横纹蓟马(缨翅目:纹蓟马科)线粒体基因组测序与分析

Sequencing and analysis of the mitochondrial genome of Aeolothrips fasciatus (Thysanoptera:Aeolothripidae)

  • 摘要: 目的 明确横纹蓟马(Aeolothrips fasciatus)的线粒体基因组结构特征,并依据线粒体基因组序列探究其系统发育关系,为进一步明确纹蓟马科各类群的亲缘关系和分类地位提供分子依据。方法 利用第二代测序技术(NGS)的Illumina NovaSeq 6000平台对横纹蓟马线粒体基因组进行测序,并对基因组序列进行注释和分析;基于50种缨翅目昆虫线粒体基因组中的13个蛋白质编码基因(PCGs)串联22个转运RNA(tRNA)基因共同构建数据集矩阵,以桃粉大尾蚜(Hyalopterus arundiniformis)作为外群,运用最大似然法(ML)和贝叶斯法(BI)构建系统发育树,分析横纹蓟马与其他种类蓟马之间的系统发育关系。结果 横纹蓟马线粒体基因组总长度为19167 bp,其中包括13个PCGs、22个tRNA基因和2个核糖体RNA(rRNA)基因,共计37个基因,并含有2个非编码的控制区(CR)。横纹蓟马线粒体基因组的编码区中有10处基因重叠区和21处基因间隔区。横纹蓟马线粒体基因组具有缨翅目昆虫典型线粒体基因的基因组成和排列顺序,AT含量为71.5%,表现为明显的AT偏斜。横纹蓟马线粒体的13个PCGs中,除cox3基因采用GTG作为起始密码子、nad3基因采用TTG作为起始密码子外,其余11个PCGs均以ATN作为起始密码子;对于终止密码子,除atp6nad1基因采用不完整的T作为结尾、nad2基因以TAG作为终止密码子外,其他10个PCGs均采用TAA作为终止密码子。除trnH基因缺少TφC环、trnS1基因缺少DHC臂外,其余20个tRNA基因均呈现出完整的三叶草结构。横纹蓟马的基因重排发生剧烈,至少有26个基因发生易位。系统发育分析结果显示,横纹蓟马与印度纹蓟马(Aeolothrips indicus)聚在同一分支上。结论 成功获得横纹蓟马线粒体基因组完整序列,该虫的线粒体基因组结构与纹蓟马科昆虫线粒体基因组结构一致;系统发育分析表明横纹蓟马与印度纹蓟马的亲缘关系较近;纹蓟马科可形成一个稳定的单系。

     

    Abstract: Objective This study aimed to characterize the mitochondrial genome structure of Aeolothrips fasciatus, and investigate its phylogenetic relationships based on its mitochondrial genome sequences, so as to provide molecular evidence for clarification of the phylogenetic relationships and taxonomic status of various groups within Aeolothripidae.Method The mitochondrial genome of Aeolothrips fasciatus was sequenced using next-generation sequencing (NGS) of the Illumina NovaSeq 6000 platform. The genome sequences were annotated and analyzed. A dataset matrix was established based on the 13 protein-coding genes (PCGs) and 22 transfer RNA (tRNA) genes from the mitochondrial genome of 50 species of Thysanoptera. With Hyalopterus arundiniformis as the outgroup, the phylogenetic tree was established employing both maximum likelihood (ML) and Bayesian inference (BI) methods to analyze the polygenic relationship between Aeolothrips fasciatus and other thrip species.Result The complete mitochondrial genome of Aeolothrips fasciatus was 19167 bp in length, comprising of 37 genes—13 PCGs, 22 tRNA genes, 2 ribosomal RNA (rRNA) genes—along with 2 non-coding control regions (CRs). Within the coding regions of Aeolothrips fasciatus, 10 gene overlaps and 21 intergenic spacers were identified. The genome of Aeolothrips fasciatus exhibited typical mitochondrial genome compositions and arrangements of Thysanoptera species, with its AT content of 71.5%, indicating a pronounced AT skew. In the 13 PCGs of mitochondria in Aeolothrips fasciatus, gene cox3 took GTG as the start codon, gene nad3 took TTG as the start codon, the rest 11 PCGs took ATN as the start codon. For the stop condons, genes atp6 and nad1 had their stop codons ended with T, the gene nad2 took TAG as its stop codon, the rest 10 PCGs took TAA as their stop condons. The gene trnH lacked the TφC ring, and trnS1 lacked the DHC arm, but the other 20 tRNA genes exhibited a complete clover-shape structure. Extensive gene rearrangements were observed, with at least 26 genes showed translocation. Phylogenetic analysis showed that Aeolothrips fasciatus was cluster with Aeolothrips indicus in the same branch.Conclusion The complete mitochondrial genome sequence of Aeolothrips fasciatus is obtained. The mitochondrial genome structure of Aeolothrips fasciatus is consistent with mitochondrial genomes of Aeolothripidae insects. Phylogenetic analysis shows that Aeolothrips fasciatus shares a near relationship with Aeolothrips indicus. Aeolothripidae itself could form a stable monophyly.

     

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