Bello Sarah, Rudra Bashudev, Schellhorn Herb E
Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, L8N 3Z5, Canada.
Department of Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada.
Int J Syst Evol Microbiol. 2025 May;75(5). doi: 10.1099/ijsem.0.006757.
The genus , created by the reclassification of specific deep-branching species, exhibits polyphyletic branching. The Genome Taxonomy Database (GTDB) also assigns species into two families and three genera. To clarify the evolutionary relationships and classification of species, we report detailed investigations using phylogenomic and molecular signature-based approaches. In phylogenomic trees, species are distributed within two family-level lineages. One of these clades, containing the type species (viz. ), represents the genus , groups within the family . Ten novel conserved signature indels (CSIs) identified in this study are specific for this clade, providing a robust means for the differentiation of the emended genus . The remaining species form a separate family-level clade, designated as f_HBI72195 in the GTDB. Within this clade, all species except form a robust clade designated as clade -2 in our work and g__A in the GTDB. We have also identified 15 novel CSIs specific to this clade. As the clade -2 is distinct from , we propose transferring species from this clade into a new genus, gen. nov. The species branches distinctly from other species, and the GTDB considers it a novel genus (g_BR). Six newly identified CSIs are specific to this species, and we are proposing the transfer of this species into a new genus, gen. nov. Two additional identified CSIs are shared by members of the novel family-level taxon (f_HBI72195) comprising the proposed genera and , for which we are proposing the name fam. nov. Lastly, the results presented here also show that '' and '' are later heterotypic synonyms of . These changes, which reliably depict the evolutionary relationships among species, should be helpful in future studies of these organisms.
该属是通过对特定深分支物种的重新分类而创建的，呈现出多系分支。基因组分类数据库（GTDB）也将该物种归入两个科和三个属。为了阐明该物种的进化关系和分类，我们报告了使用系统基因组学和基于分子特征的方法进行的详细研究。在系统基因组树中，该物种分布在两个科级谱系内。其中一个分支包含模式种（即 ），代表该属，属于科内的类群。本研究中鉴定出的10个新的保守特征插入缺失（CSIs）是该分支特有的，为修订后的属的区分提供了有力手段。其余的该物种形成一个单独的科级分支，在GTDB中指定为f_HBI72195。在这个分支内，除 外的所有物种形成一个稳健的分支，在我们的工作中指定为分支-2，在GTDB中为g__A。我们还鉴定出了15个特定于该分支的新CSIs。由于分支-2与 不同，我们建议将该分支中的物种转移到一个新属，新属。物种 与其他该物种明显分支，GTDB认为它是一个新属（g_BR）。六个新鉴定的CSIs是该物种特有的，我们建议将该物种转移到一个新属，新属。另外两个鉴定出的CSIs由包含提议的属 和 的新科级分类单元（f_HBI72195）的成员共享，我们为此提议命名为新科。最后，这里呈现的结果还表明“ ”和“ ”是 的晚出异名。这些变化可靠地描绘了该物种之间的进化关系，应该有助于未来对这些生物的研究。
