The Expression, Locatization And Effect Of PTEN In Preimplation Mouse Embryo

The purpose of this study is to investigate the function and effects of PTEN during mouse pre-implantation embryos development.In the Exp1,We investigated expression and localization of PTEN during preimplantation embryosop development. The results of Q-PCR shows that the expression level of PTEN mRNA reduced gradually from oocyte to 2 cell stage,and has another decreasing tendency during morule to blastocyst stage. There is a significant difference between 8-cell stage and the morule to blastocyst stage.But the differences between oocyte and zygote, 2 cells and 8 cells, morule and blastocyst are not significant. The change of PTEN protein is a complex process. It reduced from GV stage, get an increase in zygote, decrease again in 2-cells stage, enhanced in 8-cells stage and morule, and gradually reduced during blastocyst. The localization of PTEN protein is also asymmetric distribution. The protein transferred from nuclear to membranes along with the oocyte. The next time it appears in the nuclear of 8-cells stage. In the morule and blastocyst stage, it only concentrated in trophoblast cells. The PTEN enzymatic activity also show obvious changes in 2cell and blastocyst embryos, which was higher compared with other stages of embryos. The results indicated that there is an interesting change of expression and localization of PTEN in preimplantation embryos. This change may correlative with the biochemical activity, such as cell division, apoptosis, cell differentiation and cell migration in which PTEN involved.In the Exp2,We added bpv(pic),PTEN menzyme activator inhibitor to culture media.And 2cell embryos collected from in vivo.The results shows that compared with control, the embryos cultured with 10μmol/L inhibitors shows a delayed development, the blastosphere cavity was relatively smaller, the further culture shows the hatched rate is much lower, and the embryo apoptotic rate is significantly higher. 1μmol/L bpv (pic) group and control group embryonic show no obvious difference in morphology. There is no significant difference between 1μmol/L bpv (pic) and control in developmental rate, but 10μmol/L group is much lower. The results of TUNEL staining shows that the number of cell apoptosis is significantly higher in both 1μmol/L bpv(pic)and10μmol/L bpv(pic)than control. The results indicated that PTEN is involved in the preimplantation embryos development, and affects the formation of blastocoele.