The simple sequence contingency loci of Haemophilus influenzae and Neisseria meningitidis
The simple sequence contingency loci of Haemophilus influenzae and Neisseria meningitidis
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DOI：
10.1172/jci12557
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发表时间：
2001-03-01
影响因子：
15.9
通讯作者：
Moxon, ER
中科院分区：
文献类型：
--
作者：
Bayliss, CD;Field, D;Moxon, ER
658《临床研究杂志》|2001年3月|第107卷|第6期翻译或改变启动子活性水平。这些基因座的两个特征将它们与其他表型变异机制区分开来。首先，这些基因座的超突变不依赖于经典的重组基因，而不是其他的阶段变化机制，如基因转换、转座和“触发器”。第二，简单序列的可逆性和超变性是由一个或多个重复单元的重复区域的扩展或收缩引起的，因此存在多种可能的“开”和“关”状态。例如，一个或两个重复单元的获得或丢失可能会将阅读框中的On四核苷酸重复序列切换到Off。由于这些突变可能发生在少数世代中，即使在单个克隆的细胞之间，这些基因座也可能表现出高度多态。
658 The Journal of Clinical Investigation| March 2001| Volume 107| Number 6 of translation or changes in the level of promoter activity. Two features of these loci distinguish them from other mechanisms of phenotypic variation. First, the hypermutation of these loci is independent of classic recombination genes, in contrast to other mechanisms of phase variation such as gene conversion, transposition, and “flip-flop.” Second, the reversibility and hypermutability of simple sequences result from expansion or contraction of the repeat tracts by one or more repeat units, such that there are multiple possible “ON” and “OFF” states. For example, the gain or loss of one or two repeat units could switch an ON tetranucleotide repeat tract in a reading frame to OFF. Because these mutations can occur in a small number of generations, these loci can appear highly polymorphic even between cells of a single clone.