肠舌状绦虫线粒体基因组特征及系统发育分析  

Characteristics and Phylogenetic Analysis of Mitochondrial Genome in the Ligula intestinalis

作　　者：陈秀琴 邱阳元 吕庆博 黄梅清[1] CHEN Xiuqin;QIU Yangyuan;L Qingbo;HUANG Meiqing(Institute of Animal Husbandry and Veterinary Medicine,Fujian Academy of Agricultural Scienc/Fujian Animal Diseases Control Technology Development Center,Fuzhou,Fujian 350013,China;Key Laboratory of Zoonosis Research,Ministry of Education/Institute of Zoonosis,College of Veterinary Medicine,Jilin University,Changchun 130062,China)

机构地区：[1]福建省农业科学院畜牧兽医研究所/福建省畜禽疫病防治工程技术研究中心,福州350013 [2]吉林大学动物医学学院人兽共患病研究所人兽共患病研究教育部重点实验室,长春130062

出　　处：《畜牧兽医学报》2024年第12期5725-5737,共13页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：福建省属公益类科研院所项目(2023R1024002);福建省农业科学院自由探索科技创新项目(ZYTS2023017)。

摘　　要：本研究旨在获得肠舌状绦虫线粒体基因组全序列,了解其序列的结构特征,探究肠舌状绦虫系统发育相关信息。从麦穗鱼中获得肠舌状绦虫,提取基因组DNA,通过Illumina测序技术对肠舌状绦虫的线粒体全基因组进行测序、组装和注释,并进行生物信息学分析;从GenBank数据库中下载8个科34种绦虫的线粒体基因组序列,运用最大似然法和贝叶斯法构建系统发育树。结果显示,肠舌状绦虫线粒体基因组全长为13655 bp,A+T含量为67.6%,其碱基组成具有明显的AT偏向性。肠舌状绦虫线粒体基因组包括12个蛋白编码基因(protein-coding genes,PCGs)、22个tRNA基因、2个rRNA基因和2个非编码控制区。在12个PCGs中,除cox3基因使用TTG作为起始密码子外,其余11个PCGs均使用ATG作为起始密码子;终止密码子方面,5个PCGs使用TAA,5个PCGs使用TAG,而cox3基因和nad3基因均没有终止密码子。PCGs使用密码子频率最高的是UUA,最低的是CGA。22个tRNA基因总长为1272 bp,大多数tRNA能形成典型的三叶草结构,但是trnS1和trnR由于缺少二氢尿嘧啶臂无法形成典型的三叶草结构。nad2、nad 6和nad 4基因更适合作为肠舌状绦虫的分子标记。系统发育树结果表明,肠舌状绦虫与双线绦虫亲缘关系最近,并与双槽头属绦虫(Dibothriocephalus)形成姐妹群。本研究获得了肠舌状绦虫的线粒体全基因组,为研究肠舌状绦虫的分类学和系统学提供参考。This experiment was conducted to obtain the complete mitochondrial genome sequence of Ligula intestinalis,revealed the sequence’s structural features,and explored the phylogenetic information of L.intestinalis.Several L.intestinalis were obtained from Pseudorasbora parva and genomic DNA was extracted.The complete mitochondrial genome of L.intestinalis was sequenced,assembled,and annotated using Illumina sequencing technology after quality control of the DNA,followed by bioinformatic analysis.Maximum likelihood(ML)and bayesian inference(BI)analysis were used to construct the phylogenetic tree.The results showed that the complete mitochondrial genome of L.intestinalis was 13655 bp in length,and its A+T content was 67.6%,exhibiting a clear AT bias.The complete mitochondrial genome was composed of 12 protein-coding genes(PCGs),22 tRNA genes,two rRNA genes and two NCRs(non-coding regions).Among the 12 PCGs,11 used ATG as the start codon,except for cox3,which had a TTG initial one.Among the termination codons,five out of twelve were identified as TAA,five as TAG,while neither the cox3 nor nad3 genes had termination codons.The total length of the 22 tRNA genes was 1272 bp.Most tRNAs have a conventional cloverleaf structure,but trnS1 and trnR lack dihydrouridine arms of tRNA.The nad2,nad6 and nad4 genes are more suitable as molecular markers for L.intestinalis.The results of the phylogenetic tree showed that Ligula and Digramma were most closely related to each other,forming a sister group with Dibothriocephalus.The complete mitochondrial genome of L.intestinalis was obtained.This study will provide a reference for the study of the taxonomy and systematics of L.intestinalis.

关 键 词：肠舌状绦虫 线粒体基因组 结构特征 系统发育 

分 类 号：S852.734[农业科学—基础兽医学]