PURPOSE: Our purpose was to evaluate the beneficial effects of long-term coculture of Vero cells on the development of frozen-thawed two-cell mouse embryos. METHODS: Two-cell mouse embryos were frozen slowly with 1,2-propandiol and sucrose as cryoprotectants and thawed rapidly, followed by stepwise dilution. Vero cells were cultured in drops of RPMI 1640 to establish monolayers. Frozen-thawed embryos were cultured alone (control) or cocultured with Vero cells. The rate of development in both groups was compared. RESULTS: After 4 days of culture, significantly more embryos in coculture were developed to expanded blastocysts (61 vs 37% for controls; P < or = 0.0001). In addition, on the fifth day of cultivation, more embryos in coculture showed the potential of hatching from the zona pellucida (26 vs 7% in controls; P < or = 0.0001). The rate of degeneration in coculture was also much lower than in controls (6 and 15%, respectively). CONCLUSIONS: Coculture of cryopreserved preimplantation-stage embryos with Vero cells seems to be a useful tool to eliminate the postthaw deleterious effect of freezing and also to obtain better-quality embryos appropriate for transfer.
PURPOSE: Our purpose was to evaluate the beneficial effects of long-term coculture of Vero cells on the development of frozen-thawed two-cell mouse embryos. METHODS: Two-cell mouse embryos were frozen slowly with 1,2-propandiol and sucrose as cryoprotectants and thawed rapidly, followed by stepwise dilution. Vero cells were cultured in drops of RPMI 1640 to establish monolayers. Frozen-thawed embryos were cultured alone (control) or cocultured with Vero cells. The rate of development in both groups was compared. RESULTS: After 4 days of culture, significantly more embryos in coculture were developed to expanded blastocysts (61 vs 37% for controls; P < or = 0.0001). In addition, on the fifth day of cultivation, more embryos in coculture showed the potential of hatching from the zona pellucida (26 vs 7% in controls; P < or = 0.0001). The rate of degeneration in coculture was also much lower than in controls (6 and 15%, respectively). CONCLUSIONS: Coculture of cryopreserved preimplantation-stage embryos with Vero cells seems to be a useful tool to eliminate the postthaw deleterious effect of freezing and also to obtain better-quality embryos appropriate for transfer.
Authors: J Testart; B Lassalle; J Belaisch-Allart; A Hazout; R Forman; J D Rainhorn; R Frydman Journal: Fertil Steril Date: 1986-08 Impact factor: 7.329