The role of MAP kinase cascade in activation of porcine oocytes

MAP激酶的作用在Porcine ocytes的成熟和激活机制是探索的。细胞中的MAP激酶在Metaphase I中被戏剧性地激活，而激活的MAP激酶被激活为强积金。这些结果建议，即MAP激酶的激活是对正常进程的基本要求，进入第二次meiosis的metaphase。进一步，MAP激酶在细胞中激活的证据完全依赖于周围累积累积细胞中PI 3激酶的活动，并诱导了累积细胞和累积细胞之间间隙联合体的关闭，已经提供。下一个区域反应是被评估的Ca-D12 + E-D1瞬态激活的指标。该程序是为了检测单个细胞中的Zona pellucida中的糖蛋白修饰，并已被开发出来。使用这个程序，它演示了在低浓度下由Cai-D12 + i-D1电离膜激活的强积金活动，但MAP ki的活动 ... More 很好，在强积金的反应和强积金进程进入MIII阶段的结果，认为这是一个不正常的事件。Moreover，在低浓度和特定MEK抑制剂中与Cay-D12 + y-D1离子核的联合治疗，U 0126，结果在强积金和MAP激酶活性中的戏剧性滴液，以及两种子激酶活性在基本水平上保持，直到一个丙酮的发展在细胞中被诱导。这些发现清楚地表明，以保持强积金减少的活动对MAP激酶活动的降解是关键的，因为它是对细胞凋亡中的元性成熟和前列核的形成的补充。结合在一起，下面的合成物可以从这个研究中脱落; 1）MAP激酶的活动是由环绕累积细胞调节的。2）MAP激酶的激活是一个超代谢酶I进入代谢酶II的进步的前体。3） MAP kinase is inactivated by elevation of CaイイD12+イエD1 in MII arrested oocytes， which is closely associated with completion of meiosis and formation of pronuclei。Less（低）

The role of MAP kinase during maturation of porcine oocytes and the activation mechanisms were explored. MAP kinase in the oocytes was dramatically activated in metaphase I and the activated MAP kinase led to activation of MPF. These results suggest that the activation of MAP kinase is essential for the normal progression into the metaphase of the second meiosis. Further, the evidences that MAP kinase activation in oocytes were completely dependent on the activity of PI 3-kinase in the surrounding cumulus cells, inducing a shutdown of the gap junctions between oocytes and cumulus cells, were provided. Next, zona reaction which is an indicator of CaィイD12+ィエD1 transients at oocyte activation was assessed. The procedure for detecting a modification of glycoproteins in zona pellucida of a single oocyte, was devised. Using this procedure, it was demonstrated that the MPF activity declined quickly in oocytes activated by CaィイD12+ィエD1 ionophore at low concentration, but the activity of MAP ki … More nase remained high, resulting in reactivation of MPF and the oocyte progression into the MIII stage, which is considered to be the abnormal event. Moreover, the combined treatment with CaィイD12+ィエD1 ionophore at low concentration and specific MEK inhibitor, U0126, resulted in dramatic drop in activities of MPF and MAP kinase, and subsequently activities of both kinase was maintained at the basal level until the development of a pronucleus was induced in the oocytes. These findings clearly demonstrate that maintaining the reduced activity of MPF due to the decline of MAP kinase activity is critical for completion of meiotic maturation and the formation of pronuclei in porcine oocytes. Taken together, the following conclusions can be drown from this study ; 1) The activity of MAP kinase is porcine oocytes is regulated by the surrounding cumulus cells. 2) The activation of MAP kinase is a prerequisite for the progression beyond metaphase I into metaphase II. 3) MAP kinase is inactivated by elevation of CaィイD12+ィエD1 in MII arrested oocytes, which is closely associated with completion of meiosis and formation of pronuclei. Less