Vero cells, but not oviductal cells, increase the hatching frequency and total cell count of mouse blastocysts partly by changing energy substrate concentrations in culture medium.

PURPOSE: To investigate the embryotrophic mechanisms of Vero and oviductal cells coculture.
METHODS: Mouse embryos were cultured in Chatot, Ziomek, and Bavister medium (CZB), in modified CZB media (MM) with nutrient concentrations adjusted to that found in conditioned media after different periods of Vero cells or oviductal cells culture, in reconstituted medium (RM) containing the purified > 100-kDa components of Vero cell conditioned medium that had been reconstituted with CZB medium, and cocultured with Vero cells with an interposing membrane.
RESULTS: The blastulation rate was not different among embryos cultured in different Vero-cell-derived MMs. Nine-hour Vero-cell-derived MM significantly increased the total cell number and hatching frequency of the embryos. There was no difference in these parameters with oviductal-cell-derived MMs. The RM of Vero cells did not possess embryotrophic activity. The presence of a porous membrane between Vero cells and embryos did not affect the embryotrophic activity of coculture.
CONCLUSIONS: Vero cells, but not oviductal cells, improved mouse embryo development partly by modifying the energy substrate concentration in culture medium.