Uzun Maria, Koziaeva Veronika, Dziuba Marina, Leão Pedro, Krutkina Maria, Grouzdev Denis
Skryabin Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia.
Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.
Front Microbiol. 2022 Aug 1;13:945734. doi: 10.3389/fmicb.2022.945734. eCollection 2022.
Magnetosome synthesis in magnetotactic bacteria (MTB) is regarded as a very ancient evolutionary process that dates back to deep-branching phyla. Magnetotactic bacteria belonging to one of such phyla, , contain the classical genes for the magnetosome synthesis (e.g., , ) and genes, which were considered to be specific for this group. However, the recent discovery of genes in MTB from the phylum has raised several questions about the inheritance of these genes in MTB. In this work, three new genes containing MTB genomes affiliated with and were obtained. By applying reconciliation with these and the previously published MTB genomes, we demonstrate that the last common ancestor of all was most likely not magnetotactic as assumed previously. Instead, our findings suggest that the genes for magnetosome synthesis were transmitted to the phylum by horizontal gene transfer (HGT), which is the first case of the interphylum transfer of magnetosome genes detected to date. Furthermore, we provide evidence for the HGT of magnetosome genes from the to the family within Thus, our results imply a more significant role of HGT in the MTB evolution than deemed before and challenge the hypothesis of the ancient origin of magnetosome synthesis.
趋磁细菌（MTB）中的磁小体合成被认为是一个非常古老的进化过程，可以追溯到分支较深的门类。属于此类门类之一的趋磁细菌含有磁小体合成的经典基因（例如， ）和 基因，这些基因被认为是该类群特有的。然而，最近在来自 门类的趋磁细菌中发现 基因，引发了关于这些基因在趋磁细菌中遗传的几个问题。在这项工作中，获得了三个与 和 相关的含有趋磁细菌基因组的新 基因。通过将这些基因与之前发表的趋磁细菌基因组进行比对，我们证明所有 的最后一个共同祖先很可能不像之前假设的那样具有趋磁性。相反，我们的研究结果表明，磁小体合成基因是通过水平基因转移（HGT）传递到 门类的，这是迄今为止检测到的磁小体基因在门间转移的首例。此外，我们提供了磁小体基因从 到 科内水平基因转移的证据。因此，我们的结果表明水平基因转移在趋磁细菌进化中的作用比之前认为的更为重要，并挑战了磁小体合成起源古老的假说。
