Association of p34cdc2 and cyclin B1 during meiotic maturation in porcine oocytes.
Association of p34cdc2 and cyclin B1 during meiotic maturation in porcine oocytes.
复制标题
猪卵母细胞减数分裂成熟过程中 p34cdc2 和细胞周期蛋白 B1 的关联。
作者：
K. Naito;C. Hawkins;M. Yamashita;Y. Nagahama;F. Aoki;K. Kohmoto;Y. Toyoda;R. Moor
p34cdc2 和细胞周期蛋白 B1 的相对水平和关联已在猪卵母细胞从 G2 到中期 II (MII) 的减数分裂过程中测定。完全生长的 G2 停滞猪卵母细胞含有大量游离 p34cdc2 和极少量的 p34cdc2-细胞周期蛋白 B1 复合物，该复合物在 GV 阶段数量没有增加。细胞周期蛋白 B1 直到成熟开始后 23 小时才合成可测量的量。在第一个中期 (MI)，细胞周期蛋白 B1 和 p34cdc2-细胞周期蛋白 B1 复合物的量急剧增加，直到 35 小时。此后，p34cdc2-细胞周期蛋白B1复合物的量再次增加至45小时，导致MII中的复合物水平高于MI中的复合物水平。此外，通过使用抗PSTAIRE抗体进行免疫印迹，在猪卵母细胞中检测到p34cdc2的三种不同迁移形式，并且大多数细胞周期蛋白B1相关的p34cdc2在MI卵母细胞的较低条带中检测到，但在MII期间迁移到第二条带中。这些结果表明，猪卵母细胞中的细胞周期蛋白 B1 水平与海星、蛤和爪蟾卵母细胞中的细胞周期蛋白 B1 水平不同，其中在 GV 阶段似乎存在相当高浓度的细胞周期蛋白 B1，并且 p34cdc2 和细胞周期蛋白 B1 之间的关联性质在第一和第二中期之间发生变化。
The relative levels and association of p34cdc2 and cyclin B1 have been determined in pig oocytes during meiotic progression from G2 to metaphase II (MII). Fully grown G2-arrested porcine oocytes contained large amounts of free p34cdc2 and extremely small amounts of p34cdc2-cyclin B1 complex which did not increase in amount during the GV stage. Cyclin B1 is not synthesized in measurable quantities until 23 hr after the start of maturation. During the first metaphase (MI) the amount of both cyclin B1 and the p34cdc2-cyclin B1 complex increased sharply until 35 hr. Thereafter the amount of the p34cdc2-cyclin B1 complex increased again to 45 hr, resulting in higher levels of the complex in MII than in MI. Moreover, three distinct migration forms of p34cdc2 were detected in pig oocytes by immunoblotting with anti-PSTAIRE antibody, and most of the cyclin B1-associated p34cdc2 was detected in the lower band in MI oocytes but migrated in the second band during MII. These results suggest that cyclin B1 levels in porcine oocytes differ from those in starfish, clam, and Xenopus oocytes in which considerably higher concentrations of cyclin B1 appear to be present during the GV stage and that the nature of the association between p34cdc2 and cyclin B1 changes between the first and the second metaphase.