Purpose To associate the glucose-6-phosphate dehydrogenase (G6PDH) activity in
immature goat oocyte with intracellular glutathione (GSH) content, developmental
competence after parthenogenetic activation and relative abundance of Bax and Bcl-2
genes transcripts using .
Methods Goat oocytes were exposed to brilliant cresyl blue (BCB) staining and
categorized into BCB+ (blue cytoplasm) and BCB− (colorless cytoplasm) groups. A
group of oocytes were not exposed to BCB stain and was considered as a control.
After maturation in vitro, a group of oocytes were used for determination of nuclear
status and intracellular GSH content and another group were subjected to
parthenogenetic activation followed by in vitro embryo culture.
Results We found that BCB+ oocytes yielded a significantly higher maturation rate than
the BCB− and control oocytes. Moreover, BCB+ oocytes showed increased in
intracellular level of GSH than BCB− and control oocytes. Furthermore, BCB+ oocytes
produced more blastocysts than BCB− and control oocytes. The expression of antiapoptotic
gene Bcl-2 and pro-apoptotic gene Bax in mature oocyte, their surrounding
cumulus cells and blastocyst was affected by BCB staining test.
Conclusions These results strongly suggest that BCB+ oocytes have a higher meiotic
and cytoplasmic maturity (as determined by intracellular GSH content), and that BCB
staining can be used to select developmentally competent oocytes for in vitro embryo