游仆目纤毛虫(纤毛门,旋唇纲)的分子系统学研究  

PHYLOGENETIC STUDIES ON THE ORDER EUPLOTIDA (PROTOZOA,CILIOPHORA,SPIROTRICHEA) INFERRED FROM SS RRNA SEQUENCES

作　　者：郭文波[1,2] 包振民[2] 高珊[1] 宋微波[1] 

机构地区：[1]原生动物学研究室,中国海洋大学,青岛266003 [2]海洋生物遗传学与种质工程实验室,中国海洋大学,青岛266003

出　　处：《动物分类学报》2009年第3期507-512,共6页Acta Zootaxonomica Sinica

基　　金：国家自然科学基金项目(30870264)资助

摘　　要：在最新GenBank分子信息的汇集、分析基础上,利用小亚基单位核糖体RNA基因序列分别构建了最大简约树、距离树、最大似然树及贝叶斯树,对长期存在争议的游仆目纤毛虫的系统关系进行了探讨和修订。工作显示:1)游仆目不是1个单源发生系;2)盘头虫类从游仆目中较早分化出来,呈现与排毛类、寡毛类平行的进化关系;3)腹棘虫科内的腹棘虫和拟游仆虫体现了密切的亲缘关系;4)游仆虫科、舍太虫科、纤虫科在所有分子树中均表现了十分稳定的拓扑结构;5)游仆虫属内可以细分为7个亚类群;6)尾刺虫科在游仆目内分化较早,支持前人有关其在系统演化时序中处于原始阶段的论断。Euplotids are among the best known and most readily recognized ciliates,which have been for a long time regarded as a monophyletic lineage.The order Euplotida contains several well-known taxa,e.g.Euplotes,Diophrys,Uronychia,Aspidisca,Gastrocirrhus,and Discocephalus etc.However,the phylogenetic relationships among them still remain confusing considering their evolutionary process and systematic positions of many groups due to the high diversity of the morphology and lacking molecular data.Phylogenetic trees were constructed in the present work using SS rRNA sequences obtained up-to-date in order to re-evaluate the systematic arrangement. Analyses using different tree construction methods revealed a consistent branching pattern： 1 ） the typical euplotids belong to a paraphyletic group composed of 3 diverged dades （Uronychiidae, Euplotidae-Gertesiidae-Aspidisddae and Gastrocirrhida- e）; 2） both clades formed by Euplotidae-Certesiidae- Aspidisddae and Gastrocirrhidae were firmly supported with high bootstrap; 3） the family Discocephalidae forms a sister group to the large clade containing Euplotidae- Certesiidae-Aspidiscidae and Gastrocirrhidae, though its position remains ambiguous due to low supports; 4 ） Uronychiidae is dearly separated from the most other euplotids, which suggests the family should be positioned in the primordial phase of evolution, and 5 ） within Euplotidae, the present investigation largely disagrees with the species grouping established on morphological grounds.

关 键 词：SS RRNA 游仆目 系统进化 复系 单系 

分 类 号：Q951.2[生物学—动物学]