Coculture of in vitro fertilized bovine embryos with oviductal epithelial cells originating from different stages of the estrous cycle.

Bovine embryos derived from in vitro fertilization procedures were cocultured in vitro with oviductal cells obtained from heifers between d 4 and 6 or d 14 and 16 of the estrous cycle. In addition, proteins secreted by oviductal cells isolated between d 4 and 6 or d 14 and 16 of the cycle were monitored. Embryos (2- to 4-cell) were incubated in Tissue Culture Medium-199 with 10% fetal bovine serum with or without oviductal cells at 39 degrees C for 10 d following in vitro insemination. There were more morulae, blastocysts, and hatched blastocysts following coculture with oviductal cells than with culture in medium alone. However, no differences were noted in embryo development following coculture with oviductal cells obtained between d 4 and 6 or d 14 and 16 of the estrous cycle. Also, no differences were detected in the amount of [35S]methionine-labeled proteins secreted by oviductal cells isolated from different days of the estrous cycle. These results indicate that oviductal epithelial cells isolated from early and late luteal phases of the estrous cycle will effectively support early embryonic development following prolonged in vitro culture.