Genotype and Phylogenetic Diversity of Symbiodinium ITS2 Sequences Within Clade C in Three Typical Coral Species from Luhuitou Fringing Reef of the South China Sea  

作　　者：GONG Sanqiang ZHANG Fengli LI Zhiyong 

机构地区：[1]Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism and School of Life Sciences &Biotechnology, Shanghai Jiao Tong University

出　　处：《Journal of Ocean University of China》2018年第6期1411-1417,共7页中国海洋大学学报（英文版）

基　　金：supported by the Major National Scientific Research Project, China (No. 2013CB956103);the Minhang Leading Talent Project

摘　　要：Dinoflagellates in the genus Symbiodinium, including nine clades(A–I), mainly form mutualistic symbioses with corals. More than 100 Symbiodinium molecular types have been identified by the ITS2-based genotype method within any given clade, and specifically within Symbiodinium clade C. However, the genotype identification method using the ITS2 sequence is likely to lead to high diversity estimates due to the intra-genomic variations in the ITS2 space; thus, further validation is essential for a correct identification. In this study, the molecular diversity of Symbiodinium ITS2 sequences cloned from two stone corals, Acropora sp. SY-01 and Pocillopora sp. SY-05, and one soft coral, Sarcophyton sp. SY-07, living in the northern part of South China Sea(SCS), were analyzed and compared using the ITS2-based genotype identification method, coupled with ITS2-based secondary structural and phylogenetic analyses. As the result, 12 Symbiodinium ITS2 genotypes were identified, while only six and three Symbiodinium ITS2 genotypes were supported by ITS2-based secondary structural and phylogenetic analyses, respectively. In addition, no shared Symbiodinium ITS2 genotypes were observed among the three coral species, suggesting coral species-dependent Symbiodinium genotypes were within clade C. In summary, the present study provides a theoretical basis for validating the molecular diversity of Symbiodinium ITS2 genotypes in corals.Dinoflagellates in the genus Symbiodinium, including nine clades(A–I), mainly form mutualistic symbioses with corals. More than 100 Symbiodinium molecular types have been identified by the ITS2-based genotype method within any given clade, and specifically within Symbiodinium clade C. However, the genotype identification method using the ITS2 sequence is likely to lead to high diversity estimates due to the intra-genomic variations in the ITS2 space; thus, further validation is essential for a correct identification. In this study, the molecular diversity of Symbiodinium ITS2 sequences cloned from two stone corals, Acropora sp. SY-01 and Pocillopora sp. SY-05, and one soft coral, Sarcophyton sp. SY-07, living in the northern part of South China Sea(SCS), were analyzed and compared using the ITS2-based genotype identification method, coupled with ITS2-based secondary structural and phylogenetic analyses. As the result, 12 Symbiodinium ITS2 genotypes were identified, while only six and three Symbiodinium ITS2 genotypes were supported by ITS2-based secondary structural and phylogenetic analyses, respectively. In addition, no shared Symbiodinium ITS2 genotypes were observed among the three coral species, suggesting coral species-dependent Symbiodinium genotypes were within clade C. In summary, the present study provides a theoretical basis for validating the molecular diversity of Symbiodinium ITS2 genotypes in corals.

关 键 词：CLADE C SYMBIODINIUM hard CORAL ITS2 genotypes ITS2 secondary structure PHYLOGENETIC analysis soft CORAL 

分 类 号：P[天文地球]