PDF(Pubmed)
Abstract：
Human acanthocephaliasis is a rare parasitic zoonosis mainly caused by acanthocephalans belonging to the genera Acanthocephalus, Bolbosoma, Corynosoma, Macracanthorhynchus, and Moniliformis. In the present paper, the juveniles of Bolbosoma nipponicum Yamaguti, 1939 collected from the northern fur seal Callorhinus ursinus (Linnaeus) (Mammalia: Carnivora) in Alaska, USA were precisely identified based on morphological characters and genetic data. Their detailed morphology was studied using light and, for the first time, scanning electron microscopy. The molecular characterization of the nuclear genes [small ribosomal subunit (18S) and large ribosomal subunit (28S)] and the mitochondrial cytochrome c oxidase subunit 1 (cox1) sequence data of B. nipponicum are provided for the first time. Moreover, in order to clarify the phylogenetic relationships of the genus Bolbosoma and the other genera in the family Polymorphidae, phylogenetic analyses were performed integrating different nuclear (18S + ITS+28S) and mitochondrial (cox1) sequence data using maximum likelihood (ML) and Bayesian inference (BI). The phylogenetic results showed that Bolbosoma has a sister relationship with Corynosoma, and also revealed that Southwellina is sister to Ibirhynchus + Hexaglandula. Our molecular phylogeny also indicated a possible host-switch pattern during the evolution of the polymorphid acanthocephalans. The ancestors of polymorphid acanthocephalans seem to have originally parasitized fish-eating waterfowl in continental habitats, then extended to fish-eating marine birds in brackish water and marine habitats, and finally, opportunistically infected the marine mammals.
摘要：
人类棘头虫病是一种罕见的寄生虫人畜共患病，主要由属于棘头菌属的棘头菌引起。Bolbosoma,Corynosoma,Macracanthorhynchus,和Moniliformis.在本论文中，日本BolbosomaYamaguti的少年，1939年从阿拉斯加的北部海豹Callorhinusursinus（Linnaeus）（哺乳动物：食肉动物）收集，根据形态特征和遗传数据对美国进行了精确识别。他们的详细形态是用光和研究，第一次,扫描电子显微镜。首次提供了日本黄曲霉的核基因[小核糖体亚基（18S）和大核糖体亚基（28S）]和线粒体细胞色素c氧化酶亚基1（cox1）序列数据。此外，为了阐明Bolbosoma属和多科其他属的系统发育关系，使用最大似然（ML）和贝叶斯推断（BI）进行系统发育分析，整合不同的核（18SITS28S）和线粒体（cox1）序列数据。系统发育结果表明，Bolbosoma与Corynosoma有姐妹关系，还透露Southwellina是Ibirhynchus+Hexaglandula的妹妹。我们的分子系统发育还表明，在多形虫的进化过程中，可能存在宿主开关模式。多形虫的祖先似乎最初在大陆栖息地寄生了食鱼水禽，然后扩展到咸水和海洋栖息地中的食鱼海洋鸟类，最后，机会性地感染了海洋哺乳动物。
