POSITIVE SELECTION OF MUTANTS WITH DELETIONS OF GAL-CHL REGION OF SALMONELLA CHROMOSOME AS A SCREENING-PROCEDURE FOR MUTAGENS THAT CAUSE DELETIONS
POSITIVE SELECTION OF MUTANTS WITH DELETIONS OF GAL-CHL REGION OF SALMONELLA CHROMOSOME AS A SCREENING-PROCEDURE FOR MUTAGENS THAT CAUSE DELETIONS
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DOI：
10.1128/jb.121.1.259-266.1975
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发表时间：
1975-01-01
影响因子：
3.2
通讯作者：
AMES, BN
中科院分区：
文献类型：
--
作者：
ALPER, MD;AMES, BN
我们通过鼠伤寒沙门菌和大肠杆菌的染色体gal区开发了一种方便、特异的长缺失阳性选择方法。通过同时选择两个紧密相连的基因gal和chlA的突变，可以很容易地获得各种不同长度的缺失，有些缺失可以延伸到染色体的1分钟。许多这样的缺失导致了一个基因的缺失，我们将其命名为dhb，该基因与细菌合成铁螯合剂肠杆菌蛋白的能力有关。该选择适用于诱变剂的筛选，因为它们能够在细菌脱氧核糖核酸中产生长缺失。筛选了40名特工以获得这种能力。在我们的系统中，先前报道的亚硝酸盐是一种有效的诱变剂，使缺失突变的频率增加了50倍。另外三种，氮芥、丝裂霉素C和快中子，被证明能使长缺失的频率增加5到8倍。其余的被发现不能产生这些缺失。
We have developed a convenient and specific positive selection for long deletions through the gal region of the chromosomes of Salmonella typhimurium and Escherichia coli. Through simultaneous selection for mutations in the two closely linked genes, gal and chlA, a variety of deletions of varying length, some extending through as much as 1 min of the chromosome, could be readily obtained. Many of these deletions resulted in the loss of a gene, which we named dhb, concerned with the ability of the bacterium to synthesize the iron chelating agent enterobactin. The selection was adapted for the screening of mutagens for their ability to generate long deletions in the bacterial deoxyribonucleic acid. Forty agents were screened for this capability. Nitrous acid, previously reported to be an efficient mutagen for this purpose, increased the frequency of deletion mutations 50-fold in our system. Three others, nitrogen mustard, mitomycin C, and fast neutrons, were shown to increase the frequency of long deletions between five- and eightfold. The remainder were found to be incapable of generating these deletions.