革螨亚目线粒体蛋白编码基因的比较研究  

A comparative study of mitochondrial protein-coding genes in the Gamasida

作　　者：杨慧娟 杨志华 陈婷 董文鸽 YANG Hui-juan;YANG Zhi-hua;CHEN Ting;DONG Wen-ge(Institute of Pathogens and Vectors,Dali University,and Yunnan Provincial Key Laboratory for Zoonosis Control,Dali 671000,Yunnan,China)

机构地区：[1]大理大学病原与媒介生物研究所,云南省自然疫源性疾病防控技术重点实验室,云南大理671000

出　　处：《中国病原生物学杂志》2022年第11期1303-1308,1314,共7页Journal of Pathogen Biology

基　　金：国家自然科学基金项目(No.32060143);云南省重大科技计划专项(No.202102AA310055-X)。

摘　　要：目的分析革螨亚目9科20个物种的13个蛋白编码基因序列。方法测定革螨亚目寄螨科寄螨属的粪堆寄螨线粒体基因组全序列,结合GenBank中已有的革螨亚目9科19种革螨的线粒体基因组全序列。用Geneious 11.1.5软件抽提20种革螨的13个蛋白编码基因序列,统计蛋白编码基因的碱基组成、起始和终止密码子使用频率。用MEGA X统计蛋白编码基因的信息位点和密码子使用情况。用软件DnaSP 6.0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,由此分析每个基因的核苷酸进化速率。用13个蛋白编码基因的排列顺序结构图分析9科20种革螨蛋白编码基因的重排现象。用最大似然法(ML)和贝叶斯法(BI)构建9科20种革螨的系统发育树。结果革螨亚目线粒体蛋白编码基因的A+T含量为75.0%,nad6的A+T含量最高(82.1%)。以ATN为起始密码子的使用频率明显高于GTG和TTG;在终止密码子使用中,完整的终止密码子TAA和不完整的终止密码子T的使用频率较高,TAG较少使用。对序列信息和进化速率进行分析,cox1基因的保守位点数最多,进化速率最慢;atp8基因的保守位点数最少,但进化速率最快的是cytb基因;nad5基因的变异位点数和简约信息位点数最多。5个蛋白编码基因的Ka/Ks值<1,受到负选择作用。ML和BI系统发育树结果一致,且节点支持率均较高,分支关系为[(寄螨科+土革螨科)+巨螯螨科+(厉螨科+皮刺螨科+瓦螨科+(鼻刺螨科+蠊螨科)+植绥螨科)]。革螨亚目20种革螨中有5种革螨的蛋白编码基因排列顺序保守,有15种革螨的蛋白编码基因排列顺序不保守,其中植绥螨科物种蛋白编码基因重排程度较高。结论本研究用13个蛋白编码基因序列序列特征探究革螨亚目不同科的系统发生关系,为蜱螨亚纲进化遗传学研究和分子标记选取等提供了参考依据。Objective Analysis of 13 protein-coding gene sequences of 20 species from 9 families of the Gamasida.Methods The complete mitochondrial genome sequence of Parasitus fimetorum of the genus Parasitus of the family Parasitidae in the Gamasida was determined,and combined with the complete mitochondrial genome sequences of 19 species of gamasid mites of 9 families of the Gamasida available in GenBank.The sequences of 13 protein-coding genes of 20 gamasid mites were extracted using Geneious 11.1.5 software,and the base composition,start and stop codon usage frequencies of protein-coding genes were counted.The informative sites and codon usage of protein-coding genes were counted using MEGA X.The DnaSP 6.0 software was used to calculate the non-synonymous substitution rate(Ka),synonymous substitution rate(Ks),and Ka/Ks values of protein-coding genes,from which the nucleotide evolution rate of each gene was analyzed.The rearrangement phenomenon of protein-coding genes of 20 gamasid mites in 9 families was analyzed by using the arrangement order structure plot of 13 protein-coding genes.Limulus polyphemus was selected as the outgroup,and a phylogenetic tree of 20 gamasid mites in 9 families was constructed using MrBayes 3.1.2 and Mega X by Bayesian inference(BI)and maximum likelihood(ML)methods,respectively,in order to study the affinities of the Gamasida.Results The A+T content of the Gamasida mitochondrial protein-encoding genes was 75.0%,showing a strong AT preference.The nad6 gene had the highest A+T content(82.1%)and the cox1 gene had the lowest A+T content(69.3%).The frequency of using ATN as the start codon was significantly higher than that of GTG and TTG,and the nad1 gene used the most abundant start codon species;among the stop codon usage,the complete stop codon TAA and incomplete stop codon T were used more frequently,TAG was used less frequently,and the cox2 gene used the most abundant stop codon species.Analysis of sequence information and evolutionary rate showed that the cox1 gene had the highest number of

关 键 词：革螨亚目 线粒体蛋白编码基因 比较研究 系统发育 

分 类 号：R384.4[医药卫生—医学寄生虫学]