SYNCHRONIZATION OF THE CYTOPLASMATIC AND THE NUCLEAR MATURATION OF OOCYTES <i>IN VITRO</i>

摘要

The present invention relates to a method for in vitro maturation of oocytes comprising the steps of: (a) culturing one or more GV oocytes in a culture medium, the culture medium comprising a nuclear maturation inhibiting substance and comprising one or more gonadotropins and/or one or more growth factors, the culturing taking place for a time period sufficient for cytoplasmatic maturation to occur; (b) washing the GV oocytes of step (a) to remove the nuclear maturation inhibiting substance; (c) culturing the washed oocytes of step (b) in a culture medium comprising one or more gonadotropins and/or one or more growth factors and/or MAS for a time period sufficient for nuclear maturation. The invention also relates to an oocyte culture medium comprising a nuclear maturation inhibiting substance and comprising one or more gonadotropins and/or one or more growth factors. The nuclear maturation inhibiting substance may be a MAS antagonist or an FF-MAS synthesis inhibitor, preferably a cytochrome P450 Panosterol 14 alpha -demethylase (P45014DM) inhibitor e.g. ketoconazole or 22-hydroxycholesterol. The one or more gonadotropins and/or one or more growth factors are preferably a combination of EGF and FSH and/or LH. The invention also relates to the use of a nuclear maturation inhibiting substance and one or more gonadotropins and/or one or more growth factors as described above for the preparation of a cell culture medium for in vitro maturation of oocytes.