尼氏单极虫(粘体门,双壳目)重描述及基于18S rDNA系统地位分析  

MORPHOLOGICAL REDESCRIPTION OF THELOHANELLUS NIKOLSKII ACHMEROV, 1955 (MYXOZOA, BIVALVULIDA) AND PHYLOGENIC ANALYSIS OF THELOHANELLUS NIKOLSKII INFERRED FROM 18S RDNA

作　　者：索栋[1] 赵元莙[1] 

机构地区：[1]重庆市动物生物学重点实验室,重庆师范大学,重庆400047

出　　处：《动物分类学报》2010年第1期90-95,共6页Acta Zootaxonomica Sinica

基　　金：国家自然科学基金项目(30570221);重庆市自然科学基金重点项目(CSTC-2006BA1019)

摘　　要：采用常规细胞学方法与18S rDNA序列比较的方法,对采自于重庆市嘉陵江段的粘孢子虫,尼氏单极虫Thelohanellus nikolskii进行了形态学和分子生物学的研究,此为首次在我国长江流域检获尼氏单极虫。本文在补充了尼氏单极虫中国种群18S rDNA序列信息的分析、比较基础上,探讨了该虫与相邻种属的系统关系,佐证了其分类学位置。In present paper, the morphological data on Chinese population of Thelohanellus nikolskii collected from the fin of Cyprinus carpio of Yangtze River in Chongqing area of Chinese mainland was recorded. Myxosporeans were elongated elliptic with bluntly rounded anterior and posterior end in valvular view in shape, measuring 15.5 ±0.5 （14.4-16.7 ）μm long × 8.7±0.6 （7.3-9.6）μm wide × 7.9 ± 0.4 （7.3-8.7） μm thick. One polar capsule is more or less round in shape, measuring 6.5 ±0.4 （5.5-7.4）μm long × 5.5 ± 0.4 （4.7-6.6）μm wide, containing polar filaments coiled 6-8 turns. The small subunit ribosomal DNA （SSU rDNA） for Chinese population of T. nikolskii was amplified and sequenced. The Chinese population of T. nikolskii has a high similarity （99%） in SSU rDNA with the Hungarian population of the species. Phylogentically, both Chinese population and Hungarian population of T. nikolskii are most closely related to T. wuhanensis, T. hovorkae and T. kitauei within a clade composed entirely of Thelohanellus species. These data further support nonmonophyly of genus within a larger clade composed almost entirely of skin and gill parasites infecting freshwater fishes. Here, tissue specificity is also discussed as an important factor in the evolution of myxozoans. Furthermore, according to the morphologic features on the spore, T. nikolskii and T. dogieli were different from each other in the shape, and these two species are valid species, respectively. T. nikolskii is the first record in Chongqing.

关 键 词：尼氏单极虫 分类学 18S RDNA 

分 类 号：Q959[生物学—动物学] Q953