Zhang Liangyu, Stauffer Weston, Liu Chenshu, Shao Hengyi, Abuzahriyeh Noor, Jiang Rui, Zwicker David, Liu Xing, Yao Xuebiao, Dernburg Abby F
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
Howard Hughes Medical Institute, Chevy Chase, MD, USA.
Nat Cell Biol. 2025 Jun 19. doi: 10.1038/s41556-025-01688-9.
Meiotic recombination mixes genetic information from parental genomes, creating unique combinations of alleles. During meiotic prophase, each homologue pair must undergo at least one crossover to segregate faithfully. Only a few recombination intermediates become crossovers, and these are widely spaced or limited to one per chromosome pair. Mechanisms that regulate crossover number and spacing remain poorly understood. Here we show that, in Caenorhabditis elegans, 'recombination nodules', protein assemblies that stabilize recombination intermediates and promote crossover formation, assemble in part through biomolecular condensation and are stabilized by CDK-2 kinase activity. We further demonstrate that essential components of these nodules move along the synaptonemal complex (SC) and do not freely exchange between SCs in the same nucleus. Our findings reveal that recombination nodules behave as active droplets and support a model in which coarsening of these droplets via protein translocation along liquid crystalline SCs underlies crossover patterning.
减数分裂重组混合了来自亲代基因组的遗传信息，产生了独特的等位基因组合。在减数分裂前期，每对同源染色体必须至少发生一次交叉才能准确分离。只有少数重组中间体成为交叉点，并且它们分布广泛或每个染色体对仅限于一个。调节交叉数量和间隔的机制仍知之甚少。在这里，我们表明，在秀丽隐杆线虫中，“重组结节”，即稳定重组中间体并促进交叉形成的蛋白质组装体，部分通过生物分子凝聚组装，并由CDK-2激酶活性稳定。我们进一步证明，这些结节的基本成分沿着联会复合体（SC）移动，并且不会在同一细胞核内的SC之间自由交换。我们的研究结果表明，重组结节表现为活性液滴，并支持一种模型，即通过沿着液晶SC的蛋白质易位使这些液滴粗化是交叉模式形成的基础。
