Mosaic DNA Imports with Interspersions of Recipient Sequence after Natural Transformation of Helicobacter pylori
Mosaic DNA Imports with Interspersions of Recipient Sequence after Natural Transformation of Helicobacter pylori
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DOI：
10.1371/journal.pone.0003797
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发表时间：
2008-11-24
期刊：
影响因子：
3.7
通讯作者：
Suerbaum, Sebastian
中科院分区：
文献类型：
--
作者：
Kulick, Stefan;Moccia, Claudia;Suerbaum, Sebastian
幽门螺杆菌定植于一半人口的胃粘膜，引起胃炎、溃疡和癌症。H. pylori在一个胃与多个H. pylori菌株产生广泛的等位基因多样性。我们开发了一种体外转化方案来研究H.幽门。输入片段的平均长度取决于供体和受体菌株的组合，在1294 bp和3853 bp之间变化。在约10%的重组克隆中，供体DNA的输入片段被受体的短散布序列（ISR）中断，平均长度为82 bp。对18个候选基因进行失活，以鉴定参与控制输入长度和ISR产生的基因。失活的抗突变体糖基化酶MutY增加了进口的长度，但没有对ISR频率的显着影响。mutY的过表达强烈增加ISR的频率，表明MutY，而不是必不可少的ISR形成，是至少一个ISR生成途径的一部分。ISR在H.幽门螺杆菌增加了等位基因多样性，并促成了该病原体独特的低连锁不平衡特征。
Helicobacter pylori colonizes the gastric mucosa of half of the human population, causing gastritis, ulcers, and cancer. H. pylori is naturally competent for transformation by exogenous DNA, and recombination during mixed infections of one stomach with multiple H. pylori strains generates extensive allelic diversity. We developed an in vitro transformation protocol to study genomic imports after natural transformation of H. pylori. The mean length of imported fragments was dependent on the combination of donor and recipient strain and varied between 1294 bp and 3853 bp. In about 10% of recombinant clones, the imported fragments of donor DNA were interrupted by short interspersed sequences of the recipient (ISR) with a mean length of 82 bp. 18 candidate genes were inactivated in order to identify genes involved in the control of import length and generation of ISR. Inactivation of the antimutator glycosylase MutY increased the length of imports, but did not have a significant effect on ISR frequency. Overexpression of mutY strongly increased the frequency of ISR, indicating that MutY, while not indispensable for ISR formation, is part of at least one ISR-generating pathway. The formation of ISR in H. pylori increases allelic diversity, and contributes to the uniquely low linkage disequilibrium characteristic of this pathogen.