Effect of prematuration and maturation with fibroblast growth factor 10 (FGF10) on in vitro development of bovine oocytes.

In an attempt to improve in vitro embryo production, we investigated the effect of FGF10 and 0.1 mM of cilostamide, cAMP modulator, during in vitro prematuration (PIVM) and in vitro maturation (IVM) on the developmental capacity of bovine oocytes. Five treatments (T) were used as follows: T1) IVM (control): COCs were matured for 22 h; T2) PIVM/IVM: COCs were submitted to 22 h of PIVM and 22 h of IVM; T3) PIVM + FGF10/IVM: COCs were submitted to PIVM for 22 h in the presence of FGF10 and matured for 22 h; T4) PIVM/IVM + FGF10: COCs were submitted to PIVM for 22 h and matured for 22 h in the presence of FGF10; and T5) PIVM + FGF10/IVM + FGF10: COCs were submitted to 22 h of PIVM and 22 h of IVM, both in the presence of FGF10. COCs were evaluated for CC expansion and nucleus configuration at 0 h, 22 h of PIVM and 22 h after IVM. At those time points, CCs were used for expression analysis of PTGS2, TNFAIP6, PTX3, HAS2, CASP8, CASP3, SLC2A1, SLC2A3 and FGFR2 genes. Then, embryo production was evaluated on D2 for cleavage and at D6, D7 and D8 for embryo development. Embryo quality was measured by the speed of development and by expression of KRT8, PLAC8, CD9, PAG2, PAG2, HSPB1, MSH6 genes. The percentage of COC that remained at GV after 22 h PIVM was lower (P < 0.05) in the treated group than in the control group, regardless of the addition of FGF10. Nevertheless at 22 h of maturation, none of the treatments affected the final rate of MII oocytes. No expansion of CCs was observed during the PIVM period. After 22 h of maturation expansion was similar (P > 0.05) for all groups but they all had lower expansion (P < 0.05) than control group. Except for PTGS2 and SLC2A1 which were unchanged during PIVM, all other genes changed their expression during PIVM. When we evaluated the changes in gene expression during IVM on the different groups, we noted a change in the expression of four genes (PTGS2, CASP8, PTX3 and TNFAIP6). No differences (P > 0.05) in the cleavage and blastocyst rates at D6 were observed among treatment groups. However, the blastocyst rates at D7 were lower (P < 0.05) than the control groups in which FGF10 was present either during PIVM or during IVM. When the speed of embryo development was evaluated on D7, embryos from groups PIVM-IVM and PIVM - IVM + FGF10 developed faster than the other groups. However, at D8, the hatching rate was similar (P > 0.05) for all groups. Of all the analysed genes, only PLAC8 was shown to be overexpressed in PIVM/IVM + FGF10, and MSH6 was less expressed (P < 0.05) in PIVM + FGF10/IVM + FGF10 group when compared with the control. According to these findings, the PIVM of COCs in the presence of FGF10 affected the molecular profile and the expansion of CCs without affecting the nuclear maturation and embryo production rates. Although the presence of FGF10 changed the expression of genes related to embryo quality it did not show a great impact when added either or both during PIVM and IVM.

Bovine in vitro embryo production: the effects of fibroblast growth factor 10 (FGF10).

PURPOSE: In an attempt to improve in vitro embryo production, we investigated the effect of fibroblast growth factor 10 (FGF10) during in vitro maturation on the developmental capacity of bovine oocytes. MATERIAL AND METHODS: Cumulus-oocyte complexes (COCs) were aspirated from follicles of 3-8 mm diameter. After selection, the COCs were matured in medium with or without 0.5 ng/mL of FGF10. The effect of FGF10 during in vitro maturation (IVM) on nuclear maturation kinetics and expansion of the cumulus cells was investigated. Oocyte competence was assessed by the production and development speed of embryos and the relative expression of genes associated with embryo quality. RESULTS: FGF10 delayed the resumption of meiosis from 8 h onwards, but did not affect the percentage of oocytes reaching metaphase II, nor did it increase cumulus expansion at 22 h of maturation. We found no difference between treatments regarding embryo production, developmental speed, and gene expression. CONCLUSION: In conclusion, the presence of FGF10 during IVM had no effect on embryo production, developmental speed, and gene expression.