Spontaneous tandem genetic duplications in Salmonella typhimurium arise by unequal recombination between rRNA (rrn) cistrons.
Spontaneous tandem genetic duplications in Salmonella typhimurium arise by unequal recombination between rRNA (rrn) cistrons.
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鼠伤寒沙门氏菌中的自发串联遗传复制是由 rRNA (rrn) 顺反子之间的不平等重组引起的。
DOI：
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发表时间：
1981
影响因子：
11.1
通讯作者：
J. Roth
中科院分区：
文献类型：
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作者：
P. Anderson;J. Roth
本文描述了一种检测和测量沙门氏菌基因组中自发串联基因重复频率的方法。该方法是基于含有重复的菌株在广义转导杂交中继承单个基因的两个可选择等位基因的能力。该基因的一个等位基因插入可易位的四环素耐药元件Tn10；另一个等位基因是该基因的野生型拷贝。利用这种技术，我们测量了38个染色体位点串联重复的频率和199个独立重复中包含的物质的数量。这些结果表明，在染色体的一个区域，串联复制是特别频繁的事件。这种重复的终点在rRNA （rrn）反式子内，可能是由这些分散的重复序列之间的不平等交叉引起的。这种类型的自发复制存在于多达3%的细菌种群中。初步证据表明，在快速生长的条件下，这种复制可能起着重要的调节作用。我们的分析表明了另一个rRNA反扰子在基因组上的位置。
A method is described to detect and measure the frequency of spontaneous tandem genetic duplications located throughout the Salmonella genome. The method is based on the ability of duplication-containing strains to inherit two selectable alleles of a single gene during generalized transductional crosses. One allele of the gene carries an insertion of the translocatable tetracycline-resistance element Tn10; the other allele is a wild-type copy of that gene. Using this technique, we have measured the frequency of tandem duplications at 38 chromosomal sites and the amount of material included in 199 independent duplications. These results suggest that, in one region of the chromosome, tandem duplications are particularly frequent events. Such duplications have end points within rRNA (rrn) cistrons and probably arise by unequal cross-over between these dispersed repeated sequences. Spontaneously duplications of this type are harbored by as much as 3% of the bacterial population. Preliminary evidence suggests that such duplications may play a significant regulatory role under conditions of rapid growth. Our analysis has suggested the position on the genome of an additional rRNA cistron.