Centre of Parasitology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskii prospect, 33, Moscow, Russian Federation, 119071.
Laboratory of Mammalian Microevolution, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskii prospect, 33, Moscow, Russian Federation, 119071.
Parasitol Res. 2021 Jun;120(6):2017-2030. doi: 10.1007/s00436-021-07134-7. Epub 2021 Mar 27.
The genetic diversity of Syphacia nematodes (intestinal parasites of rodents) was studied in the hybrid zone of two sister species of common voles, Microtus arvalis and Microtus obscurus, in the Oka River valley, east of Moscow. Syphacia nematodes of other rodent species (Microtus rossiaemeridionalis, Alexandromys oeconomus, Sylvaemus uralensis, and Apodemus agrarius) that inhabit the area were also studied. Phylogenetic trees for the studied nematodes were inferred from the analysis of nuclear ITS1+5.8S+ITS2, LSU rDNA, and mitochondrial CO1 gene partial sequences. Syphacia nematodes of the studied area form three well-defined clades in the phylogenetic tree of this genus. Morphological analysis revealed similarities between the obtained sequences with those of known Syphacia species from the GenBank database, which enabled identifying these three clades up to the species level: S. montana, S. agraria, and S. frederici. Russian haplotypes of Syphacia are different from West European and East Asian haplotypes with pronounced genetic distances. A high level of specificity was reported for two of these three species (S. frederici, only in Sylvaemus uralensis; S. agraria, only in Apodemus agrarius). S. montana was found in different species of voles. Remarkably, S. montana specimens from M. arvalis and M. obscurus were genetically uniform, while S. montana, specimens from hybrids between these two species formed a separate clade distant from those originating from non-hybridised hosts.
在莫斯科以东奥卡河谷的两种亲缘关系密切的普通田鼠（黑线姬鼠和黑线仓鼠）的杂交区，研究了肠道寄生线虫（Syphacia nematodes）的遗传多样性。还研究了该地区其他啮齿动物物种（东方田鼠、黑线仓鼠、黑线毛足鼠和黑线姬鼠）的Syphacia 线虫。从核 ITS1+5.8S+ITS2、LSU rDNA 和线粒体 CO1 基因部分序列的分析中推断出所研究线虫的系统发育树。研究区域的 Syphacia 线虫在该属的系统发育树中形成了三个明确的分支。形态学分析显示，获得的序列与 GenBank 数据库中已知的 Syphacia 物种序列相似，这使得能够将这三个分支识别到种的水平：S. montana、S. agraria 和 S. frederici。俄罗斯的 Syphacia 单倍型与西欧和东亚的单倍型有明显的遗传距离不同。这三个物种中的两个（仅在黑线毛足鼠中发现的 S. frederici 和仅在黑线姬鼠中发现的 S. agraria）表现出高度的特异性。S. montana 存在于不同的田鼠物种中。值得注意的是，来自 M. arvalis 和 M. obscurus 的 S. montana 标本在遗传上是一致的，而来自这两个物种杂交种的 S. montana 标本形成了一个与源自非杂交宿主的标本分开的分支。
