CHLORATE TOXICITY IN ASPERGILLUS-NIDULANS - SELECTION AND CHARACTERIZATION OF CHLORATE RESISTANT MUTANTS
CHLORATE TOXICITY IN ASPERGILLUS-NIDULANS - SELECTION AND CHARACTERIZATION OF CHLORATE RESISTANT MUTANTS
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DOI：
10.1038/hdy.1976.24
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发表时间：
1976-01-01
期刊：
影响因子：
3.8
通讯作者：
COVE, DJ
中科院分区：
文献类型：
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作者：
COVE, DJ
至少10个基因的突变可导致芽孢杆菌对氯酸盐的抗性。其中7个基因的突变也导致无法利用硝酸盐作为氮源。所获得的各种类型的抗性突变体以不同的比例出现，这取决于是否采用诱变处理，也取决于采用哪种氮源进行选择。诱变剂的主要作用是在不使用诱变剂的情况下，与使用n -甲基-n " -硝基-n -亚硝基胍处理后相比，niaD基因（硝酸还原酶结构基因）的突变更为常见。这可能与发现涉及niaD基因的缺失在自发niaD突变体样本中相对更常见有关。其中一些缺失延伸到邻近的niiA基因，即亚硝酸盐还原酶的结构基因。所使用的选择程序旨在避免偏向于任何特定的氯酸盐抗性表型。即使存在偏倚，这些也不能解释某些具有明显相同氯酸盐抗性表型的抗性类别在N源与N源之间的比例差异。
Mutation in at least 10 genes can result in chlorate resistance in A. nidulans. Mutation in 7 of these genes also results in the inability to use nitrate as a N source. The various classes of resistant mutant obtained occur in different proportions, depending on whether or not a mutagenic treatment is employed, and also on which N source is used for selection. The principal effect of mutagen arises because mutations in the niaD gene, the nitrate reductase structural gene, are relatively much commoner when no mutagen is used than after treatment with N-methyl-N''-nitro-N-nitrosoguanidine. This may be connected with the finding that deletions involving the niaD gene are relatively more common among samples of spontaneous niaD mutants. Some of these deletions extend to the neighboring niiA gene, the structural gene for nitrite reductase. The selection procedures used were designed to avoid bias in favor of any particular chlorate resistant phenotype. Even if biases existed, these could not account for the variation found from N source to N source in the proportions of certain resistant classes having apparently identical chlorate resistance phenotypes.