Revisiting bacterial phylogeny: Natural and experimental evidence for horizontal gene transfer of 16S rRNA.
Revisiting bacterial phylogeny: Natural and experimental evidence for horizontal gene transfer of 16S rRNA.
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DOI：
10.4161/mge.24210
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发表时间：
2013-01-01
期刊：
影响因子：
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通讯作者：
Miyazaki K
中科院分区：
文献类型：
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作者：
Kitahara K;Miyazaki K
目前用于原核生物系统发育分类的方法主要依赖于细胞中普遍存在的16S rRNA基因的序列。这种方法的理论基础是基于这样的假设，即16S rRNA基因仅垂直遗传，因此是每个物种的固有基因。然而，微生物基因组分析揭示了含有两种类型的rRNA（rrn）操纵子的原核生物物种的存在，这两种类型的操纵子看似不同的起源。也有报道称，一些细菌含有16S rRNA，这些rRNA是来自多个物种的序列的嵌合体。这表明16S rRNA基因发生了水平基因转移（HGT）。此外，最近一项模拟天然HGT过程的HGT实验表明，广泛的外源16S rRNA基因可以转移到大肠杆菌中，包括来自不同系统发育类别的基因（与大肠杆菌16S rRNA基因的最低序列同一性为80.9%）。因此，与复杂性假说相反，该假说认为信息基因很少在物种之间水平转移，16S rRNA偶尔服从HGT。因此，对目前基于16S rRNA基因的原核生物快速鉴定和分类方法的结果应仔细分析和解释。
Current methods used for phylogenetic classification of prokaryotes largely rely on the sequences of 16S rRNA genes that are ubiquitously present in the cell. Theoretical basis of this methodology is based on the assumption that 16S rRNA genes are only vertically inherited and are thus indigenous to each species. However, microbial genomic analysis has revealed the existence of prokaryotic species containing two types of rRNA (rrn) operons of seemingly different origins. It has also been reported that some bacteria contain 16S rRNA that are mosaics of sequences from multiple species. This suggests that horizontal gene transfer (HGT) occurred for 16S rRNA genes. In addition, a recent HGT experiment mimicking the natural HGT process has shown that a wide range of foreign 16S rRNA genes can be transferred into Escherichia coli, including those from different phylogenetic classes (with a minimum sequence identity of 80.9% to the Escherichia coli 16S rRNA gene). Thus, in contrast to the complexity hypothesis that states informational genes are rarely horizontally transferred between species, 16S rRNA is occasionally amenable to HGT. Results of the current method for rapid identification and classification of prokaryotes based on the 16S rRNA gene should thus be carefully analyzed and interpreted.