On the experimental distinction between ssbs and dsbs in circular DNA
On the experimental distinction between ssbs and dsbs in circular DNA
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DOI：
10.1080/095530098142013
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发表时间：
1998-05-01
影响因子：
2.6
通讯作者：
Hieda, K
中科院分区：
文献类型：
--
作者：
Hanai, R;Yazu, M;Hieda, K
目的：直接测定环状DNA互补链上两个单链断裂之间的最小距离。材料和方法：用一种新的方法系统地制备具有不同长度的结合悬垂的3.2kbpDNA，并在琼脂糖凝胶中进行凝胶电泳。结果：在4℃时，结合悬垂大于6bp的3.2kbpDNA以环状DNA的形式迁移。在25℃时，DNA以环状DNA形式迁移的最小悬垂尺寸较大。DNA作为环状或线形分子迁移也取决于其悬垂的核苷酸序列，最显著的是在最小尺寸。结论：本研究得到的最小距离与先前间接估计的较小值一致。距离与实验条件的依赖关系表明，获得辐射诱导的DSB的交错尺寸分布是可行的。
Purpose: To determine directly the minimal distance between two ssbs on complementary strands in circular DNA that are not observed as a dsb by electrophoresis.Materials and methods: 3.2kbp DNAs with cohesive overhangs of various lengths were systematically generated by a newly devised method and electrophoresed in agarose slabs.Results: At 4 degrees C, 3.2kbp DNA with cohesive overhangs larger than 6 bp migrated as circular DNA. The minimal overhang size for the DNA to migrate as circular DNA was larger at 25 degrees C. Whether the DNA migrated as a circular or a linear molecule depended also on the nucleotide sequence of its overhangs, most notably at the minimal size.Conclusions: The minimal distance obtained in the present study agrees with the smaller values of previous indirect estimates. The dependence of the distance on experimental conditions suggests feasibility of obtaining the stagger-size distribution of radiation-induced dsbs.