Identification of renal stem cells in zebrafish.

Renal stem cells (RSC) hold great promise as kidney disease regenerative therapies. However, RSCs capable of regenerating de novo nephrons remain unidentified in vertebrates. Therefore, this study aimed to identify RSCs in zebrafish. Single-cell RNA sequencing revealed eya2, pax2a, and six2a as primary markers of zebrafish RSCs. Real-time imaging demonstrated that RSCs originated from eya2-positive mesenchymal cells. Notably, photoconversion-based lineage tracing and serial transplantation assays revealed a unique RSC renewal process, characterized by a differentiation-proliferation-dedifferentiation mode. This process generates nephrons and nascent RSCs concurrently. In addition, precise Wnt signaling is key for RSC renewal and differentiation balance and directly activates eya2 expression to initiate renewal. This discovery establishes a foundation for the advancement of stem cell therapies for kidney diseases.