The accessibility and transparency of the cornea permit robust stem cell labeling and in vivo cell fate mapping. Limbal epithelial stem cells (LSCs) that renew the cornea are traditionally viewed as rare, slow-cycling cells that follow deterministic rules dictating their self-renewal or differentiation. Here, we combined single-cell RNA sequencing and advanced quantitative lineage tracing for in-depth analysis of the murine limbal epithelium. These analysis revealed the co-existence of two LSC populations localized in separate and well-defined sub-compartments, termed the “outer” and “inner” limbus. The primitive population of quiescent outer LSCs participates in wound healing and boundary formation, and these cells are regulated by T cells, which serve as a niche. In contrast, the inner peri-corneal limbus hosts active LSCs that maintain corneal epithelial homeostasis. Quantitative analyses suggest that LSC populations are abundant, following stochastic rules and neutral drift dynamics. Together these results demonstrate that discrete LSC populations mediate corneal homeostasis and regeneration.

角膜的可及性和透明度允许强大的干细胞标记和体内细胞命运图谱。传统上，更新角膜的角膜缘上皮干细胞（LSC）被视为罕见的、缓慢循环的细胞，遵循决定其自我更新或分化的确定性规则。在这里，我们结合单细胞 RNA 测序和先进的定量谱系追踪来深入分析小鼠角膜缘上皮。这些分析揭示了两个 LSC 群体的共存，它们位于独立且定义明确的子区室中，称为“外部”和“内部”边缘。静态外部 LSC 的原始群体参与伤口愈合和边界形成，这些细胞受到 T 细胞的调节，T 细胞充当生态位。相比之下，角膜周围角膜缘内有活跃的 LSC，可维持角膜上皮稳态。定量分析表明，LSC 种群数量丰富，遵循随机规则和中性漂移动态。这些结果共同表明，离散的 LSC 群体介导角膜稳态和再生。