Table 1.
The survival rate and embryo development of vitrified-warmed germinal vesicle stage (GV) oocytes after parthenogenetic activation.
Table 2.
Fertilization and embryo development of vitrified-warmed germinal vesicle stage (GV) oocytes after in vitro fertilization.
Fig 1.
Delayed initiation of germinal vesicle breakdown (GVBD) and meiotic maturation in the oocytes treated with forskolin (FSK) and 3-isobutyl-1-methylxanthine (IBMX).
A) The GVBD rate at 0, 0.5, 1, 2, 4, 8, and 12 h in IVM culture. Delayed GVBD was observed in the FSK and IBMX groups. B) The maturation rate at 22, 26, and 30 h after the initiation of IVM culture. Although delay in oocyte maturation occurred in the FSK and IBMX groups, the maturation rates at 30 h were comparable to those in the control groups. Error bars represent standard error of the mean. Bars labeled with different letters show significant differences (P < 0.05).
Fig 2.
Transient upregulation of cAMP levels in vitrified-warmed germinal vesicle-stage (GV) oocytes treated with forskolin (FSK) or 3-isobutyl-1-methylxanthine (IBMX).
A) Effect of FSK and IBMX on the level of intraoocyte cAMP during IVM culture. The intraoocyte cAMP level was reduced by vitrification prior to IVM culture, and this low cAMP level could be increased back to normal by supplementation of the IVM medium with FSK or IBMX. B) Level of intraoocyte cAMP at the initiation of culture (Group 1) or after culturing for 0.5 h (Group 2), immersion of vitrification/warming solution (Group 3), vitrification and warming (Group 4), vitrification and warming in vitrification/warming solution supplemented with FSK, IBMX or the combination of FSK and IBMX (Group 5–7). The decline in the cAMP level was induced by the vitrification procedure. Non-vitrification, GV oocytes cultured in mTCM199/20%SSS for 0.5 h; immersion, GV oocytes immersed in the vitrification/warming solution; vitrification, GV oocytes vitrified and warmed. Error bars represent standard error of the mean. Bars labeled with different letters show significant differences (P < 0.05).
Fig 3.
Delayed MPF elevation induced by the treatment of vitrified-warmed GV oocytes with forskolin (FSK) or 3-isobutyl-1-methylxanthine (IBMX).
Effect of FSK and IBMX on intraoocyte MPF activity during IVM culture. Low MPF activity was observed in the vitrified-warmed control group at the end of IVM culture, whereas the MPF activity of the vitrified-warmed FSK and IBMX groups was comparable to that of the corresponding fresh groups. Error bars represent standard error of the mean. Bars labeled with different letters show significant differences (P < 0.05).