基于核及叶绿体基因序列探讨中国绿水螅共生单细胞绿藻系统发生地位  

THE SIGNIFICANCE OF PHYLOGENETIC OF UNICELLULAR GREEN ALGAE ENDOSYMBIOTIC IN HYDRA SINENSIS INFERRED FROM NUCLEAR AND CHLOROPLAST GENE SEQUENCES

作　　者：陈磊磊[1] 刘俊红 李全发[1] 董文芳[1] 张行[1] 潘红春[1] 

机构地区：[1]安徽师范大学生命科学学院,重要生物资源保护与利用研究安徽省重点实验室,生物环境与生态安全安徽省高校省级重点实验室,芜湖241000

出　　处：《水生生物学报》2017年第6期1265-1272,共8页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(31370406和31671529)资助~~

摘　　要：研究对中国绿水螅共生绿藻的核18S r RNA基因全长序列及其叶绿体9个基因(atp A、chl B、chl N、pet A、psa B、psb A、psb C、psb D及rbc L)片段序列进行了克隆和测序,并基于18S r RNA基因序列及叶绿体9个基因序列的整合数据分别通过最大似然法(Maximum-likelihood)和贝叶斯分析(Bayesian inference)对中国绿水螅(Hydra sinensis)共生单细胞绿藻的系统发生地位进行了探讨。系统发生表明:(1)中国绿水螅共生绿藻属于共球藻纲(Trebouxiophyceae)小球藻目(Chlorellales),但不属于其中的小球藻属(Chlorella);(2)来源于草履虫、水螅、地衣及银杏的共生绿藻均在共球藻纲支系,而来源于蛙类和蝾螈的共生绿藻属于绿藻纲(Chlorophyceae)支系。无论在共球藻纲支系还是在绿藻纲支系,不同来源的共生藻并没有排他性地聚为单系群而在系统树中与其他自由生活的绿藻混杂排列,来自不同宿主的共生绿藻没有共同起源。In the fields of evolutionary ecology, evolutionary biology and cell biology, symbiosis between Hydra sinensis and single-celled green algae is a special biological phenomenon with high scientific value. Although the biological significance of hydra-algea has been understood, its origin and evolutionary mechanism are still unclear by now. In the hydra-algae symbiosis status, free living algae goes into its host cell during evolution, so the study on the origin of symbiotic algae can help understand the mechanism of hydra-algae symbiosis. In this study, 18 S r RNA gene sequences in nucleolus and nine protein-coding genes（atp A, chl B, chl N, pet A, psa B, psb A, psb C, psb D and rbc L） in chloroplast were cloned and sequenced from the symbiotic green algae in H. sinensis. With the application of Maximum Likelihood（ML） and Bayesian analysis methods, the significance of phylogenetic of the unicellular green algae endosymbiotic in H. sinensis was examined. The results show that the endosymbiotic green alga are belong to Chlorellales, Trebouxiophyceae, instead of Chlorellal; the green alga in paramecium, hydra, lichen and ginkgo are belong to Trebouxiophyceae, whereas others from frog and salamander are in Chlorophyceae. However, these two groups of endosymbiotic alga could live in the same host without forming a monophyletic group. In addition, endosymbiotic alga from different host cells have different origins.

关 键 词：中国绿水螅 共生单细胞绿藻 系统发生 核18S r RNA基因 叶绿体基因 

分 类 号：Q959.131[生物学—动物学] Q949.2