P-127: The Effect of Supplementation of In Vitro Culture Medium with FGF2 on Ovine Embryo Development

Background: Fibroblast growth factors are a great family of growth factors that exert variety of functions in vertebrates including cell growth, survival, differentiation and migration. FGFRs are transmembrane tyrosine kinase receptors transmitting FGF signals. Four types of FGFRs (1/2/3/4) exist in vertebrates. FGF2 is one of the FGFs detected in bovine and ovine uterus flushes, supposing that it has effects on embryo development. Materials and Methods: In vitro produced ovine embryos via IVF were removed at different developmental stages (zygote, 2-4cell, 8-16cell, morula, and blastocyst) from day 1 to day 7 and positioned in RLT for investigation of FGFRs expression pattern by Real- Time PCR. In the case of FGF2 treatment effect, from day1, embryos were divided into two groups (control or 500ng/ml FGF2) in serumfree conditions. FGF2 was present in treatment group medium whole days and developmental rate were assessed during development until day8. Finally, expanded and hatched blastocysts differentially stained and cell numbers recorded by using fluorescence microscope. Results: According to our data all four types of FGFRs evinced dominant expression at morula stage while in the other stages FGFRs expression were in low levels. FGF2 supplementation did not significantly change the blastocyst formation rate and total cell numbers in FGF2 supplemented group compared to the control until day8. even though FGFRs were present in ovine embryos, their expression were in low levels except in morula. It is unclear whether FGFRs are in adequate levels to transduce FGF2 signals in ovine embryos. However, it does not seem that FGF2 exerts any proliferative or developmentally amending effect on ovine embryos up to day 8, according to our data. It is not known whether proliferative respond to FGF2 will appear from hatched blastocyst stage onward, one in which high proliferation rates prevail. Conclusion: We found neither a prominent effect of FGF2 on blastocyst formation rate nor proliferation in ovine embryos up to day 8 post fertilization.