Association of heat shock protein 90 with the developmental competence of immature oocytes following Cryotop and solid surface vitrification in XXXX ( @entity25762 ).

@entity12432 @entity25762
UNASSIGNED: The correlation between the 90kDa heat-shock protein (HSP90) and the developmental competence of @entity25762 ( @entity25762 ) oocytes following the process of vitrification has not been studied clearly. In the present study, we compare the efficacies of Cryotop (CT) and solid surface vitrification ( @entity12432 ) methods for the cryopreservation of immature @entity25762 oocytes. @entity25762 cumulus oocyte complexes were randomly allocated into three groups: (1) controls, (2) CT vitrification, and (3) @entity12432 vitrification. Oocytes were vitrified and in vitro maturated and fertilized. The percentages of nuclear maturation and in vitro development were evaluated. The vitrified-warmed oocytes were evaluated for mRNA and protein expression levels of HSP90 using quantitative real-time PCR and western blotting at various stages: matured oocytes, 2-8cells embryos and blastocysts. No difference was found in the percentages of nuclear maturation, cleavage or blastocyst in the two vitrified groups; however, the rates of maturation were significantly lower than those in the control group. Among the three groups, the maturation rates in CT: 51.14  0.86% and @entity12432 : 50.82  1.34% were less than those of the controls: 69.65  1.13%; the cleavage rates in CT: 39.16  1.01% and @entity12432 : 39.08  0.92%, were less than those of the controls: 58.14  0.76%; but the blastocysts rates and total cell number in the blastocysts were similar: CT: 32.20  0.73% and 104.6  3.72; @entity12432 : 32.35  0.81% and 102.4  1.34; and controls: 34.38  1.32% and 103.8  4.13, respectively. The HSP90 expression level in the matured oocytes and 2-8cell embryos of the control group was significantly higher than that in the two vitrified groups; there was not significant difference in the blastocysts in the three groups. We thus conclude that CT and @entity12432 perform equally in the vitrification of immature @entity25762 oocytes during the process of cryopreservation, and their influence on oocytes mainly occured from the maturation to cleavage stages. The HSP90 levels in the blastocysts of the vitrified groups increased is associated with the developmental competence of the embryo.
