An integrated single-cell atlas of peripheral glia reveals progenitor-like states and enables cross-study mapping of dorsal root ganglia

Sensory neuron soma and non-neuronal cells in adult dorsal root ganglia (DRG) derive from multipotent neural crest cells. Satellite glial cells (SGCs), which surround neuronal soma, were suggested to retain developmental potential, but the precise molecular identity of progenitor cells in the adult DRG remains undefined. To address this question, we assembled a comprehensive single-cell transcriptomic atlas by integrating over 200,000 DRG and sciatic nerve transcriptomes across multiple studies and injury paradigms. High-resolution clustering resolved 26 cell types and demonstrated significant transcriptional heterogeneity within SGCs and Schwann cells, including repair and reactive sub-states. Crucially, we identified two distinct populations of progenitor cells that reflect different states in the progenitor trajectory. Functionally, progenitor cell numbers significantly increase after injury, and endothelin signaling regulates glial cell proliferation early in development. This integrated DRG and peripheral nerve cell atlas represents an essential resource for exploring new features of the peripheral nervous system.