Oocyte selection: a tale of individualism, dominance and sacrifice

Oocyte development is a fierce competitive process in which only a small fraction of germ cells survives massive waves of cell death to become a fertilizable egg. Using an ex vivo 4D imaging system, Zhang and colleagues discovered that individual oocytes actively move, extend filopodia-like protrusions, and engulf the debris of their dying neighbors to fuel their own growth (Zhang et al, 2025a). These findings reveal a previously unrecognized, phagocytosis-driven mechanism of oocyte selection that shapes the ovarian reserve. New research in EMBO Reports reveals a phagocytosis-driven mechanism of oocyte selection in mouse.