摘要 : DNA double-strand breaks (DSBs) are a common form of DNA damage and DSB rejoining is a fundamental mechanism of genome protection. Breaks arise through direct action of ionizing radiation or some chemicals, and indirectly as a pro... 展开 DNA double-strand breaks (DSBs) are a common form of DNA damage and DSB rejoining is a fundamental mechanism of genome protection. Breaks arise through direct action of ionizing radiation or some chemicals, and indirectly as a product of blocked replication forks. The ability to repair DSBs and to ensure that repair is performed with appropriate fidelity is a fundamental part of genome protection. Repair of DSBs is of cardinal importance to prevent chromosomal fragmentation, translocations and deletions. In the somatic cells the genomic instability resulting from persistent or incorrectly repaired DSBs can lead to carciriogenesis through activation of oncogenes, inactivation of tumour-suppressor genes or loss of hetero-zygosity, while in the germ line they can lead to inborn defects (1,2). 收起