Molecular architecture, dynamics and evolution of the synaptonemal complex

突触复合体是介导同源染色体突触的减数分裂特异性结构，在染色体重组和分离中起关键作用。无法组装SCs会对配子发生产生严重影响，从而导致不孕。SC的结构和功能在进化上是高度保守的。值得注意的是，根据文献，SC蛋白成分并非如此：酵母、拟南芥、隐杆线虫、果蝇和小鼠等减数分裂模式生物中SC蛋白的比较显示，功能相关蛋白的初级序列存在明显差异。然而，我们提供的初步证据表明，SC的主要结构蛋白（即SYCP1和SYCP3）在后生动物进化过程中会形成单系蛋白群。为了详细研究这一点，我们提出了哺乳动物和基础后生动物（如水螅）之间SC结构、组成和动态的比较分析。直接比较水螅和哺乳动物的结果，将有助于深入了解过去6亿年的后生动物进化过程中减数分裂的基本特征。

Synaptonemal complexes are meiosis-specific structures that mediate synapsis of homologous chro-mosomes and play a key role in recombination and chromosome segregation. The inability to assem-ble SCs has dramatic consequences for gametogenesis that can lead to infertility. The structure and functions of the SC are evolutionarily highly conserved. Remarkably, according to the literature this is not the case for the SC protein components: The comparison of SC proteins in meiosis model organ-isms as yeast, Arabidopsis, Caenorhabditis, Drosophila and mouse reveals clear differences in the primary sequences of functionally related proteins. However, here we provide preliminary evidence that major structural proteins of the SC (i.e. SYCP1 and SYCP3) would form monophyletic groups of proteins across metazoan evolution. In order to investigate this important point in detail, we propose a comparative analysis of SC structure, composition and dynamics between mammals and basal metazoans (i.e. hydra). A direct comparison of the results in hydra and mammals would provide deep insight into the essential features of meiosis over the last 600 million years of metazoan evolution.