Zhang Xi, Shi Ya L, Wang Zhong Q, Duan Jiang Y, Jiang Peng, Liu Ruo D, Cui Jing
Department of Parasitology, School of Basic Medical Sciences, Zhengzhou UniversityZhengzhou, China.
Front Microbiol. 2017 Jul 13;8:1335. doi: 10.3389/fmicb.2017.01335. eCollection 2017.
, also called the oriental eyeworm, is the major etiological agent of human thelaziasis. Cases of thelaziasis have increased in recent years in China. Although this species is of medical importance, the genetics and phylogenetic systematics of are poorly understood. In this study, we first reported three cases of thelaziasis in central China. All clinical isolates were identified as according to morphological characteristics by light microscopy and scanning electron microscopy. Next, complete mitochondrial (mt) genomes for the three . isolates from different geographical locations were fully characterized using an Illumina sequencing platform. In addition, all available mt genomes of spirurid nematodes in GenBank were included to reconstruct the phylogeny and to explore the evolutionary histories of the isolates. The genome features of the . isolates contained 12 PCGs, 22 transfer RNA genes, two ribosomal RNA genes and a major non-coding region. The mtDNA nucleotide sequences of the . isolates from different hosts and different locations were similar. The n6 gene showed high sequence variability among all isolates, which is worth considering for future population genetic studies of . Phylogenetic analyses based on maximum parsimony and Bayesian inference methods revealed close relationships among Thelaziidae, Onchocercidae, Setariidae, Gongylonematidae, Physalopteridae, Dracunculidae, and Philometridae. The monophyly of the isolates from different hosts and distinct geographical locations was confirmed. The entire mt genomes of . presented in this study will serve as a useful dataset for studying the population genetics and phylogenetic relationships of species.
结膜吸吮线虫，也被称为东方眼虫，是人类吸吮线虫病的主要病原体。近年来中国吸吮线虫病病例有所增加。尽管该物种具有医学重要性，但对结膜吸吮线虫的遗传学和系统发育分类学了解甚少。在本研究中，我们首次报道了中国中部的三例吸吮线虫病病例。通过光学显微镜和扫描电子显微镜根据形态特征将所有临床分离株鉴定为结膜吸吮线虫。接下来，使用Illumina测序平台对来自不同地理位置的三株结膜吸吮线虫分离株的完整线粒体（mt）基因组进行了全面表征。此外，还纳入了GenBank中所有可用的旋尾目线虫mt基因组，以重建系统发育并探索分离株的进化历史。结膜吸吮线虫分离株的基因组特征包括12个蛋白质编码基因、22个转运RNA基因、两个核糖体RNA基因和一个主要非编码区。来自不同宿主和不同位置的结膜吸吮线虫分离株的mtDNA核苷酸序列相似。n6基因在所有分离株中显示出高序列变异性，这在未来结膜吸吮线虫的群体遗传学研究中值得考虑。基于最大简约法和贝叶斯推断方法的系统发育分析揭示了吸吮科、盘尾丝虫科、丝状线虫科、筒线虫科、泡翼线虫科、龙线虫科和菲尔线虫科之间的密切关系。确认了来自不同宿主和不同地理位置的结膜吸吮线虫分离株的单系性。本研究中呈现的结膜吸吮线虫完整mt基因组将作为研究结膜吸吮线虫物种群体遗传学和系统发育关系的有用数据集。
