[Evolution of cytoplasmic and membrane parameters during human oocyte maturation]

Human oocyte cytometry was studied during a program of Subzonal Insemination. Oocytes with a diameter over 108 microns presented higher fusiogenic ability than others. Independently of nuclear maturational criteria, the ooplasma growth appears as an important factor of oocyte maturity. Human oocyte plasma membrane protein pattern was assessed using biotinylation technique, western Blot and chemoluminescence (ECL) on 2 days old unfertilized oocytes. The total membrane protein content decreases dramatically from germinal vesicle to metaphase 2 stage oocytes with a relative over expression of the 71 kD. It represents 30% of the total protein content of the mature oocyte membrane. The protein profile, assessed on single oocytes, showed a polymorphism including for oocytes coming from the same cohort. Its functional importance is currently investigated.