Adult stem cell activity in naked mole rats for long-term tissue maintenance.

The naked mole rat (NMR), Heterocephalus glaber, the longest-living rodent, provides a unique opportunity to explore how evolution has shaped adult stem cell (ASC) activity and tissue function with increasing lifespan. Using cumulative BrdU labelling and a quantitative imaging approach to track intestinal ASCs (Lgr5) in their native in vivo state, we find an expanded pool of Lgr5 cells in NMRs, and these cells specifically at the crypt base (Lgr5) exhibit slower division rates compared to those in short-lived mice but have a similar turnover as human LGR5 cells. Instead of entering quiescence (G0), NMR Lgr5 cells reduce their division rates by prolonging arrest in the G1 and/or G2 phases of the cell cycle.