TRANSFORMATION-ASSOCIATED RECOMBINATION BETWEEN DIVERGED AND HOMOLOGOUS DNA REPEATS IS INDUCED BY STRAND BREAKS
TRANSFORMATION-ASSOCIATED RECOMBINATION BETWEEN DIVERGED AND HOMOLOGOUS DNA REPEATS IS INDUCED BY STRAND BREAKS
复制标题
DOI：
10.1002/yea.320100109
复制
发表时间：
1994-01-01
期刊：
影响因子：
2.6
通讯作者：
RESNICK, MA
中科院分区：
文献类型：
--
作者：
LARIONOV, V;KOUPRINA, N;RESNICK, MA
在真核细胞的转化过程中经常观察到质粒DNA内的重排。重排的一个可能原因可能是质粒中的某些损伤诱导的重复序列之间的重组。我们已经研究了转化相关的重组在酵母酿酒酵母中使用的质粒系统，允许的物理状态和/或程度的同源性重组的影响进行研究的机制。质粒含有URA 3基因（来自S.酿酒酵母或S. carlsbergensis），通过遗传上可检测的ADE 2颜色标记分离。共价闭合的环状质粒转化过程中的纯化是有丝分裂生长过程中的100倍以上。重组的频率部分取决于转化的方法，因为涉及乙酸锂或造球的程序产生比电穿孔更高的频率。当存在于重复序列中时，可连接的独特单链断裂以及双链断裂导致分叉和相同重复序列之间的高水平重组。重复DNA之间的转化相关重组受RAD 52和RAD 1基因的影响。
Rearrangements within plasmid DNA are commonly observed during transformation of eukaryotic cells. One possible cause of rearrangements may be recombination between repeated sequences induced by some lesions in the plasmid. We have examined the mechanisms of transformation-associated recombination in the yeast Saccharomyces cerevisiae using a plasmid system which allowed the effects of physical state and/or extent of homology on recombination to be studied. The plasmids contain homologous or diverged (19%) repeats of the URA3 genes (from S. cerevisiae or S. carlsbergensis) separated by the genetically detectable ADE2 colour marker. Recombination during transformation for covalently closed circular plasmids was over 100-fold more frequent than during mitotic growth. The frequency of recombination is partly dependent on the method of transformation in that procedures involving lithium acetate or spheroplasting yield higher frequencies than electroporation. When present in the repeats, unique single-strand breaks that are ligatable, as well as double-strand breaks, lead to high levels of recombination between diverged and identical repeats. The transformation-associated recombination between repeat DNAs is under the influence of the RAD52 and RAD1 genes.