盲蝽科线粒体蛋白编码基因的比较研究  

Comparative study of mitochondrial protein coding genes in Miridae

作　　者：赵婉清 史淦琳 高诗聪 张虎芳 Zhao Wanqing;Shi Ganlin;Gao Shicong;Zhang Hufang(Department of Biology,Xinzhou Teachers University,Xinzhou 034000,China)

机构地区：[1]忻州师范学院生物系,山西忻州034000

出　　处：《山西农业大学学报（自然科学版）》2021年第5期96-103,共8页Journal of Shanxi Agricultural University(Natural Science Edition)

基　　金：山西省高等学校科技创新项目(2019L09841);忻州师范学院院级科研基金资助项目(2018KY04)。

摘　　要：[目的]本研究旨在比较分析盲蝽科线粒体蛋白编码基因的碱基组成、密码子使用情况、基因进化速率等序列特征,并基于13个蛋白编码基因(PCGs)构建盲蝽科的系统发育关系,试图对盲蝽科进行系统全面的比较线粒体基因组学研究。[方法]通过NCBI中的GenBank数据库下载盲蝽科14属代表物种的线粒体基因组,利用Geneious8.0.4抽提13个蛋白编码基因序列。利用MEGA7.0统计碱基组成、起始和终止密码子使用情况、同义密码子使用频率以及序列信息位点。在DNAsp 6.0中计算蛋白编码基因的非同义替换率(Ka)、同义替换率(Ks)和Ka/Ks值,用以评估基因的进化速率。在RAxML⁃7.0.3和MrBayes3.2.2软件中,分别构建基于最大似然法(ML)和贝叶斯法(BI)的系统发育树。利用PartitionFinder选择2种建树方法采用的最优分区和模型。[结果]盲蝽科昆虫线粒体蛋白编码基因的A+T含量为75.5%,atp8的A+T含量最高(83.4%)。起始密码子均为典型的ATN,且ATG和ATT的使用频率较高;终止密码子TAA和T的使用频率较高,TAG较少使用。使用频率最高的同义密码子是UUA(L),且第三位点为A/T的密码子使用频率较高。所有蛋白编码基因的Ka/Ks值都小于1,受到纯化选择的作用。其中,cox1的进化速率最慢,atp8的进化速率最快。ML和BI发育树结果一致,且节点支持率均较高(PP=1.00/BP>73),网蝽科作为外群为一支,盲蝽亚科和叶盲蝽亚科互为姐妹群。在盲蝽亚科中,狭盲蝽族Stenodemini和盲蝽族Mirini互为姐妹群关系。盲蝽族内系统发育关系为:(Apolygus+Lygus)+(Adelphocoris+Creontiades)。[结论]本研究为盲蝽科昆虫的分子进化信息增添了有益的数据,同时也为后续的盲蝽科系统发生关系奠定了科学基础。[Objective]This study aimed to compare and analyze the sequence characteristics of the mitochondrial protein-coding genes of Mirididae,such as the base composition,codon usage,and gene evolution rate.Based on 13 protein-coding genes(PCGs),the phylogenetic relationship of the Mirididae was constructed.The nucleotide composition,codon usage and evolutionary rates were compared and analyzed;A systematic and comprehensive comparative mitochondrial genomic study of Miridae was conducted.[Methods]The mitogenomes of 14 representative species of Miridae were downloaded from GenBank in NCBI,and Geneious8.0.4 was used to extracted 13 PCGs.The nucleotide composition,codon usage and information sites were calculated in MEGA7.0.The non-synonymous substitutions rate(Ka),synonymous substitution rate(Ks)and Ka/Ks of each site of the protein-coding gene were computed in DnaSP 6.0 to evaluate the evolutionary rate of PCGs.The ML and BI phylogenetic trees were constructed in RAxML-7.0.3 and MrBayes3.2.2,respectively.PartitionFinder was used to select the best-fit partitioning schemes and models for phylogenetic analyses.[Results]The A+T content of 13 PCGs was 75.5%,and the content of atp8 was the highest at 83.4%.The start codons were all ATN,and ATG and ATT were used more frequently.The use frequency of stop codons TAA and T was significantly higher than that of TAG.UUA(L)was the codon with the highest frequency,and the synonym codon ended with A/T had a higher frequency.The Ka/Ks ratios for all PCGs were considerably less than 1,indicating the evolution under the purifying selection.The highest evolutionary rate was found in atp8,whereas cox1 had the lowest evolutionary rate.The ML and BI phylogenetic trees were consistent with high node support(PP=1.00/BP>73).For the phylogenetic trees,Tingidae was separated as the outgroup,and Mirinae and Phylinae formed a sister group.The branching relationship within Mirini was as follows:(Apolygus+Lygus)+(Adelphocoris+Creontiades).[Conclusion]This study supplemented molecular evolution infor

关 键 词：盲蝽科 线粒体蛋白编码基因 比较基因组学 系统发育 

分 类 号：S433[农业科学—农业昆虫与害虫防治]