Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, 565-0871, Japan.
Curr Genet. 2020 Oct;66(5):881-887. doi: 10.1007/s00294-020-01077-9. Epub 2020 Apr 13.
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 Schizosaccharomyces pombe 中，已经对减数分裂中同源染色体配对的分子机制进行了广泛研究。在该生物中，由特定基因转录的减数特异性非编码 RNA 积累在各自的基因座上，并且与染色体相关的 RNA-蛋白质复合物通过相分离介导同源位点的减数配对。在某些情况下，同源染色体的配对也会发生在体细胞二倍体细胞中。例如，在双翅目动物的早期胚胎发生过程中，同源染色体的体细胞配对依赖于转录相关的染色质结构。早期模型还表明，沿着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，染色体上形成的 RNA 体介导同源染色体的配对。本综述总结了来自 S. pombe 的经验教训，为通过与染色体相关的 RNA-蛋白质复合物的相分离介导的同源染色体配对机制提供了一般性的见解。
