A Surveillance System Ensures Crossover Formation in C. elegans
A Surveillance System Ensures Crossover Formation in C. elegans
复制标题
DOI：
10.1016/j.cub.2016.09.007
复制
发表时间：
2016-11-07
期刊：
影响因子：
9.2
通讯作者：
Yanowitz, Judith L.
中科院分区：
文献类型：
--
作者：
Machovina, Tyler S.;Mainpal, Rana;Yanowitz, Judith L.
交叉(CO)重组在同系物之间建立了物理连接，从而促进了它们在减数分裂I(MI)时的适当分离。未能实现专有CO会导致同系物独立地附着在MI纺锤体上并随机分离，导致不分离。然而，决定同源基因对是否接受了交叉的机制仍然是个谜。在这里，我们描述了线虫的一个监测系统，该系统监测重组中间体，并将它们的形成与减数分裂进程相结合。需要重组中间体来激活系统，如果即使一个染色体上缺少交叉前体，系统就会延迟进一步的处理。联会复合体是一种连接同源染色体的特殊蛋白质结构，在接受交叉的顺式染色体上稳定，在缺乏交叉的染色体上不稳定，这一过程依赖于Polo样激酶PLK-2的功能。这些结果揭示了交叉承诺的中间体和联会复合体之间的新的通信层，该复合体起到顺式作用、专有的、交叉计数机制的作用。
Crossover (CO) recombination creates a physical connection between homologs that promotes their proper segregation at meiosis I (MI). Failure to realize an obligate CO causes homologs to attach independently to the MI spindle and separate randomly, leading to nondisjunction. However, mechanisms that determine whether homolog pairs have received crossovers remain mysterious. Here we describe a surveillance system in C. elegans that monitors recombination intermediates and couples their formation to meiotic progression. Recombination intermediates are required to activate the system, which then delays further processing if crossover precursors are lacking on even one chromosome. The synaptonemal complex, a specialized, proteinaceous structure connecting homologous chromosomes, is stabilized in cis on chromosomes that receive a crossover and is destabilized on those lacking crossovers, a process that is dependent on the function of the polo-like kinase PLK-2. These results reveal a new layer of communication between crossover committed intermediates and the synaptonemal complex that functions as a cis-acting, obligate, crossover-counting mechanism.