黄颡单尾虫(粘体门,双壳目)的重描述及基于28S rDNA和ITS-5.8S序列的系统地位分析  

REDESCRIPTION OF UNICAUDA PELTEOBAGRUS MA,1998 (MYXOZOA,BIVALVULIDA),WITH PHYLOGENIC ANALYSIS INFERRED FROM 28S RDNA ANDITS-5.8S SEQUENCE DATA

作　　者：董江丽[1] 赵元莙[1] 唐发辉[1] 索栋[1] 

机构地区：[1]动物生物学重庆市重点实验室重庆师范大学,重庆400047

出　　处：《动物分类学报》2011年第1期84-92,共9页Acta Zootaxonomica Sinica

基　　金：国家自然科学基金项目资助(30570221)

摘　　要：采用形态分类学方法与以28S rDNA和ITS-5.8S序列为基础的分子系统学研究方法,对采自嘉陵江重庆市磁器口江段的黄颡单尾虫Unicauda pelteobagrusMa,1998进行了形态学和分子生物学的研究。基于28S rDNA数据探讨了黄颡单尾虫以及单尾虫属与相邻种属粘孢子虫间的系统地位;基于5.8S rDNA数据比较分析了粘孢子虫的系统地位。补充了黄颡单尾虫重庆种群形态学信息和28S rDNA、ITS-5.8S rDNA序列的分子信息。In the present study,the morphology on the Chongqing population of a myxozoa,Unicauda pelteobagrus Ma,1998,collected from the muscle of Pelteobagrus fulvidraco in Jialing River near Ciqikou,Chongqing,China,was investigated. Fresh spores of the present population are oval in front view,13.5 ± 0.67 （12.5-14.5） μm in length,7.4 ± 0.46 （7.0-8.5） μm in width and 38.1 ± 0.55 （31.5-39.5） μm in total length,a single appendage extends posteriorly from the fully developed spore. Two polar capsules,pear-shaped,parallel side by side or one after another arranged in front of spores,containing polar filaments coiled 4-7 turns. Furthermore,the large subunit ribosomal gene （28S rDNA） and ITS-5.8S sequence for Chongqing population were amplified and sequenced. The 28S rDNA contain relatively conservative core segments and 11 highly variable regions designated as divergent domains and the most considerable length variations occurred in D2,D8,and D10 28S rDNA domains. Phylogenetic analyses of the 28S rDNA sequence placed this species in the clade with Myxobolus longisporus （bootstrap =100）. This clade with other species of genera,Henneguya and Myxobolus,grouped into the Myxobolus-Henneguya-Unicauda clade,which indicates that those species could possess a common origin. These data are supported by D2,D8 and D10 length variations and genetic distance,which also implied that Unicauda might be more closely related to Myxobolus. Here,appendage as an only category pointer to identify genera Myxobolus,Henneguya,Unicauda may be incomplete. We compared ITS-1 and ITS-2 sequence of 4 species,viz. Ceratomyxa shasta,Kudoa thyrsites,Myxobolus cerebralis and U. pelteobagrus from the GenBank. The ITS-1 and ITS-2 sequences exist a large variation,so it is much more suitable for discrimination for those lower taxa and their systematic reconstruction. On the contrary,5.8S rDNA is so conservative that it can be used to construct phylogenetic trees for relatively higher taxa. Some species of class Trematoda,class Nematoda,genu

关 键 词：黄颡单尾虫 分类学 28S RDNA ITS-5.8S RDNA 

分 类 号：Q959[生物学—动物学]