P-103: Connection of The G6PDH Activity on Fertilization and Developmental Competency in The Bovine

Background: This study was conducted in order to determine whether BCB staining performed on immature bovine oocytes to assess G6pdhlevel has an impact on ivf/ivp technology in bovine embryos. Both spermatozoa and oocytes metabolize glucose through the pentose phosphate pathway (PPP), and NADPH appears necessary for gamete fusion. Activity of glucose 6-phosphate dehydrogenase (G6PDH), the key enzyme of the PPP. have a high in growing oocytes, while grown oocytes have low G6PDH activity. In additional it seems grown oocyte have more ability to developmentally competency, have the more rate of Sperm-oocyte fusion too. Materials and Methods: Immature compact cumulusoocyte complexes were stained with brilliant cresyl blue (BCB), used to indicate G6PDH activity. Based on their colouration, oocytes were divided into BCB (-) (colourless cytoplasm, high G6PDH activity) and BCB (+) (coloured cytoplasm, low G6PDH activity). The MII oocytes and complex sperm oocyte 16-18 hour post insemination were stained with DAPI to evaluate percentage of maturation and fusion of sperm and oocytes, and other oocytes were then matured, fertilized, and cultured in vitro for 7 days. Fertilization events following IVF and subsequent pre-implantation embryo development were evaluated. Embryo quality were assessed with deformational staining. Results: The rate of mature oocytes at the MII stage differed significantly between BCB+ (85.5%) and BCB- (67.8%). Spermoocyte fusion rate were also significantly higher in the BCB+ group compared with the BCB- group The percentage of blastocyst development was higher in BCB+ and was significantly different between BCB+ (39.25 ± 2.4) and BCB- (20 ± 7.48) oocytes. Total cell number, TE cell number, ICM cell number: TE ratio of blastocysts were significantly higher in the BCB+ group compared with the BCB- group. Conclusion: These results confirmed that the staining of bovine cumulus oocyte complexes with BCB before in vitro maturation may be used to select developmentally competent oocytes for IVF.