Comparison of the Effect of Cytochalasin B and Paclitaxel (Taxol(superscript TM)) on Cryopreservation of ICR Mouse Oocytes

Abstract

Objective: To investigate the benefits of the cytoskeleton stabilizers paclitaxel and cytochalasin B (CCB) in the oocyte vitrification procedure. Materials and Methods: ICR mice aged 4-6 weeks were superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin. In Experiment 1, all retrieved eggs were randomly assigned to group A or B for the cumulus cell effect test and went through the vitrification protocol. In Experiment 2, the oocytes were allocated randomly to one of two subgroups for the cytoskeleton stabilizer tests: subgroup B, paclitaxel, and subgroup C, CCB. Group B in Experiment 1 served as the control (i.e. subgroup A) in Experiment 2. Results: In Experiment 1, denuded oocytes had a higher fertilization rate after thawing than cumulus-enclosed ones. Accordingly, cumulus-free oocytes were chosen for Experiment 2. In Experiment 2, there were significant differences in post-thaw survival rates and fertilization rates between subgroups A and B. There was also a significant difference in fertilization rates between subgroups A and C. However, there were no differences in cleavage rates of 2 4- and 6 8-cell embryos between the subgroups. Conclusion: Cumulus-free oocytes have greater developmental competence than cumulus-enclosed ones. Adding paclitaxel significantly improves the survival rate and fertilization rates of post-thaw cumulus-free ICR mouse oocytes. The addition of CCB also improves the fertilization rate of post-thaw oocytes.