Monophyly or polyphyly? Possible conflict between morphological and molecular interpretations of the wellknown genus Zoothamnium(Ciliophora,Peritrichia)

作     者：李丽芳 马洪钢 AL-RASHEID Khaled A.S. 

作者机构：Marine CollegeShandong University Institute of Evolution & Marine BiodiversityOcean University of China Zoology DepartmentKing Saud University 

出 版 物：《Chinese Journal of Oceanology and Limnology》 (中国海洋湖沼学报（英文版）)

年 卷 期：2015年第33卷第2期

页      面：490-499页

核心收录：

学科分类：0908[农学-水产] 09[农学] 

基　　金：Supported by the National Natural Science Foundation of China(Nos.31071898,31111120437) the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China the Key Laboratory of Mariculture(KLM),Ministry of Education,Ocean University of China,the Research Group Project(No.RGP-VPP-083) the King Saud University Deanship of Scientific Research 

主　　题：peritrichous ciliates Zoothamnium phylogenetic analyses monophyly polyphyly 

摘      要：In this paper, we explore possible conflict between morphological and molecular interpretations of phylogenetic relationships within the well-known peritrichous genus Zoothamnium. On the basis of morphological evidence, for a long time this genus has been believed to be a well-defined monophyletic taxon. Nonetheless, Zoothamnium exhibits higher genetic diversity than the gross morphology of its species. Here, we used all available genetic information for the small subunit of ribosomal RNA （SSU rRNA） and internal transcribed spacer region （ITS1-5.8S-ITS2） for this genus to reconstruct phylogenies for four datasets （SSU rRNA, ITS1, ITS2, and ITS1-5.8S-ITS2） and a combined dataset （SSU rRNA＋ITSI-5.8S- ITS2） using different phylogenetic methods and with consideration of the secondary structure of the genes. Confidence in phylogenetic tree selection was assessed with the approximately unbiased test. The molecular results showed both that Zoothamnium is more likely to be polyphyletic, and morphologically similar genera Zoothamnopsis and Myoschiston were always nested among Zoothamnium species. Accordingly, as with some other groups of ciliates, to understand more fully the correct phylogeny of Zoothamnium there remains a need for additional data from both morphological and molecular studies, covering additional Zoothamnium spp. and members of closely related genera （e.g. Zoothamnopsis, Myoschiston, and Epistylis）.