Abstract:

Objective To detect the expression levels of serum and glucocorticoid-induced protein kinase 3 （SGK3） in one-cell stage fertilized eggs at different cell cycles of the mice and its subcellular localization， and to preliminarily clarify the regulatory effect of SGK3 on the early development of fertilized eggs of the mammal. Methods The one-cell stage fertilized eggs of the mice were collected by superovulation technique and in vitro culture of fertilized eggs， the expression levels of SGK3 mRNA and protein in the one-cell stage fertilized eggs at different cell cycles were detected by real-time fluorescence quantitative PCR （RT-qPCR） and Western blotting methods， respectively； the subcellular localization of SGK3 in the one-cell stage fertilized eggs at different cell cycles of the mice was observed by immunofluorescence assay. Results The SGK3 mRNA and protein were expressed in the one-cell stage fertilized eggs at different cell cycles of the mice；compared with G₁， S and M phases， the expression levels of SGK3 mRNA and protein in one-cell phase fertilized eggs at G₂ phase were increased（P<0.01）. The immunofluorescence results showed that SGK3 （red fluorescence） was localized in cytoplasm of the one-cell phase fertilized eggs at G₁ and S phases， and some SGK3 entered into the nucleus at G₂ phase，and the SGK3 was widely distributed throughout the cells at M phase. Conclusion The SGK3 in the one-cell stage fertilized eggs at different cell cycles of the mice dynamically expresses， and SGK3 is shuttered between the nucleus and cytoplasm during the process of fertilized egg cell division， and the altered localization of SGK3 may drive the G₂/M transition and mitotic progression in one-cell stage fertilized eggs of the mice.

Key words: Serum and glucocorticoid induced protein kinase 3, Mitosis, Cell cycle, Fertilized eggs