Meiosis induced by inactivation of Pat1 kinase proceeds with aberrant nuclear positioning of centromeres in the fission yeast Schizosaccharomyces pombe
Meiosis induced by inactivation of Pat1 kinase proceeds with aberrant nuclear positioning of centromeres in the fission yeast Schizosaccharomyces pombe
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DOI：
10.1111/j.1356-9597.2004.00760.x
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发表时间：
2004-08-01
期刊：
影响因子：
2.1
通讯作者：
Hiraoka, Y
中科院分区：
文献类型：
--
作者：
Chikashige, Y;Kurokawa, R;Hiraoka, Y
染色体的核组织在减数分裂期间发生显着变化。在裂殖酵母粟酒裂殖酵母中，着丝粒在有丝分裂细胞周期中聚集在纺锤体（SPB）处；然而，在减数分裂前期，端粒聚集到 SPB，着丝粒从 SPB 分离。我们追踪了活的粟酒裂殖酵母细胞中端粒、着丝粒和姐妹染色单体的运动，这些细胞通过 Pat1 激酶（减数分裂的关键负调节因子）失活而诱导减数分裂。活细胞中的时间过程观察确定了 DNA 合成、端粒聚类、着丝粒分离和减数分裂染色体分离的时间顺序。当有丝分裂 G1 期 Pat1 失活诱导减数分裂时，端粒按照正常减数分裂聚集到 SPB，但在大多数细胞中，着丝粒仍然部分与 SPB 相关。当减数分裂在 G2 期因 Pat1 失活而启动时，端粒和着丝粒在大多数细胞中都保留了它们的有丝分裂核位置。这些结果表明，在某些事件中，Pat1 失活诱导的减数分裂进展与正常减数分裂是异常的。由于 Pat1 失活通常可用于诱导粟酒裂殖酵母细胞同步进入减数分裂，因此此处确定的染色体事件的时间顺序将为 Pat1 失活下游减数分裂的进展提供里程碑。
Nuclear organization of chromosomes proceeds with significant changes during meiosis. In the fission yeast Schizosaccharomyces pombe, centromeres are clustered at the spindle-pole body (SPB) during the mitotic cell cycle; however, during meiotic prophase telomeres become clustered to the SPB and centromeres dissociate from the SPB. We followed the movement of telomeres, centromeres and sister chromatids in living S. pombe cells that were induced to meiosis by inactivation of Pat1 kinase (a key negative regulator of meiosis). Time-course observation in living cells determined the temporal order of DNA synthesis, telomere clustering, centromere separation and meiotic chromosome segregation. When meiosis was induced by Pat1 inactivation at the G1 phase of mitosis, telomeres clustered to the SPB as per normal meiosis, but in most cells the centromeres remained partially associated with the SPB. When meiosis was initiated at the G2 phase by Pat1 inactivation, both telomeres and centromeres retained their mitotic nuclear positions in the majority of cells. These results indicate that the progression of meiosis induced by Pat1 inactivation is aberrant from normal meiosis in some events. As Pat1 inactivation is often useful to induce S. pombe cells synchronously into meiosis, the temporal order of chromosomal events determined here will provide landmarks for the progression of meiosis downstream the Pat1 inactivation.