Evolutionary relationship and species separation of four morphologically similar stichotrichous ciliates (Protozoa,Ciliophora)  

作　　者：John Clamp Khaled A.S.Al-Rasheid Abdulaziz A.Al-Khedhairy 

机构地区：[1]Department of Biology,North Carolina Central University [2]Zoology Department,King Saud University

出　　处：《Progress in Natural Science:Materials International》2009年第5期581-586,共6页自然科学进展·国际材料（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.30670280,40676076);partially supported by the Center of Excellence in Biodiversity Research;the DNA Research Chair Program,King Saud University

摘　　要：Phylogenetic and taxonomic studies on ciliate protists using molecular approaches have been demonstrated to be very reliable to form strong conclusions and results. In the present work, species separation of some morphologically similar stichotrichous ciliates, two species of Pseudokeronopsis and two species of Apokeronopsis, was reexamined using amplified ribosomal DNA restriction analysis (PCR-RFLP). Five of 10 restriction enzymes revealed species-specific polymorphic patterns, of which four similar stichotrichs could be significantly separated and identified. Among them, EcoR I offered almost no significantly different restriction fragment patterns, but the four species could be separated from one another and identified with Hae Ⅲ. Distinctly different restriction digestion haplotypes and simi-larity indices separated the species, and were used to construct a phylogeny. Phylogenies based on ITS2 nucleotide sequences and ITS2 secondary structures supported the separation of Pseudokeronopsis and Apokeronopsis using RFLP analysis, although three Pseudoker-onopsis carnea populations did not cluster together. In addition, phylogenetic analyses using multiple algorithms confirmed that these two genera formed two distinct groups within the urostylids.Phylogenetic and taxonomic studies on ciliate protists using molecular approaches have been demonstrated to be very reliable to form strong conclusions and results, In the present work, species separation of some morphologically similar stichotrichous ciliates, two species of Pseudokeronopsis and two species of Apokeronopsis, was reexamined using amplified ribosomal DNA restriction analysis （PCR- RFLP）. Five of 10 restriction enzymes revealed species-specific polymorphic patterns, of which four similar stichotrichs could be signif- icantly separated and identified. Among them, EcoR I offered almost no significantly different restriction fragment patterns, but the four species could be separated from one another and identified with Hae Ⅲ. Distinctly different restriction digestion haplotypes and similarity indices separated the species, and were used to construct a phylogeny. Phylogenies based on ITS2 nucleotide sequences and ITS2 secondary structures supported the separation of Pseudokeronopsis and Apokeronopsis using RFLP analysis, although three Pseudoker- onopsis carnea populations did not cluster together. In addition, phylogenetic analyses using multiple algorithms confirmed that these two genera formed two distinct groups within the urostylids.

关 键 词：CILIOPHORA Pseudokeronopsis Apokeronopsis PCR-RFLP ITS2 secondary structures 

分 类 号：Q951[生物学—动物学]