Proper segregation during meiosis requires that homologs be connected by the combination of crossovers and sister chromatid cohesion. To generate crossovers, numerous double-strand breaks (DSBs) are introduced throughout the genome by the conserved Spo11 endonuclease. DSB formation and its repair are then highly regulated to ensure that homologous chromosomes contain at least one crossover and no DSBs remain prior to meiosis I segregation. The synaptonemal complex (SC) is a meiosis-specific structure formed between homologous chromosomes during prophase that promotes DSB formation and biases repair of DSBs to homologs over sister chromatids. Synapsis occurs when a particular recombination pathway is successful in establishing stable interhomolog connections. In this issue of Genes & Development, Mu and colleagues (pp. 1605–1618) show that SC formation between individual chromosomes provides the feedback to down-regulate Spo11 activity, thereby revealing an additional function for the SC.

中文翻译：

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突触复合物在减数分裂重组调控中的新作用

减数分裂过程中正确的隔离要求同系物通过交叉和姐妹染色单体内聚力的结合来连接。为了产生交叉，通过保守的Spo11核酸内切酶在整个基因组中引入了许多双链断裂（DSB）。然后高度调节DSB的形成及其修复，以确保同源染色体至少包含一个交叉，并且在减数分裂I分离之前没有DSB残留。突触复合物（SC）是前期同源染色体之间形成的减数分裂特异性结构，可促进DSB的形成并使DSB的修复偏向于姐妹染色单体上的同源物。当特定的重组途径成功建立稳定的同源同源连接时，发生突触。在本期《基因与发展》中，Mu及其同事（第1605–1618页）表明，单个染色体之间的SC形成提供了下调Spo11活性的反馈，从而揭示了SC的其他功能。