mgpB and mgpC sequence diversity in Mycoplasma genitalium is generated by segmental reciprocal recombination with repetitive chromosomal sequences
mgpB and mgpC sequence diversity in Mycoplasma genitalium is generated by segmental reciprocal recombination with repetitive chromosomal sequences
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DOI：
10.1111/j.1365-2958.2007.05898.x
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发表时间：
2007-10-01
影响因子：
3.6
通讯作者：
Totten, Patricia A.
中科院分区：
文献类型：
--
作者：
Iverson-Cabral, Stefanie L.;Astete, Sabina G.;Totten, Patricia A.
生殖支原体与男性和女性的性传播感染有关，如果不治疗，可能会持续存在，这表明存在促进免疫逃避的机制。约4%的有限M。生殖器基因组包含称为MgPar区的重复序列，其与mgpB和mgpC具有同源性，其编码与附着相关的抗原蛋白。我们以前已经表明，mgpB序列在一个单一的M菌株内变化。与mgpB和MgPar序列之间的重组一致的模式（Iverson-Cabral等）。在目前的研究中，我们表明，mgpC异质性同样发生在模式菌株，G-37（T），在体外培养和宫颈标本中收集的持续感染的妇女。在所有情况下，替代mgpC序列指示与MgPar区域的重组。此外，还对单菌落M.含有替代mgpB或mgpC序列的生殖器克隆变体使我们能够证明mgpB和mgpC异质性与供体MgPar区域内的相应变化相关，与相互重组一致。较好定义的抗原变异系统通常由单向基因转换介导，因此在M.通过序列的相互交换，这种生物体在细菌病原体中是独特的。
Mycoplasma genitalium is associated with sexually transmitted infections in men and women that, if untreated, can persist, suggesting that mechanism(s) exist to facilitate immune evasion. Approximately 4% of the limited M. genitalium genome contains repeat sequences termed MgPar regions that have homology to mgpB and mgpC, which encode antigenic proteins associated with attachment. We have previously shown that mgpB sequences vary within a single strain of M. genitalium in a pattern consistent with recombination between mgpB and MgPar sequences (Iverson-Cabral et al.). In the current study, we show that mgpC heterogeneity similarly occurs within the type strain, G-37(T), cultured in vitro and among cervical specimens collected from a persistently infected woman. In all cases, alternative mgpC sequences are indicative of recombination with MgPar regions. Additionally, the isolation of single-colony M. genitalium clonal variants containing alternative mgpB or mgpC sequences allowed us to demonstrate that mgpB and mgpC heterogeneity is associated with corresponding changes within donor MgPar regions, consistent with reciprocal recombination. Better-defined systems of antigenic variation are typically mediated by unidirectional gene conversion, so the generation of genetic diversity observed in M. genitalium by the mutual exchange of sequences makes this organism unique among bacterial pathogens.