上海四膜虫和两株嗜热四膜虫的rRNA基因ITS-1序列及分子系统关系  

Phylogenetic Relationships among Tetrahymena shanghaienisis and two Strains of Tetrahymena thermophila Inferred from ITS-1 Sequences

作　　者：缪炜[1] 余育和[1] 沈韫芬[1] 

机构地区：[1]中国科学院水生生物研究所,武汉430072

出　　处：《Zoological Research》2001年第4期265-269,共5页动物学研究（英文）

基　　金：国家自然科学基金资助项目 ( 39730 0 70 )

摘　　要：测定并比较了自接型的上海四膜虫 (Tetrahymenashanghaienisis)和两株接合型的嗜热四膜虫(T thermophilaⅡ和T thermophilaⅥ )的ITS - 1序列 ,以多态喇叭虫 (Stentorpolymorphrus)为外来群 ,利用最大简约法和邻接法构建了它们的系统发育树。分析指出 :三者中 ,T shanghaienisis较早地从祖先种中分化出来 ;自接型可能是一种较接合型原始的生殖方式。Phylogenetic relationships among three strains of Tetrahymena (i.e.T.shanghaienisis,T.th- ermophila Ⅱ and T.thermophila Ⅵ) were investigated using sequences of the first internal transcribed spacer region (ITS-1) of ribosomal DNA (rDNA).Amplified rDNA sequences consisted of 221 bases of the flanking 18S and 5.8S regions,and the entire ITS-1 region (169 or 172 bases).There were 5 variable bases among three strains in the 18S region and 16 variable bases in the ITS-1 region.The affiliation of them were assessed using both Neighbor-joining (NJ) and maximum parsimony (MP) analyses.Variations do exist in the phylogenies created by the two methods.However,the basic tree topologies are consistent.In both the NJ and MP analyses,T.shanghaienisis diverge from the ancestor of Tetrahymena earlier than T.thermophila Ⅱ and T.thermophila Ⅵ,which show that the selfer might be primitive.

关 键 词：四膜虫 系统发育 ITS-1 自配型 接合型 分子系统学 

分 类 号：Q959.116[生物学—动物学]