Genomic study of a novel magnetotactic Alphaproteobacteria uncovers the multiple ancestry of magnetotaxis
Genomic study of a novel magnetotactic Alphaproteobacteria uncovers the multiple ancestry of magnetotaxis
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DOI：
10.1111/1462-2920.14364
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发表时间：
2018-10
影响因子：
5.1
通讯作者：
C. Monteil;G. Perrière;N. Menguy;N. Ginet;Béatrice Alonso;Nicolas Waisbord;S. Cruveiller;D. Pignol
中科院分区：
文献类型：
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作者：
C. Monteil;G. Perrière;N. Menguy;N. Ginet;Béatrice Alonso;Nicolas Waisbord;S. Cruveiller;D. Pignol
趋磁细菌(MTB)适应其环境的生态和进化过程多年来一直是一个争论的问题。正在进行的表征它们的努力正在逐步有助于理解这些过程，包括负责生物矿化的遗传和分子机制。尽管有许多与培养无关的结核分枝杆菌特性，主要是在变形杆菌门中，但由于其复杂的生长条件，在培养中分离出的物种很少。在这里，我们报道了从法国马赛地中海分离到的一种新的趋磁、嗜氧和化学有机异养细菌：Candidatus Terasakiella Magnetica菌株PR-1，它属于一个没有趋磁亲缘关系的阿尔法蛋白细菌属。通过比较该结核分枝杆菌与近亲的形态和全基因组鸟枪序列，我们得到了进一步的证据，先前研究表明，甲型变形杆菌中磁小体基因的明显垂直祖先隐藏了更复杂的进化历史，包括在磁螺旋菌、磁弧菌和磁旋体属出现之前和之后的水平基因转移和/或复制事件。一项基因组规模的比较基因组学分析确定了几个额外的候选功能和基因，这些功能和基因可能与这类细菌中的结核分枝杆菌的生活方式具体相关。
Ecological and evolutionary processes involved in magnetotactic bacteria (MTB) adaptation to their environment have been a matter of debate for many years. Ongoing efforts for their characterization are progressively contributing to understand these processes, including the genetic and molecular mechanisms responsible for biomineralization. Despite numerous culture-independent MTB characterizations, essentially within the Proteobacteria phylum, only few species have been isolated in culture because of their complex growth conditions. Here, we report a newly cultivated magnetotactic, microaerophilic and chemoorganoheterotrophic bacterium isolated from the Mediterranean Sea in Marseille, France: Candidatus Terasakiella magnetica strain PR-1 that belongs to an Alphaproteobacteria genus with no magnetotactic relative. By comparing the morphology and the whole genome shotgun sequence of this MTB with those of closer relatives, we brought further evidence that the apparent vertical ancestry of magnetosome genes suggested by previous studies within Alphaproteobacteria hides a more complex evolutionary history involving horizontal gene transfers and/or duplication events before and after the emergence of Magnetospirillum, Magnetovibrio and Magnetospira genera. A genome-scale comparative genomics analysis identified several additional candidate functions and genes that could be specifically associated to MTB lifestyle in this class of bacteria.