Mouse MII oocytes were cryopreserved by open-pulled straw method.
The ROS levels and genes (Dcp1a, Dcp2, Hspa1a, Eif1ax, Pou5f1, Sox2) expression were changed.
After melatonin supplementation, the genes expressions were almost recovered to normal level.
Melatonin could increase the developmental potential of vitrified mouse MII oocytes.