THE EFFECT OF HSP60 ON FERTILIZATION AND PRE-IMPLANTATION EMBRYO DEVELOPMENT IN MICE: AN IN VITRO STUDY

Context. Heat Shock Protein 60 (HSP60) is a chaperone protein which is involved in proteins transfer and re-folding of proteins. Objective. Importance of HSP60 in sperm capacitation and facility of sperm-oocyte membrane binding was confirmed, therefore in this study the effect of HSP60 on the rate of in vitro fertilization and the cleavage rate in mouse embryo was investigated. Design. Ten male mice and twenty five female mice were involved to collect sperms and oocytes required for this study. Subjects and Methods. Sperms were collected from the epididymis of male mouse and oocytes were collected from the oviduct of female mouse following ovarian hyperstimulation. Then, capacitated sperms and oocytes were placed together in fertilization medium in four groups in the presence of different concentrations of HSP60 (10, 50 and 100 ng/mL) and in the absence of HSP60. After calculation of the fertilization rate, zygotes were transformed into the other medium for development and the cleavage rate was monitored to blastocyst stage. Results. There was not a significant difference in the rate of fertilization between 10 ng/mL HSP60 group and the control group. The rate of fertilization and two-cell embryo development decreased significantly (P <= 0.05) in 100 ng/mL HSP60 compared to other experimental and control groups. Further, the rate of two-cell embryo development increased significantly (P <= 0.05) in 10 ng/mL HSP60 compared to other experimental and control groups. Conclusions. The present study demonstrated that HSP60 in low dose had a positive effect on two-cell embryo development, however it did not have any significant effect on the fertilization rate. Conversely, HSP60 had adverse effects on the fertilization and cleavage rates at higher doses.