Sperm Production-Line Maintenance

摘要

The average man makes upwards of 1500 sperm per heartbeat.rnSuch a feat requires a robust stem cell system. Using mice, Nakagawa et al. (p. 62, published online 18 March) shed light on some of the properties of the murine germline stem cell system that contribute to its robustness. During steady-state spermatogenesis, the majority of the stem cell population lies within a subset of cells called type A spermatogonia. However, during regeneration (for example, during recovery of the stem cell pool after drug exposure) the system in essence hijacks early-differentiating cells back into the stem cell compartment. Lineage analysis and live-imaging also suggests that during sperm production there is more than one path from a stem cell to differentiation.