High efficacy of fibroblast and hepatocyte growth factors on the in vitro blastocyst production of post-thaw mouse two-cell embryo: The cryotop method
There is great need to improve our understanding of what increases an embryo’s development potential, after vitrification-thawing processes. For this subject, 358 two-cell stage embryos were collected from oviduct of pregnant two-day old mice and vitrified. After thawing, embryos were cultured in Tyrode's (T6) medium supplemented with different doses of fibroblast growth factor (FGF; 0, 10, 20, 50 and 100 ng/ml) and hepatocyte growth factor (HGF; 0, 10, 20, 50 and 100 ng/ml) until the blastocyst stage. To determine quality of blastocysts, blastocysts were stained with hoechst and propidium iodide. After culture for 24 h, 92.65% of treated embryos with 20 ng/ml of FGF had higher (P<0.05) survival rate in comparison to the control group (84%). Blastocyst embryo formation rate were 79.43% (P< 0.01), and 67.46% (P< 0.05) in the treated groups with 20 ng/ml of FGF and 20 ng/ml of HGF, respectively, which were significantly different from the control (56%). In the treatment group with 20 ng/ml of FGF, blastocysts with >64 cells had a significantly higher inner cell mass (ICM) in comparison to the control group (P< 0.01). In conclusion, in this experiment, addition of growth factors in the culture had favorable effects on post-thawed cleavage of vitrified 2-cell embryos and blastocyst quality.
Key words: Blastocyst quality, growth factors, preimplantation development, vitrification.