Verlhac, Terret and colleagues report that softening of the mouse oocyte cortex during meiosis I is needed for spindle migration and positioning. They show that Mos/mAPK signalling triggers myosin II exclusion from the cortex and an Arp2/3-dependent cortical F-actin thickening that contributes to cortical softening.
- Agathe Chaigne
- Clément Campillo
- Marie-Emilie Terret
