To investigated the mechanism, induced pluripotent stem cells(iPSC) is important for clinical application and stem cell research. It is well known that hMAGEA2 expression pattern and effect on differentiation in embryonic stem cell but their specific role in iPS cells are unclear. The present study was schemed to understand the function of hMAGEA2 gene in iPS cells and to elucidate its characteristic. Although overexpression of hMAGEA2 in iPS cells are not different on morphology, their pluripotency and self-renewal capacity are significantly strengthened. And hMAGEA2 contributed to promote the cell cycle progression, this cell cycle changes induced proliferation acceleration. Through embryoid body formation in vitro and teratoma formation in vivo, we found that hMAGEA2 critically decreases the differentiation ability in iPS cells. Our results demonstrate that hMAGEA2 intensified the self-renewal, pluripotency, proliferation degree but efficiency of differentiaton is significantly repressed. Our findings provided that hMAGEA2 play a key role of iPS cells.

This study was conducted to investigate the effect of vitrification solution(VS) on in vitro developmental competence of immature porcine oocytes. The immature porcine oocytes were exposed to the following vitrification solution, at RT. 1) EFS sol. : 20% ethylene glycol (EG) 3 min, 40% EG + 18%(w/v) Ficoll(MV70, 000) + 0.3 M sucrose 30 sec, 2) GE sol. : 10% glycerol 5 min, 10% G + 20% EG 5 min, 25% G +25% EG 30 sec, 3) EG sol : 1.5M EG 2.5 min, 5.5 M EG + 1.0 M sucrose 30 sec. Oocytes were immediately transferred into 1.0 M, 0.5 M, 0.25 M, 0125 M, 0 M sucrose solution for 2.5 min each at RT. After removal of VS, immature oocytes were matured in vitro and subsequently all oocytes were subjected to IVF followed in vitro culture for 7 days. Maturation rates of oocytes were 38.8%, 44.5%, 22.4% and 57.6%, in EFS, EG, GE and Control, respectively, maturation rates of oocytes in EG and Control was significantly higher than EFS and GE(P<0.01). Fertilization rates of oocytes in Control was significantly higher than other treated groups(P<0.05), but no difference were observed among treated groups. Polyspermic rates were no significant difference among four groups. Cleavage rates of oocytes were 21.9%, 47.1%, 19.0% and 65.9%, in EFS, EG, GE and Control, respectively, cleavage rates of oocytes in EG and Control was significantly higher than EFS and GE(P<0.05), but blastocyst formation rates were no significant difference among four groups. These results suggested that the use of EG solution could be a great challenge for reaching a successful vitrification of immature porcine oocytes.