EFFECT OF ESTROGEN-TREATED PORCINE AMPULLA OVIDUCTAL EPITHELIAL-CELLSON EARLY EMBRYONIC-DEVELOPMENT IN-VITRO AND CHARACTERIZATION OF THEIRPROTEIN SYNTHETIC ACTIVITY

Recent studies by Buhi et al. have demonstrated that estrogen (E(2)) i s responsible for the induction of de novo synthesis and secretion of certain oviductal secretory proteins (OSP) and inhibition of other OSP in porcine oviductal explant cultures. The present work was undertake n to evaluate the effect of E(2)-treated oviductal epithelial cell coc ulture on the development of early porcine embryos derived from in vit ro matured and fertilized oocytes. In vitro synthesis of secretory pro teins by E(2)-treated oviductal cells used for coculture was also inve stigated by one-dimensional (1D) and two-dimensional (2D) sodium dodec yl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE). The result s showed that the cleavage rate was significantly enhanced by cocultur ing fertilized eggs with E(2)-treated oviductal epithelial cells. The in vitro protein synthetic pattern of oviductal secretory proteins was influenced by E(2) treatment. These variations included the disappear ance of one protein (82 000 M(r)) and the appearance of another (33 00 0 M(r)) in the E(2)-treated group as assessed by 1D-SDS-PAGE. Addition al proteins of M(r) 97 000 and an M(r) 36 000-45 000 complex were incr eased in abundance by the E(2) treatment. Analyses by 2D-SDS-PAGE reve aled three major E(2)-dependent proteins, of M(r) 45 000 (pI 5.5), 43 000 (pI 5.5) and a 36 000-45 000 M(r) (pI 4.8) protein complex, wherea s polypeptides of M(r) 97 000 (pI 5.1), 36 000 (pI 8.0) and 25 000 (pI 6.8) were inhibited by E(2) treatment. The results demonstrated that porcine epithelial cell protein synthetic patterns are influenced by E (2) treatment and that estradiol treatment of oviductal cells may incr ease the rate of zygote cleavage during early development in vitro in pigs.