RESUMO
<p><b>OBJECTIVE</b>To investigate the effects of mouse preimplantation embryos on the expressions of DNA methyltransferase 1(Dnmt1) of mouse oviduct epithelial cells.</p><p><b>METHODS</b>The histological location of Dnmt1 protein was detected by immunohistochemical staining and the expression levels of Dnmt1 mRNA and protein in mouse oviduct were assayed by real-time reverse transcription-PCR(RT-PCR) and Western blotting in both pregnant and pseudopregnant mice at the 2-cell, 4-cell and 8-cell stages.</p><p><b>RESULTS</b>The expressions of Dnmt1 protein were mainly located in the epithelial cells of mouse oviduct. It was found that during all three stages, the expression levels of Dnmt1 mRNA in the epithelial cells of the pregnant mice were significantly lower than those in the pseudopregnant mice (P< 0.05), and the level of Dnmt1 protein expression in the pregnant mice was significantly decreased as compared with that in pseudopregnant mice at the 4-cell stage.</p><p><b>CONCLUSION</b>Expressions of both Dnmt1 mRNA and protein in the epithelial cells of mouse oviduct could be regulated by mouse preimplantation embryos, which might play an important role in the expression changes of some genes in oviduct epithelial cells during the preimplantation period.</p>