Davis Allison P, Symington Lorraine S
Department of Microbiology and Institute of Cancer Research, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
Mol Cell Biol. 2004 Mar;24(6):2344-51. doi: 10.1128/MCB.24.6.2344-2351.2004.
A chromosome fragmentation assay was used to measure the efficiency and genetic control of break-induced replication (BIR) in Saccharomyces cerevisiae. Formation of a chromosome fragment by de novo telomere generation at one end of the linear vector and recombination-dependent replication of 100 kb of chromosomal sequences at the other end of the vector occurred at high frequency in wild-type strains. RAD51 was required for more than 95% of BIR events involving a single-end invasion and was essential when two BIR events were required for generation of a chromosome fragment. The similar genetic requirements for BIR and gene conversion suggest a common strand invasion intermediate in these two recombinational repair processes. Mutation of RAD50 or RAD59 conferred no significant defect in BIR in either RAD51 or rad51 strains. RAD52 was shown to be essential for BIR at unique chromosomal sequences, although rare recombination events were detected between the subtelomeric Y' repeats.
采用染色体片段化分析方法来测定酿酒酵母中断裂诱导复制（BIR）的效率和遗传控制。在野生型菌株中，线性载体一端通过从头生成端粒形成染色体片段，以及载体另一端100 kb染色体序列的重组依赖性复制，均高频发生。超过95%涉及单端侵入的BIR事件需要RAD51，并且当生成染色体片段需要两个BIR事件时，RAD51是必不可少的。BIR和基因转换相似的遗传需求表明这两个重组修复过程存在共同的链侵入中间体。RAD50或RAD59的突变在RAD51或rad51菌株的BIR中均未造成显著缺陷。尽管在亚端粒Y'重复序列之间检测到罕见的重组事件，但RAD52被证明对于独特染色体序列的BIR是必不可少的。
