Abstract: [Objective] To assess the mRNA and protein expression of pik3r3, Akt and mapk3 genes in sheep oviduct epithelial cells after stimulation with estradiol. [Method] The mRNA and protein expression levels of pik3r3, Akt and mapk3 genes in oviduct epithelial cells within five passages were detected by qPCR and Western blot respectively after incubation with 10-8 mol/L estradiol （equivalent amount of medium instead of estradiol were used as the control group） for 0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 h. [Result] After adding 10-8 mol/L estradiol to sheep oviduct epithelial cells, the mRNA and protein expression levels of pik3r3, Akt and mapk3 genes increased first and then reduced as the incubation time progressed. The mRNA expression （P<0.01） and protein expression （P<0.05） of the pik3r3 gene peaked after 1.5 h treatment with estradiol, whereas the mRNA expression （P<0.01） and protein expression （P<0.05） of the Akt and mapk3 genes peaked at 2.5 h treatment with estradiol. The mRNA expression of pik3r3, Akt and mapk3 genes all significantly （P<0.05） increased after 3.0 h of estradiol treatment. [Conclusion] Estradiol regulates the expression of pik3r3, Akt and mapk3 genes in sheep oviduct epithelial cells. High levels of estrogen facilitate the expression of pik3r3, Akt and mapk3 genes, which is linked to the innate immune defence in the reproductive tract, and may improve the autoimmune response via this mechanism.

Key words: estradiol, oviduct epithelial cells, pik3r3 gene, Akt gene, mapk3 gene