Effect Of Vascu Lar Endothelial Growth Factor On In Vitro Development Of Pig Embryos

Previous studies have showed that vascular endothelial growth factor was related to the pre-implantational development of porcine embryos,but the results were not consistent,they were mainly because of culture medium containing serum and other unknown material on the early embryonic growth had a great interference.For the first time,the present study was designed to examine the effect of VEGF on pre-implantational development of porcine embryos by the chemically defined medium and apoptosis technology,expressing the real effect of the derived growth factors.The experiments and the results were as follows:Experiment 1: Effect of VEGF on the maturation development of porcine oocytes(granule cell layer wrap ≥ 3)and the pre-implantational development of porcine parthenogenetic embryos.VEGF at different concentrations(the control group: 0 ng/mL;the treatment groups: 5,25,50 ng/mL)was added into the defined mature medium.There was no significant difference in the porcine cumulus oocyte complexes diffusion,the maturation rate,the cleavage rate,the blastocyst rate,the total cell number,the apoptotic cell number or the apoptotic index.Experiment 2: On the basis of experiment 1,effect of VEGF on the maturation development of porcine oocytes(granule cell layer wrap ≤1)and the pre-implantational development of porcine parthenogenetic embryos.There was no significant difference in the nuclear maturation rate of porcine oocytes with cumulus cell attached.The maturation rate of 5 ng/mL group was significantly higher than that of the control group,the seventh day and the max blastocyst rate of 25 ng/mL groups were significantly higher and the apoptotic index was significantly lower than they of the control groups,the seventh day blastocyst rate of 50 ng/mL group was significantly higher than that of the control group.Experiment 3: Effect of VEGF on the pre-implantational development and blastocyst quality of porcine parthenogenetic embryos.VEGF at different concentrations(the control group: 0 ng/mL;the treatment groups: 5,25,50 ng/mL)was added into the defined culture medium.The cleavage rate of 5,25,50 ng/mL groups was significantly higher than that of the control group,the blastocyst rate of the sixth day,the seventh day and the max of 5 ng/mL group were significantly higher than they of the control group,the seventh day’s blastocyst rate of 25 ng/mL group was significant higher than that of the control group.Experiment 4: On the basis of experiment 4,effect of 5 ng/mL VEGF on the pre-implantational development and blastocyst quality of porcine parthenogenetic embryos according to the day.When the embryos were cultured with VEGF for the whole culture period,the cleavage rate was significantly higher than that of the control group,the seventh day blastocyst rate was significantly higher when the embryos were cultured with VEGF during the whole culture period and the later stage,the max blastocyst rate was significantly higher when the embryos were cultured with VEGF during the whole culture period.There was no significant difference in the total cell number,the apoptotic cell number or the apoptotic index.In summary,it was the first to reveal the real effect of VEGF on the pre-implantational development of porcine embryos by the chemically defined medium.In the porcine oocytes matured,VEGF(5ng/mL)could significantly increased the maturation rate,VEGF(25ng/mL)could significantly increased the blastocyst rate and reduced the apoptotic index.In the porcine parthenogenetic embryos development,VEGF(5ng/mL)could significantly increased the blastocyst rate and reduced the maturation rate,and VEGF had a significantly effect on the later stage.In conclusion,the study was the first to prove that VEGF had a promoting effect on the oocytes maturation(granule cell layer wrap ≤1)and the parthenogenetic embryos development and had an inhibitory effect on the cell apoptosis.It had laid a solid foundation for the further study of VEGF on the pre-implantational development and the efficiency of porcine embryos.