{"id":379,"title":"Stepwise pairing and fast transition regulated by recombination drive meiotic chromosome interactions","title_zh":"减数分裂同源染色体分步配对及重组驱动的快速转换机制","url":"https://pubmed.ncbi.nlm.nih.gov/42918807","doi":"10.1038/s41467-026-78036-4","pmid":"42918807","journal":"Nat Commun","kind":"paper","lang":"en","published_at":"2026-09-24T00:00:00+00:00","fetched_at":"2026-11-08T03:44:12+00:00","authors":["de Almeida LP","Butler VM","Marin L","Nowak KP","Ostoja-Helczynski M","Ragsdale C","Kawecka MK","Carr KD","Cohen PE","Dresser ME","Burgess SM","Finn EH","Pezza RJ"],"primary_topic":"oocyte","topics":[{"slug":"oocyte","score":5.0,"hits":["meiosis","meiotic"]},{"slug":"art-clinical","score":1.0,"hits":["trigger"]},{"slug":"embryology-lab","score":1.0,"hits":["time-lapse"]},{"slug":"repro-aging","score":1.0,"hits":["telomere"]},{"slug":"ethics-policy","score":1.0,"hits":["regulation"]}],"topic_score":5.0,"preference_score":0.0,"preference_labels":[],"llm_score":80.0,"final_score":88.0,"score_dims":{"novelty":88,"rigor":85,"impact":75,"relevance":72,"translation":45},"recommend_reason":"活体成像清晰揭示同源染色体分步配对及重组事件调控节点，对理解减数分裂染色体不分离和生殖遗传机制有参考价值；但属基础机制研究，对ART实验室的直接转化有限。","keywords":["减数分裂","同源染色体配对","重组","联会复合体","活体成像","小鼠精子发生"],"selected":1,"story_id":430,"llm_provider":"deepseek","llm_model":"deepseek-flash","llm_effort":"low","source_key":"pubmed-top-journals","source_name":"PubMed · CNS/大子刊/四大医学刊（生殖相关）","source_tier":1,"mention_count":1,"has_interpretation":false,"journal_key":"nat-commun","journal_tier":"cns-sub","journal_if":14.7,"is_mock":false,"summary_zh":"研究在小鼠生精小管活体组织中建立基于lac operator-lac repressor的荧光报告系统，结合3D延时成像定量端粒引导的染色体运动和同源染色体配对。发现同源染色体配对呈离散分步过程：平均距离由4.8 µm到1.7 µm再到0.7 µm，紧密配对与联会复合体建立相关；双链断裂和早期重组事件触发从远距离向中间距离的快速转换，紧密配对则依赖交叉成熟中间体及SYCP1/联会复合体。结论揭示高等真核生物减数分裂染色体配对与调控机制。","summary":"Maternal and paternal homologous chromosomes recognize each other and pair during meiosis to ensure accurate chromosome segregation. However, the mechanisms that drive chromosome pairing and their regulation remain poorly understood. To investigate this, we develop a fluorescence reporter-operator system based on the lac operator-lac repressor system, enabling real-time observation of specific genomic loci in live mouse seminiferous tubule tissues. Using 3D time-lapse imaging, we visualize and quantify telomere-led rapid chromosome movements and homologous chromosome pairing. Our results reveal that homologous chromosomes achieve pairing in discrete, well-defined steps. Initially, at the onset of meiosis, chromosomes come together from widely separated positions at an average distance of 4.8 µm, followed by an intermediate stage of pairing at an average distance of 1.7 µm. Finally, close pairing is achieved at an average distance of 0.7 µm, which correlates with the establishment of the synaptonemal complex along the homologs. Further analysis of inter-spot distance dynamics reveals a relatively rapid transition from an initial, widely separated distance to an intermediate stage of chromosome pairing. Complementary studies of recombination mutants using 3D DNA fluorescence in situ hybridization (FISH) on whole-mounted tubules and immunofluorescence on chromosome spreads reveal that double-strand breaks and early recombination events trigger the transition from a widely separated to an intermediate inter-homolog distance. Subsequently, close pairing requires crossover maturation intermediates and SYCP1/synaptonemal complex. Together, our findings reveal a recurring mechanism of meiotic chromosome pairing and how it is regulated by critical meiotic processes in higher eukaryotes.","interpretation_basis":null,"fulltext_status":"error","interpretation":null,"fulltext":{"available":false,"status":"error","reason":"抓取失败：HTTP 500 https://www.ebi.ac.uk/europepmc/webservices/rest/PMC13691100/fullTextXML","pmcid":"PMC13691100","license":null,"chars":0,"source":"Europe PMC","fetched_at":"2026-11-08T04:17:01+00:00"}}