Division of Environmental Dynamics, Graduate School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533, Japan.
Department of Ecosystem Studies, Faculty of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533, Japan.
Parasitol Int. 2023 Feb;92:102682. doi: 10.1016/j.parint.2022.102682. Epub 2022 Sep 22.
Echinoparyphium aconiatum (Digenea: Echinostomatidae) is an intestinal parasite of anatid and snail-eating birds. In Eurasia, it is also common in lymnaeid snails, which may serve as the first and second intermediate hosts. The systematics of its genus, Echinoparyphium, have long been inadequate, with poor descriptions and extensive synonymy. To provide a basis for developing new genetic markers for studies of the identification and systematics of echinostomatids, the complete Ep. aconiatum mitogenome is described and compared with other digeneans. The circular mt molecule of this species is 14,865 bp in length, with an average A + T content of 64.33%. It contains 12 protein-coding genes and 22 transfer RNA genes. The 3' end of nad4L overlaps the 5' end of nad4 by 40 bp, while the atp8 gene is absent. Twenty-one transfer RNA genes transcribe products with conventional cloverleaf structures, while one transfer RNA gene has unpaired D-arms. Comparative analyses indicate that Echinoparyphium aconiatum is closely related to Echinochasmus japonicus and Echinostoma miyagawai. The phylogenetic results, using our mitochondrial data indicated Ep. aconiatum as a sister taxon of Hypoderaeum conoideum in a monophyletic clade. Our data and analyses serve as the first representative sequenced mt genome from genus Echinoparpyhium, providing additional markers to clarify the taxonomic position of Ep. aconiatum.
棘口吸虫属（Digenea：Echinostomatidae）是鸭和食蜗牛鸟类的肠道寄生虫。在欧亚大陆，它也常见于圆口螺科蜗牛，后者可能是其第一和第二中间宿主。棘口属的系统分类长期以来一直不充分，描述不完善且存在广泛的同物异名。为了为研究棘口科寄生虫的鉴定和系统发育开发新的遗传标记提供基础，本文描述并比较了棘口属棘口吸虫的完整线粒体基因组。该物种的圆形 mt 分子长 14865bp，平均 A+T 含量为 64.33%。它包含 12 个蛋白质编码基因和 22 个转移 RNA 基因。nad4L 的 3'端与 nad4 的 5'端重叠 40bp，而 atp8 基因缺失。21 个转移 RNA 基因转录具有常规三叶草结构的产物，而一个转移 RNA 基因的 D 臂未配对。比较分析表明，棘口吸虫属与日本棘口吸虫和曼氏棘口吸虫关系密切。基于我们的线粒体数据的系统发育结果表明，棘口吸虫属与 Hypoderaeum conoideum 是一个单系类群中的姐妹分类群。我们的数据和分析为棘口属的第一个代表序列线粒体基因组提供了更多的标记，以阐明棘口吸虫属的分类地位。
