Abstract

The cryopreservation of animal and human oocytes has potential for the development of Assisted Reproductive Technology (ART), especially as bank of oocytes. One of the techniques used for oocyte cryopreservation is vitrification procedure to avoid the critical temperature and reduce cell damage caused by the formation of ice crystals on oocyte cryopreservation. Although Oocyte vitrification method is practical, applicable, efficient, inexpensive, and simple, but still needs further research because of the negative effects caused by temperature stress. Extreme temperature due to temperature changes from hot - cold - hot in the series of vitrification processes need to be aware of damage to the structure of cell proteins and DNA. Extreme temperature will cause stress oocytes. Stress cells increase the need of Heat Shock Protein 70 as a stress protein. The response of Heat Shock Protein 70 (HSP70) inductive or synthesize is thought to be protective mechanism of the cells to stress condition such as an extreme change of temperature. Assessment needs to be done regarding the role of HSP70 in cell protection against the extreme changes of temperature during oocyte vitrification by adding supplementation of HSP70 into the cryoprotectant vitrification. In conclusion, the HSP70 has a a pivotal role in cell protection against stress cells during oocyte vitrification. Additionally, fresh oocytes, in vitro maturated oocytes, and post-warming oocytes exhibit the HSP70 and Cytochrome c expression. Supplementation of HSP70 into vitrification medium expected useful to suppressed the activation of caspase 3, resulted in maintain the viability of oocytes during vitrification and decreased the incidence of apoptosis after warming.

Key words: Apoptosis; Caspase 3; Cytochrome c; In vitro; Oocyte maturation; Endangered species; Extinction risk.