Chromosome sites play dual roles to establish homologous synapsis during meiosis in C-elegans
Chromosome sites play dual roles to establish homologous synapsis during meiosis in C-elegans
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DOI：
10.1016/j.cell.2005.09.034
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发表时间：
2005-12-16
期刊：
影响因子：
64.5
通讯作者：
Dernburg, AF
中科院分区：
文献类型：
--
作者：
Macqueen, AJ;Phillips, CM;Dernburg, AF
我们研究了配对中心(PC)的作用，这是在线虫减数分裂过程中准确分离同源染色体所需的顺式作用位点。我们发现，这些站点扮演着两个不同的角色，有助于适当的种族隔离。缺乏PC的染色体通常不能突触，也缺乏突触非依赖性的稳定活性。仅在染色体对的一个副本上存在PC可促进突触，但不支持突触独立配对稳定，这表明这些功能是可分离的。一旦启动，突触是高度进行性的，甚至在不同长度的非同源染色体之间也是如此，这阐明了易位如何抑制线虫的减数分裂重组。这些发现提示了染色体突触的多步骤途径，在该途径中，PC通过“动力学校对”机制传递选择性和效率。我们推测，这些活动集中在每个染色体的一个区域可能与失去一个点着丝粒共同进化，以维护核型稳定。
We have investigated the role of pairing centers (PCs), cis-acting sites required for accurate segregation of homologous chromosomes during meiosis in C. elegans. We find that these sites play two distinct roles that contribute to proper segregation. Chromosomes lacking PCs usually fail to synapse and also lack a synapsis-independent stabilization activity. The presence of a PC on just one copy of a chromosome pair promotes synapsis but does not support synapsis independent pairing stabilization, indicating that these functions are separable. Once initiated, synapsis is highly processive, even between nonhomologous chromosomes of disparate lengths, elucidating how translocations suppress meiotic recombination in C. elegans. These findings suggest a multistep pathway for chromosome synapsis in which PCs impart selectivity and efficiency through a "kinetic proofreading" mechanism. We speculate that concentration of these activities at one region per chromosome may have coevolved with the loss of a point centromere to safeguard karyotype stability.