Sato Aya, Isaac Berith, Phillips Carolyn M, Rillo Regina, Carlton Peter M, Wynne David J, Kasad Roshni A, Dernburg Abby F
Howard Hughes Medical Institute, Chevy Chase, MD 20815 USA.
Cell. 2009 Nov 25;139(5):907-19. doi: 10.1016/j.cell.2009.10.039. Epub 2009 Nov 12.
During meiosis, each chromosome must pair with its unique homologous partner, a process that usually culminates with the formation of the synaptonemal complex (SC). In the nematode Caenorhabditis elegans, special regions on each chromosome known as pairing centers are essential for both homologous pairing and synapsis. We report that during early meiosis, pairing centers establish transient connections to the cytoplasmic microtubule network. These connections through the intact nuclear envelope require the SUN/KASH domain protein pair SUN-1 and ZYG-12. Disruption of microtubules inhibits chromosome pairing, indicating that these connections promote interhomolog interactions. Dynein activity is essential to license formation of the SC once pairing has been accomplished, most likely by overcoming a barrier imposed by the chromosome-nuclear envelope connection. Our findings thus provide insight into how homolog pairing is accomplished in meiosis and into the mechanisms regulating synapsis so that it occurs selectively between homologs. For a video summary of this article, see the PaperFlick file with the Supplemental Data available online.
在减数分裂过程中，每条染色体都必须与它独特的同源染色体配对，这一过程通常以联会复合体（SC）的形成为高潮。在秀丽隐杆线虫中，每条染色体上被称为配对中心的特殊区域对于同源配对和联会都至关重要。我们报告称，在减数分裂早期，配对中心与细胞质微管网络建立了瞬时连接。这些通过完整核膜的连接需要SUN/KASH结构域蛋白对SUN-1和ZYG-12。微管的破坏会抑制染色体配对，这表明这些连接促进了同源染色体间的相互作用。一旦配对完成，动力蛋白活性对于许可SC的形成至关重要，最有可能是通过克服染色体-核膜连接所施加的障碍。因此，我们的发现为减数分裂中同源染色体配对是如何完成的以及调节联会的机制提供了见解，从而使其在同源染色体之间选择性地发生。有关本文的视频总结，请参阅在线提供的补充数据中的PaperFlick文件。
