Classifying mutagens as to their specificity in causing the six possible transitions and transversions: a simple analysis using the Salmonella mutagenicity assay.
Classifying mutagens as to their specificity in causing the six possible transitions and transversions: a simple analysis using the Salmonella mutagenicity assay.
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根据诱变剂引起六种可能的转变和颠换的特异性进行分类：使用沙门氏菌致突变性测定的简单分析。
DOI：
10.1002/em.2860080103
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Ames,BN
中科院分区：
文献类型：
--
作者：
Levin,DE;Ames,BN
用于检测碱基取代突变的标准沙门氏菌测试菌株携带hisG428ochre突变（TA102和TA104）和hisG46错义突变（TA100）。这些突变可以通过其突变位点或外源抑制基因座的碱基变化来恢复。导致这些突变的每一类回复体的碱基变化已经被鉴定，并且已经开发出简单的表型筛选来区分它们。基因外抑制基因座上的回复体与组氨酸基因座上的回复体的区别在于它们对抑制性组氨酸类似物的敏感性。 hisG428 的四个赭色抑制基因座因其支持噬菌体 P22 无义突变体生长的能力而著称。这些筛选是快速而简单的系统的基础，该系统用于使用包含hisG428和hisG46的测试菌株来确定诱变剂的碱基取代特异性。已鉴定出针对六种可能的碱基变化（转换和颠换）中每一种的特异性诊断诱变剂。使用这些诊断诱变剂，已经开发出另外两种菌株，每种菌株均通过单碱基取代突变特异性恢复，以提供至少两个基因座来检测每种类型的碱基变化。该系统能够提供有关各种 DNA 修复背景中突变特异性的详细信息，这将有助于进一步阐明诱变和 DNA 修复的机制。
The standardSalmonellatester strains used to detect base substitution mutations carry thehisG428ochre mutation (TA102 and TA104) and thehisG46missense mutation (TA100). These mutations can be reverted by base changes at their mutanthisloci or at extragenic suppressor loci. The base changes resulting in each class of revertants of these mutations have been identified, and simple phenotypic screens have been developed to distinguish among them. Revertants at extragenic suppressor loci are distinguished from those at thehisloci by their sensitivity to inhibitory histidine analogs. The four ochre suppressor loci ofhisG428are distinguished by their ability to support growth of nonsense mutants of phage P22. These screens are the basis for a rapid and simple system for determining the base substitution specificity of mutagens usinghisG428‐ andhisG46‐containing tester strains. Diagnostic mutagens specific for each of the six possible base changes (transitions and transversions) have been identified. Using these diagnostic mutagens, two additional strains, each specifically reverted by a single base substitution mutation, have been developed to provide a minimum of two loci at which to detect each type of base change. The ability of this system to provide detailed information about mutational specificity in a variety of DNA repair backgrounds will allow further elucidation of the mechanisms of mutagenesis and DNA repair.