Abstract
This study was undertaken to evaluate the effect of follicular fluid supplementation on the oocyte in vitro maturation and early embryonic development after in vitro fertilization. Sheep follicular fluid (SFF) was collected from different ovaries and supplemented to the in vitro maturation (IVM) media with proportions 0%, 10%, 20% and 40%. Oocyte maturation was assessed in different treatments and then cumulus-oocyte complexes were used for in vitro fertilization. Relative quantitative expression of mRNA transcripts related to apoptosis (Bax and Bcl-2), embryo development (LAMA1, IL-6 and FGF4) and stress (HSPB1) were examined. The results showed that 10% and 20% SFF supplementation exerted no effect on maturation and cleavage percentage whereas 40% SFF supplementation significantly decreased maturation and cleavage. SFF supplemented at 10% concentration showed a significant increase in blastocyst development when compared with other groups. Gene expression analysis revealed a significant increase in BAX expression in groups supplemented with SFF 20% and 40%, whereas the expression of BCL-2 was significantly increased only in the 40% SFF supplemented group. The ratio of Bax to Bcl-2 was significantly increased in the embryos derived from oocytes matured in 20% and 40% SFF supplemented media. HSPB1 expression was significantly increased in group matured in 20% SFF. The relative expression of IL-6, LAMA1 and FGF4 genes did not show any difference between groups. In conclusion, IVM medium supplemented with 10% SFF showed the best rate of blastocyst development.