Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada.
Departamento de Microbiologia, ICB, Universidade Federal de Minas Gerais, C.P. 486, Belo Horizonte, MG, Brazil.
Antonie Van Leeuwenhoek. 2020 Jun;113(6):753-762. doi: 10.1007/s10482-020-01395-5. Epub 2020 Feb 25.
The isolation of a single yeast strain in the clade containing Metschnikowia dekortorum, in the Amazon biome of Brazil, incited us to re-examine the species boundaries within the clade. The strain (UFMG-CM-Y6306) was difficult to position relative to neighbouring species using standard barcode sequences (ITS-D1/D2 rRNA gene region). Mating took place freely with α strains of M. bowlesiae, M. dekortorum, and M. similis, but two-spored asci, indicative of a fertile meiotic progeny, were formed abundantly only with certain strains of M. dekortorum. Accordingly, we examined mating success among every phylotype in the clade and constructed a phylogeny based on a concatenation of 100 of the largest orthologous genes annotated in draft genomes. The analyses confirmed membership of the Amazonian isolate in M. dekortorum, but also indicated that the species should be subdivided into two. As a result, we retain three original members of M. dekortorum in the species, together with the new isolate, and reassign six isolates recovered from Mesoamerican lacustrine habitats to Metschnikowia lacustris sp. nov. The type is UWOPS 12-619.2 (isotype CBS 16250). MycoBank: MB 833751.
在巴西亚马逊生物群中，我们分离到一株单酵母菌株，该菌株属于 Metschnikowia dekortorum 进化枝，这促使我们重新审视该进化枝内的物种界限。该菌株（UFMG-CM-Y6306）使用标准的条码序列（ITS-D1/D2 rRNA 基因区域）难以与邻近物种定位。它与 M. bowlesiae、M. dekortorum 和 M. similis 的α菌株自由交配，但只有与某些 M. dekortorum 菌株交配才能形成大量的二倍体子囊，这表明其有可育的减数分裂后代。因此，我们检查了进化枝中每个 phylo 型的交配成功率，并基于注释在草图基因组中的 100 个最大直系同源基因的串联构建了一个系统发育树。分析结果证实了该亚马逊分离株属于 M. dekortorum，但也表明该物种应该分为两个。因此，我们保留了该物种中的三个原始 M. dekortorum 成员，以及新的分离株，并将从中美洲湖泊生境中回收的六个分离株重新分配给 Metschnikowia lacustris sp. nov.。模式是 UWOPS 12-619.2（同型 CBS 16250）。MycoBank：MB 833751。
