Abstract

Heat-shock protein 70 (HSP70) plays a crucial role as intracellular cytoprotectant and molecular chaperone. A phenomenon of heat stress (HS) leads to production of these proteins that could be beneficial to cells during cryopreservation, which is also a stressful process for the cell. This study aimed to evaluate the protective effect of exposure of bovine oocytes to moderate HS during in vitro maturation (IVM) prior vitrification. First, oocytes were subjected to HS (41.5°C for 1hr) at 0, 4, 8, 12 or 16 of IVM. Oocytes in vitro matured for 20hr served as control group. Presence of HSP70 was detected at 20hr by immunofluorescence. HSP70 expression was significantly higher when oocytes were subjected to HS at 8hr of IVM. Next, oocytes were distributed into four groups: Control: IVM oocytes; VIT: oocytes vitrified/warmed at 20hr of IVM; HS: oocytes subjected to HS at 8hr of IVM; HS-VIT: oocytes subjected to HS at 8hr of IVM and vitrified/warmed at 20hr of IVM. Oocytes were fertilized at 24hr of IVM, and cleavage and blastocyst yield were assessed. No significant differences were observed among treatments when cleavage rate was evaluated. However, fresh control and HS oocytes resulted in a significantly higher (p<.05) blastocyst rate when compared to VIT and HS-VIT groups, although no significant differences within fresh or vitrified groups were observed. In conclusion, HS did not have a negative impact on the oocyte competence but HS applied before vitrification, offered no benefits for embryo development.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.