FROZEN-THAWED CUMULUS-GRANULOSA CELLS SUPPORT BOVINE EMBRYO DEVELOPMENT DURING COCULTURE

Objective: To evaluate the ability of bovine cumulus-granulosa cells t o survive cryopreservation and subsequently support bovine embryo deve lopment during coculture. Design: In vitro-matured and -fertilized bov ine embryos (two- to four-cell) were allotted randomly to one of three treatment groups: [1] control medium alone consisting of Medium 199 c ontaining 10% fetal bovine serum and antibiotics, [2] cocultured on fr esh bovine cumulus-granulosa cells in control medium, or [3] coculture d on frozen-thawed cumulus-granulosa cells in control medium. Embryo d evelopment was assessed on days 7 and 8 after IVF. Results: Coculture improved embryo development on days 7 and 8 compared with the control group. However, embryo development on days 7 and 8 did not differ amon g coculture groups. Conclusions: Frozen-thawed cumulus-granulosa cells enhance embryo development similar to fresh cells during in vitro coc ulture.