3,4,5,6 and segregation^{7,8,9,10,11,12} are subject to debate. Here, we have discovered non-canonical Wnt/planar cell polarity (PCP)-activated ISCs that are primed towards the enteroendocrine or Paneth cell lineage. Strikingly, integration of time-resolved lineage labelling with single-cell gene expression analysis revealed that both lineages are directly recruited from ISCs via unipotent transition states, challenging the existence of formerly predicted bi- or multipotent secretory progenitors^{7,8,9,10,11,12}. Transitory cells that mature into Paneth cells are quiescent and express both stem cell and secretory lineage genes, indicating that these cells are the previously described Lgr5⁺ label-retaining cells⁷. Finally, Wnt/PCP-activated Lgr5⁺ ISCs are molecularly indistinguishable from Wnt/β-catenin-activated Lgr5⁺ ISCs, suggesting that lineage priming and cell-cycle exit is triggered at the post-transcriptional level by polarity cues and a switch from canonical to non-canonical Wnt/PCP signalling. Taken together, we redefine the mechanisms underlying ISC lineage hierarchy and identify the Wnt/PCP pathway as a new niche signal preceding lateral inhibition in ISC lineage priming and segregation.

治疗慢性肠道疾病需要详细了解肠道干细胞 (ISC) 的自我更新和分化。然而，ISC 血统等级^{1、2、3、4、5、6}和隔离^{7、8、9、10、11、12}的不同模型仍存在争议。在这里，我们发现了非经典 Wnt/平面细胞极性 (PCP) 激活的 ISC，这些 ISC 被引导至肠内分泌或潘氏细胞谱系。引人注目的是，时间分辨谱系标记与单细胞基因表达分析的整合表明，这两种谱系都是通过单能过渡状态直接从 ISC 募集的，挑战了以前预测的双能或多能分泌祖细胞的存在^{7,8,9,10， 11,12}. 成熟为潘氏细胞的过渡细胞处于静止状态并表达干细胞和分泌谱系基因，这表明这些细胞是先前描述的 Lgr5 ⁺标记保留细胞⁷。最后，Wnt/PCP 激活的 Lgr5 ⁺ ISC 在分子上与 Wnt/β-连环蛋白激活的 Lgr5 + ISC 在分子上无法区分^，这表明谱系启动和细胞周期退出是在转录后水平上由极性线索和从规范的转换触发的。到非规范 Wnt/PCP 信令。总之，我们重新定义了 ISC 谱系层次结构的机制，并将 Wnt/PCP 通路确定为 ISC 谱系启动和分离中侧抑制之前的新生态位信号。