念珠藻类(蓝藻)psb A基因的进化分析  

Evolutionary analysis on psb A gene of Nostoc-like(Cyanobacteria)

作　　者：魏爱丽[1] 杨谢 王捷[1] 巩超彦 王清华 李艳晖[1] Wei Aili;Yang Xie;Wang Jie;Gong Chaoyan;Wang Qinghua;Li Yanhui(Department of Biology,Taiyuan Normal University,Jinzhong 030619,China;Laboratory Management Center,Shanxi University of Chinese Medicine,Jinzhong 030619,China)

机构地区：[1]太原师范学院生物系,山西晋中030619 [2]山西中医药大学实验管理中心,山西晋中030619

出　　处：《河南师范大学学报（自然科学版）》2023年第1期114-120,I0004,I0005,共9页Journal of Henan Normal University(Natural Science Edition)

基　　金：国家自然科学基金(32000167,51709197);山西省“1331工程”服务流域生态治理产业创新学科集群建设项目;山西省基础研究计划面上项目(自由探索类)(202103021224302);山西省高等学校教学改革项目(J2020273).

摘　　要：蓝藻psbA基因家族编码不同形式的D1蛋白,该蛋白是光系统II反应中心的重要组成部分.以39条念珠藻属(Nostoc)及与其同源性较高的psbA基因序列为研究对象,构建最大似然树进行系统发育分析,然后运行PAML4.9软件,使用分支模型、位点模型和分支-位点模型估测氨基酸位点ω值,进一步探讨psbA基因所受到的选择压力.结果表明:(1)系统发育树呈现出内类群中念珠藻分为2个大分支.(2)在分支-位点模型和位点模型下检测出13S,42V,75S,152R和255K为统计学上显著的正选择位点,绝大多数为负选择位点.揭示了念珠藻psbA基因所经历的正选择可能在其适应极端环境中起着重要作用.The psb A gene family in cyanobacteria encodes different forms of the D1 protein which is part of the Photosystem II reaction center.In this study,39 psb A gene sequences with high homology of Nostoc were used to construct a maximum likelihood tree for phylogenetic analysis.Then using PAML4.9 software,the branch model,site model and branch-site models were estimatedωvalues,to explore the selective pressure of the psb A gene.Our results indicate that:(1)the phylogenetic tree showing the inner group could be divided into two large branches of Nostoc.(2)five significant positively selected sites such as 13S,42V,75S,152R and 255K were detected in branch-site models and site model,indicating that most of the sites were under negative selection pressure.Therefore,the results showed that positive selection of psb A might have played an important role in the adaption of Nostoc to the extreme environments.

关 键 词：念珠藻 psb A基因 正向选择 负向选择 

分 类 号：Q941.2[生物学—植物学]