SYCP2 and SYCP3 are required for cohesin core integrity at diplotene but not for centromere cohesion at the first meiotic division
SYCP2 and SYCP3 are required for cohesin core integrity at diplotene but not for centromere cohesion at the first meiotic division
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DOI：
10.1242/jcs.02362
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发表时间：
2005-05-15
影响因子：
4
通讯作者：
Höög, C
中科院分区：
文献类型：
--
作者：
Kouznetsova, A;Novak, I;Höög, C
减数分裂前体蛋白-I染色体轴的大部分组织归因于两组蛋白质：轴向元件蛋白质SYCP 2和SYCP 3;以及粘着蛋白复合物蛋白质。虽然黏结蛋白复合物蛋白确保姐妹染色单体在减数分裂期间保持配对，但SYCP 2和SYCP 3的作用尚不清楚。有趣的是，SYCP 3和SYCP 2与男性而非女性的中期I染色体的着丝粒区域相关，这表明这两种蛋白质具有性别特异性功能。我们分析了空间分布的cohesin复合物蛋白与减数分裂染色体在生殖细胞来自Sycp 3缺陷的女性和男性小鼠。我们发现，在SYCP 3的情况下，与女性减数分裂染色体的凝聚核心过早解体在双线期阶段的减数分裂。我们还表明，SYCP 3和SYCP 2是不需要的着丝粒凝聚在中期-I阶段的男性生殖细胞。我们的结论是，SYCP 3有一个时间限制的作用，在维持，但不是建立，cohesin-core组织在前期I。这一发现支持了一个模型，其中在减数分裂和有丝分裂细胞中，在后期前期从配对的姐妹染色单体中去除大量的粘着蛋白，确保了适当的染色体压实和分离。
Much of the organization of the meiotic prophase-I chromosome axis is attributed to two groups of proteins: the axial element proteins, SYCP2 and SYCP3; and the cohesin-complex proteins. Although the cohesin-complex proteins ensure that sister chromatids remain paired during meiosis, the role of SYCP2 and SYCP3 is not clear. Interestingly, it has been shown that SYCP3 and SYCP2 associate with the centromere regions of male, but not female, metaphase-I chromosomes, suggesting a sex-specific function for the two proteins. We have analysed the spatial distribution of cohesin-complex proteins associated with meiotic chromosomes in germ cells derived from Sycp3-deficient female and male mice. We show that, in the absence of SYCP3, the cohesin cores associated with the female meiotic chromosomes disassemble prematurely at the diplotene stage of meiosis. We also show that SYCP3 and SYCP2 are not required for centromere cohesion at the metaphase-I stage in male germ cells. We conclude that SYCP3 has a temporally restricted role in maintaining, but not establishing, cohesin-core organization during prophase I. This finding supports a model in which the removal of bulk cohesin from paired sister chromatids at late prophase in both meiotic and mitotic cells ensures proper chromosome compaction and segregation.