A REC8-dependent plant shugoshin is required for maintenance of centrorneric cohesion during meiosis and has no mitotic functions
A REC8-dependent plant shugoshin is required for maintenance of centrorneric cohesion during meiosis and has no mitotic functions
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DOI：
10.1016/j.cub.2005.04.049
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发表时间：
2005-05-24
期刊：
影响因子：
9.2
通讯作者：
Cande, WZ
中科院分区：
文献类型：
--
作者：
Hamant, O;Golubovskaya, I;Cande, WZ
在减数分裂过程中，姐妹染色单体凝聚力(SSC)在连续两次核分裂期间的顺序释放允许二倍体前体细胞产生单倍体配子。SSC沿着染色体臂的释放首先允许同系物的减少分离，随后在后期11的着丝粒凝聚力的释放允许染色单体的分离[1-3]。Shugoshin(SGO)蛋白家族在保护果蝇和酵母的着丝粒凝聚力方面发挥着重要作用[4-12]。我们已经分离到一个玉米突变体，该突变体在后期1表现为着丝粒凝聚力过早丧失。我们证明这种表型是由于缺乏玉米Shugoshin同源物ZmSGO1蛋白所致。我们还证明了ZmSGO1定位于着丝粒。ZmSGO1蛋白不存在于有丝分裂染色体上，没有明显的有丝分裂功能。在这些结果的基础上，我们认为ZmSGO1在减数分裂I过程中特异性地维持着丝粒凝聚力，因此表明SGO1在减数分裂过程中的核心功能在跨王国和大基因组物种中是保守的。然而，与其他Shugoshin不同的是，我们观察到ZmSGO1在玉米中的早期和依赖于Rec8的招募，这表明在植物中对SGO1招募到染色体的控制不同于其他模式生物。
During meiosis, sequential release of sister chromatid cohesion (SSC) during two successive nuclear divisions allows the production of haploid gametes from diploid progenitor cells. Release of SSC along chromosome arms allows first a reductional segregation of homologs, and, subsequently, release of centromeric cohesion at anaphase 11 allows the segregation of chromatids [1-3]. The Shugoshin (SGO) protein family plays a major role in the protection of centromeric cohesion in Drosophila and yeast [4-12]. We have isolated a maize mutant that displays premature loss of centromeric cohesion at anaphase 1. We showed that this phenotype is due to the absence of ZmSGO1 protein, a maize shugoshin homolog. We also show that ZmSGO1 is localized to the centromeres. The ZmSGO1 protein is not found on mitotic chromosomes and has no obvious mitotic function. On the basis of these results, we propose that ZmSGO1 specifically maintains centromeric cohesion during meiosis I and therefore suggest that SGO1 core functions during meiosis are conserved across kingdoms and in large-genome species. However, in contrast to other Shugoshins, we observed an early and REC8-dependent recruitment of ZmSGO1 in maize, suggesting that control of SGO1 recruitment to chromosomes is different in plants than in other model organisms.