Cell-cycle-dependent subcellular localization of cyclin B1, phosphorylated cyclin B1 and p34cdc2 during oocyte meiotic maturation and fertilization in mouse
Cell-cycle-dependent subcellular localization of cyclin B1, phosphorylated cyclin B1 and p34cdc2 during oocyte meiotic maturation and fertilization in mouse
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DOI：
10.1017/s0967199405003060
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发表时间：
2005-02-01
期刊：
影响因子：
1.7
通讯作者：
Sun, QY
中科院分区：
文献类型：
--
作者：
Huo, LJ;Yu, LZ;Sun, QY
M期或成熟促进因子(MPF)是一种由调节周期蛋白B和催化p34(Cdc2)激酶组成的激酶复合体，在减数分裂和有丝分裂中发挥重要作用。本研究旨在检测和比较细胞周期蛋白131、磷酸化细胞周期蛋白131和p34cdc2在小鼠卵母细胞减数分裂成熟和受精过程中的亚细胞定位。我们发现所有这些蛋白都集中在卵母细胞的生发泡中。生发泡破裂后不久，所有这些蛋白质都聚集在浓缩的染色体周围。随着中期1纺锤体的形成，Cyclin B1和磷酸化Cyclin B1定位于密集染色体周围并集中在纺锤体极部，而p34(Cdc2)定位于纺锤体区域。在后期/末期过渡阶段，磷酸化的细胞周期蛋白B1在分离的染色体/染色单体之间的中体积累，而p34(Cdc2)则在除中体区域外的整个纺锤体中积累。中期II，Cyclin B1和p34(Cdc2)水平定位于染色体对齐区域和纺锤体两极，而磷酸化Cyclin B1定位于纺锤体两极和染色体。在最初形成原核时，受精卵中没有检测到特定的细胞周期蛋白B1的分布，但在晚期的原核中，细胞周期蛋白B1在原核中积累。P34(Cdc2)和磷酸化细胞周期蛋白B1在孤雌激活后集中在一个原核内，受精后集中在两个原核内。在1-细胞胚胎中期，Cyclin B1聚集在密集的染色体周围。Cyclin B1在晚期2-细胞胚胎的细胞核中有积累，而在早期2-细胞胚胎中没有。此外，我们还检测到p34(Cdc2)在2-细胞和4-细胞胚胎的细胞核中积累。这些结果表明，在卵母细胞减数分裂成熟和受精过程中，Cyclin B1、磷酸化Cyclin B1和p34(Cdc2)在某些阶段有相似的分布，但在其他阶段有不同的定位，提示它们可能在卵母细胞成熟和受精过程中的某些事件中发挥共同作用，而在其他事件中发挥不同的作用。
M phase or maturation promoting factor (MPF), a kinase complex composed of the regulatory cyclin B and the catalytic p34(cdc2) kinase, plays important roles in meiosis and mitosis. This study was designed to detect and compare the subcellular localization of cyclin 131, phosphorylated cyclin 131 and p34cdc2 during oocyte meiotic maturation and fertilization in mouse. We found that all these proteins were concentrated in the germinal vesicle of oocytes. Shortly after germinal vesicle breakdown, all these proteins were accumulated around the condensed chromosomes. With spindle formation at metaphase 1, cyclin B1 and phosphorylated cyclin B1 were localized around the condensed chromosomes and concentrated at the spindle poles, while p34(cdc2) was localized in the spindle region. At the anaphase/telophase transition, phosphorylated cyclin B1 was accumulated in the midbody between the separating chromosomes/chromatids, while p34(cdc2) was accumulated in the entire spindle except for the midbody region. At metaphase II, both cyclin B1 and p34(cdc2) were horizontally localized in the region with the aligned chromosomes and the two poles of the spindle, while phosphorylated cyclin B1 was localized in the two poles of spindle and the chromosomes. We could not detect a particular distribution of cyclin B1 in fertilized eggs when the pronuclei were initially formed, but in late pronuclei cychn B1 was accumulated in the pronuclei. p34(cdc2) and phosphorylated cyclin B1 were always concentrated in one pronuclens after parthenogenetic activation or in two pronuclei after fertilization. At metaphase of 1-cell embryos, cyclin B1 was accumulated around the condensed chromosomes. Cyclin B1 was accumulated in the nucleus of late 2-cell embryos but not in early 2-cell embryos. Furthermore, we also detected the accumulation of p34(cdc2) in the nucleus of 2- and 4-cell embryos. All these results show that cyclin B1, phosphorylated cyclin B1 and p34(cdc2) have similar distributions at some stages but different localizations at other stages during oocyte meiotic maturation and fertilization, suggesting that they may play a common role in some events but different roles in other events during oocyte maturation and fertilization.