Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia.
Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia.
Genes (Basel). 2020 Apr 2;11(4):386. doi: 10.3390/genes11040386.
Robertsonian translocations are common chromosomal alterations. Chromosome variability affects human health and natural evolution. Despite the significance of such mutations, no mechanisms explaining the emergence of such translocations have yet been demonstrated. Several models have explored possible changes in interphase nuclei. Evidence for non-homologous chromosomes end joining in meiosis is scarce, and is often limited to uncovering mechanisms in damaged cells only. This study presents a primarily qualitative analysis of contacts of non-homologous chromosomes by short arms, during meiotic prophase I in the mole vole, a species with a variable karyotype, due to Robertsonian translocations. Immunocytochemical staining of spermatocytes demonstrated the presence of four contact types for non-homologous chromosomes in meiotic prophase I: (1) proximity, (2) touching, (3) anchoring/tethering, and (4) fusion. Our results suggest distinct mechanisms for chromosomal interactions in meiosis. Thus, we propose to change the translocation mechanism model from 'contact first' to 'contact first in meiosis'.
罗伯逊易位是常见的染色体异常。染色体的多样性会影响人类健康和自然进化。尽管这些突变意义重大，但目前还没有证明其发生的机制。有几个模型探讨了在间期核中可能发生的变化。减数分裂中非同源染色体末端连接的证据很少，而且通常仅限于仅揭示受损细胞中的机制。本研究主要通过免疫细胞化学染色技术，对具有可变染色体组型的鼩鼱（一种由于罗伯逊易位而具有可变染色体组型的物种）的减数分裂前期 I 中，非同源染色体短臂之间的接触进行了定性分析。在减数分裂前期 I 中，免疫细胞化学染色显示，非同源染色体之间存在四种接触类型：（1）接近，（2）接触，（3）锚定/系留，和（4）融合。我们的结果表明减数分裂中染色体相互作用存在不同的机制。因此，我们建议将易位机制模型从“先接触”改为“减数分裂中先接触”。
