An abundant myeloid progenitor shapes neonatal hematopoiesis of naked mole-rats

The naked mole-rat became a significant animal model for its exceptional longevity and resistance mechanisms to cancers, however the developmental properties of their native stem and progenitor compartments are poorly understood. Here we report a high frequency bone marrow progenitor exclusively present in neonatal animals. The heterotypic developmental stage was marked by an immunophenotype resembling adult naked mole-rat CMP-like progenitors with mature neutrophilic Thy1.1-antigen levels and showed a clear differentiation bias and transcriptome signature towards myelopoiesis. Importantly, myeloid progenitors overexpressed both CXCL12 and its alternative receptor CXCR7, thereby abrogating their homing capacity and produced multiple secreted matrix components related to neonatal bone marrow niche formation. These results indicate a transient ontogenic cell stage during postnatal hematopoiesis unique to naked mole-rats and further advances our understanding of the developmental steps involved in creating the regenerative cell pool and its environment in a long-lived species.