de la Haba Rafael R, Minegishi Hiroaki, Kamekura Masahiro, Shimane Yasuhiro, Ventosa Antonio
Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain.
Department of Applied Chemistry, Faculty of Science and Engineering, Toyo University, Kawagoe, Japan.
Front Microbiol. 2021 Oct 7;12:740909. doi: 10.3389/fmicb.2021.740909. eCollection 2021.
The haloarchaeal genera and were described almost simultaneously by two different research groups and some strains studied separately were described as different species of these genera. Furthermore, the description of additional species were assigned to either or , mainly on the basis of the phylogenetic comparative analysis of single genes (16S rRNA gene and more recently gene), but these species were not adequately separated or assigned to the corresponding genus. Some studies suggested that the species of these two genera should be unified into a single genus, while other studies indicated that the genera should remain but some of the species should be reassigned. In this study, we have sequenced or collected the genomes of the type strains of species of and and we have carried out a comparative genomic analysis in order to clarify the controversy related to these two genera. The phylogenomic analysis based on the comparison of 525 translated single-copy orthologous genes and the Overall Genome Relatedness Indexes (i.e., AAI, POCP, ANI, and dDDH) clearly indicate that the species , , , , , , and should be transferred to the genus , as , , , , , , and , respectively. On the contrary, the species , , and will remain as the only representative species of the genus . Besides, the species should be reclassified as a member of the genus , as . At the species level, and should be considered as a later heterotypic synonyms of the species () and () , respectively. Synteny analysis and phenotypic features also supported those proposals.
嗜盐古菌属和几乎是由两个不同的研究小组同时描述的，一些分别研究的菌株被描述为这些属的不同物种。此外，其他物种的描述主要基于单个基因（16S rRNA基因以及最近的基因）的系统发育比较分析而被归入或，但这些物种没有得到充分的区分或归入相应的属。一些研究表明这两个属的物种应统一为一个属，而其他研究则表明这两个属应保留，但部分物种应重新分类。在本研究中，我们对和属物种的模式菌株的基因组进行了测序或收集，并进行了比较基因组分析，以澄清与这两个属相关的争议。基于525个翻译后的单拷贝直系同源基因比较和全基因组相关性指数（即AAI、POCP、ANI和dDDH）的系统基因组分析清楚地表明，物种、、、、、、应分别作为、、、、、、转移到属。相反，物种、和将作为属仅有的代表性物种保留。此外，物种应重新分类为属的成员，即。在物种水平上，和应分别被视为物种（）和（）的晚出异名。共线性分析和表型特征也支持这些提议。
