[Cdc25B overexpression reverses two-cell block in mouse embryos]

Abstract

Aim: To explore the effect of Cdc25B overexpression on the development of mouse two-cell embryos.

Methods: The pBSK-Cdc25B was in vitro transcribed into 5'-capped mRNA for microinjection by using mMESSAGE mMACHINE kit. The Cdc25B mRNA was microinjected into mouse embryos at two-cell stage in order to observe the embryonic development and cleavage rate. Using protein kinase activity assay and Western blot to detect the MPF activity as well as the phosphorylation status of Cdc2-Tyr15 in Cdc25B overexpression group respectively.

Results: The mouse embryos with Cdc25B overexpression developed to the four-cell stage 48 h after the hCG injection with the percentage of cleavage over 40% compared with the embryos in control groups which still remained at the two-cell stage. Moreover, MPF activity increased significantly after Cdc25B mRNA injection. The phosphorylation status of Cdc2-Tyr15 was coincident with MPF activity.

Conclusion: The results indicate that Cdc25B overexpression in early mouse two-cell embryos reverses two-cell block and promotes their development into four-cell stage by activating MPF.