Pairing of homologous chromosomes is crucial for ensuring accurate segregation of chromosomes during meiosis. Molecular mechanisms of homologous chromosome pairing in meiosis have been extensively studied in the fission yeast Schizosaccharomyces pombe. In this organism, meiosis-specific noncoding RNA transcribed from specific genes accumulates at the respective gene loci, and chromosome-associated RNA–protein complexes mediate meiotic pairing of homologous loci through phase separation. Pairing of homologous chromosomes also occurs in somatic diploid cells in certain situations. For example, somatic pairing of homologous chromosomes occurs during the early embryogenesis in diptera, and relies on the transcription-associated chromatin architecture. Earlier models also suggest that transcription factories along the chromosome mediate pairing of homologous chromosomes in plants. These studies suggest that RNA bodies formed on chromosomes mediate the pairing of homologous chromosomes. This review summarizes lessons from S. pombe to provide general insights into mechanisms of homologous chromosome pairing mediated by phase separation of chromosome-associated RNA–protein complexes.

同源染色体的配对对于确保减数分裂过程中染色体的准确分离至关重要。在裂殖酵母粟酒裂殖酵母中广泛研究了减数分裂中同源染色体配对的分子机制。在这种生物中，从特定基因转录的减数分裂特异性非编码RNA积累在各自的基因位点，与染色体相关的RNA-蛋白质复合物通过相分离介导同源基因座的减数分裂配对。在某些情况下，体染色体二倍体细胞中也会发生同源染色体配对。例如，同源染色体的体细胞配对发生在双足动物的早期胚胎发生期间，并且依赖于转录相关的染色质结构。早期的模型还表明，沿染色体的转录工厂介导植物中同源染色体的配对。这些研究表明，在染色体上形成的RNA体介导了同源染色体的配对。这篇评论总结了S. pombe的经验教训 提供有关染色体相关RNA-蛋白质复合物的相分离介导的同源染色体配对机制的一般见解。