College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang Province 163319, PR China.
College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang Province 163319, PR China; College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang Province 163319, PR China.
Infect Genet Evol. 2019 Nov;75:103961. doi: 10.1016/j.meegid.2019.103961. Epub 2019 Jul 10.
Echinostoma miyagawai (Trematoda: Echinostomatidae) is a common parasite of poultry that also infects humans. Es. miyagawai belongs to the "37 collar-spined" or "revolutum" group, which is very difficult to identify and classify based only on morphological characters. Molecular techniques can resolve this problem. The present study, for the first time, determined, and presented the complete Es. miyagawai mitochondrial genome. A comparative analysis of closely related species, and a reconstruction of Echinostomatidae phylogeny among the trematodes, is also presented. The Es. miyagawai mitochondrial genome is 14,416 bp in size, and contains 12 protein-coding genes (cox1-3, nad1-6, nad4L, cytb, and atp6), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and one non-coding region (NCR). All Es. miyagawai genes are transcribed in the same direction, and gene arrangement in Es. miyagawai is identical to six other Echinostomatidae and Echinochasmidae species. The complete Es. miyagawai mitochondrial genome A + T content is 65.3%, and full-length, pair-wise nucleotide sequence identity between the six species within the two families range from 64.2-84.6%. The Es. miyagawai sequences is most similar to Echinostoma caproni. Sequence difference are 15.0-33.5% at the nucleotide level, and 8.6-44.2% at the amino acid level, among the six species, for the 12 protein-coding genes. ATG and TAG are the most common initiation and termination codons, respectively. Twenty of the Es. miyagawai transfer RNA genes transcribe products of the conventional cloverleaf structure, while two of the transfer RNA genes, namely trnS1 and trnS2, have unpaired D-arms. Phylogenetic analyses using our mitochondrial data indicate that Es. miyagawai is closely related to other Echinostomatidae species, except for Echinostoma hortense, which forms a distinct paraphyletic branch, and Echinochasmus japonicus, which is outside the clade containing all other Echinostomatidae species. These phylogenetic results support the elevation of subfamily Echinostomatidae. Our dataset also provides a significant resource of molecular markers to study the taxonomy, population genetics, and systematics of the echinostomatids.
宫脂属（吸虫纲：Echinostomatidae）是一种常见的家禽寄生虫，也感染人类。Es. miyagawai 属于“37 个领棘”或“revolutum”组，仅基于形态特征很难识别和分类。分子技术可以解决这个问题。本研究首次确定并呈现了完整的 Es. miyagawai 线粒体基因组。还对密切相关的物种进行了比较分析，并重建了吸虫纲中的 Echinostomatidae 系统发育。Es. miyagawai 线粒体基因组大小为 14416bp，包含 12 个蛋白编码基因（cox1-3、nad1-6、nad4L、cytb 和 atp6）、22 个转移 RNA 基因（tRNAs）、两个核糖体 RNA 基因（rRNAs）和一个非编码区（NCR）。Es. miyagawai 的所有基因都以相同的方向转录，基因排列与另外六种 Echinostomatidae 和 Echinochasmidae 物种相同。Es. miyagawai 的完整线粒体基因组 A+T 含量为 65.3%，在这两个科的六种物种中，全长、成对核苷酸序列同一性范围为 64.2-84.6%。Es. miyagawai 序列与 Echinostoma caproni 最为相似。在这六个物种的 12 个蛋白编码基因中，核苷酸水平的序列差异为 15.0-33.5%，氨基酸水平的序列差异为 8.6-44.2%。ATG 和 TAG 分别是最常见的起始和终止密码子。20 个 Es. miyagawai 转移 RNA 基因转录出常规三叶草结构的产物，而两个转移 RNA 基因（trnS1 和 trnS2）具有未配对的 D 臂。使用我们的线粒体数据进行的系统发育分析表明，Es. miyagawai 与其他 Echinostomatidae 物种密切相关，除了 Echinostoma hortense，它形成了一个明显的并系分支，而 Echinochasmus japonicus 则不在包含所有其他 Echinostomatidae 物种的分支内。这些系统发育结果支持了亚科 Echinostomatidae 的提升。我们的数据集还为研究 Echinostomatidae 的分类学、种群遗传学和系统发育学提供了重要的分子标记资源。
