人类染色体“牵手”之谜揭开 罗伯逊易位融合点首次精确定位

Core Insights - The research conducted by the Stowers Institute for Medical Research has successfully pinpointed the fusion points of human chromosomes during the formation of Robertsonian translocations, marking a significant milestone in understanding chromosomal behavior and evolution [1][2] - The study reveals that previously considered "junk" DNA, specifically repetitive DNA sequences, may play a crucial role in genomic organization and evolution [1] Group 1: Mechanism of Robertsonian Translocation - Robertsonian translocation occurs when the long arms of two chromosomes fuse, resulting in a total of 45 chromosomes instead of the usual 46, which can lead to infertility issues [2] - The research indicates that the stability of the fused chromosomes is maintained because, despite having two centromeres, only one is active, preventing them from being pulled apart during cell division [2] Group 2: Genetic Implications and Broader Context - The study found that the SST1 repetitive DNA sequence is located at the breakpoints of the Robertsonian translocation chromosomes, suggesting that proximity of these sequences in the nucleolus may trigger fusion [1][2] - Robertsonian translocations are not exclusive to humans; they are also prevalent in various plant and animal species, providing new insights into chromosomal differences across species in nature [2]