Du Haijian, Zhang Wenyan, Zhang Wensi, Zhang Weijia, Pan Hongmiao, Pan Yongxin, Bazylinski Dennis A, Wu Long-Fei, Xiao Tian, Lin Wei
Key Laboratory for Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
mSystems. 2019 Oct 29;4(5):e00315-19. doi: 10.1128/mSystems.00315-19.
The evolution of microbial magnetoreception (or magnetotaxis) is of great interest in the fields of microbiology, evolutionary biology, biophysics, geomicrobiology, and geochemistry. Current genomic data from magnetotactic bacteria (MTB), the only prokaryotes known to be capable of sensing the Earth's geomagnetic field, suggests an ancient origin of magnetotaxis in the domain Vertical inheritance, followed by multiple independent magnetosome gene cluster loss, is considered to be one of the major forces that drove the evolution of magnetotaxis at or above the class or phylum level, although the evolutionary trajectories at lower taxonomic ranks (e.g., within the class level) remain largely unstudied. Here we report the isolation, cultivation, and sequencing of a novel magnetotactic spirillum belonging to the genus ( sp. strain SH-1) within the class The complete genome sequence of sp. strain SH-1 revealed an unexpected duplication event of magnetosome genes within the operon, a group of genes essential for magnetosome biomineralization and magnetotaxis. Intriguingly, further comparative genomic analysis suggests that the duplication of genes is a common feature in the genomes of alphaproteobacterial MTB. Taken together, with the additional finding that gene duplication appears to have also occurred in some magnetotactic members of the , our results indicate that gene duplication plays an important role in the evolution of magnetotaxis in the and perhaps the domain A diversity of organisms can sense the geomagnetic field for the purpose of navigation. Magnetotactic bacteria are the most primitive magnetism-sensing organisms known thus far and represent an excellent model system for the study of the origin, evolution, and mechanism of microbial magnetoreception (or magnetotaxis). The present study is the first report focused on magnetosome gene cluster duplication in the , which suggests the important role of gene duplication in the evolution of magnetotaxis in the and perhaps the domain A novel scenario for the evolution of magnetotaxis in the is proposed and may provide new insights into evolution of magnetoreception of higher species.
微生物磁受体（或趋磁作用）的进化在微生物学、进化生物学、生物物理学、地球微生物学和地球化学领域备受关注。趋磁细菌（MTB）是已知唯一能够感知地球地磁场的原核生物，目前来自趋磁细菌的基因组数据表明趋磁作用起源古老，在垂直遗传之后，多个独立的磁小体基因簇丢失被认为是驱动纲或门及以上水平趋磁作用进化的主要力量之一，尽管较低分类等级（如纲内）的进化轨迹仍 largely 未被研究。在此，我们报告了一株属于 纲 属（ sp. 菌株 SH - 1）的新型趋磁螺旋菌的分离、培养和测序。 sp. 菌株 SH - 1 的完整基因组序列揭示了磁小体基因在 操纵子内意外的重复事件， 操纵子是一组对磁小体生物矿化和趋磁作用至关重要的基因。有趣的是，进一步的比较基因组分析表明， 基因的重复是α - 变形菌纲趋磁细菌基因组中的一个共同特征。综合来看，再加上另外一个发现，即基因重复似乎也发生在 纲的一些趋磁成员中，我们的结果表明基因重复在 纲以及可能在 域的趋磁作用进化中发挥着重要作用。多种生物能够为了导航目的感知地磁场。趋磁细菌是迄今为止已知的最原始的磁感生物，是研究微生物磁受体（或趋磁作用）的起源、进化和机制的优秀模型系统。本研究是首次聚焦于 纲磁小体基因簇重复的报告，这表明基因重复在 纲以及可能在 域的趋磁作用进化中具有重要作用。提出了 纲趋磁作用进化的新情景，可能为高等物种磁受体的进化提供新见解。
