| 摘要: |
| 【目的】获得三倍体虹鳟线粒体基因组（mtDNA）全序列，揭示其序列的主要结构特征，探究三倍体虹鳟系统发育相关信息，丰富鲑科鱼类mtDNA数据库，为三倍体虹鳟进化和系统发育研究提供参考。【方法】选取健康状况良好且规格相似的三倍体虹鳟3条，采集其背脊上部肌肉组织，提取基因组DNA，检测DNA质量后通过Illumina测序技术对三倍体虹鳟mtDNA进行测序、组装和注释，并进行生物信息学分析；基于已报道的27种鲑科鱼类的mtDNA，运用邻接法（neighbour joining，NJ）构建鲑科鱼类系统发育树。【结果】三倍体虹鳟mtDNA全长为16 655 bp；A+T含量较高（54.06%），G+C含量较低（45.94%）,其碱基组成有明显的A/T偏向性。三倍体虹鳟mtDNA包括13个蛋白编码基因、2个rRNA基因、22个tRNA基因和1个非编码控制区（D-loop区）。13个蛋白编码基因中，除cox1的起始密码子为GTG外，其他12个基因的起始密码子均为ATG，终止密码子均为TNN；2个rRNA基因总长度为2 606 bp，22个tRNA基因中除trnS1外，其余21个基因均能形成典型的三叶草结构；D-loop区在环状的DNA分子中位于trnF和trnP之间。系统发育树结果显示，28个物种明显分为2个大的支系，鲑亚科的麻哈鱼属、副哲罗鱼属、细鳞鲑属、哲罗鱼属、红点鲑属、鳟属的鱼种聚为一支，其中三倍体虹鳟和虹鳟最先聚为一支，表明其亲缘关系最近；茴鱼亚科茴鱼属和白鲑亚科的白鲑属、柱白鲑属鱼种聚为另一支。【结论】获得了三倍体虹鳟mtDNA，三倍体虹鳟与虹鳟亲缘关系最近。 |
| 关键词: 三倍体虹鳟 线粒体基因组 系统进化 |
| DOI： |
| 分类号: |
| 基金项目:青海省重大科技专项（2019-NK-A2） |
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| Mitochondrial genome structure and phylogenetic analysis of triploid rainbow trout |
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LI Zhaonan,LI Changzhong,KONG Lingcai,et al
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| Abstract: |
| 【Objective】This study obtained the complete mitochondrial genome sequence (mtDNA) of triploid rainbow trout,revealed key sequence structural features,explored phylogenetic information of triploid rainbow trout and enriched the mtDNA database of salmonid fishes to provide references for evolutionary and phylogenetic studies of triply distributed rainbow trout.【Method】Three healthy and similar-sized triploid rainbow trout were selected,and their upper dorsal spinal muscular tissue was harvested for genomic DNA extraction.The triploid rainbow trout mtDNA was sequenced,assembled and annotated by Illumina sequencing technology after quality control of DNA,followed by bioinformatic analysis.Neighbour-Joining (NJ) was used to build a phylogenetic salmonid fish tree.【Result】The mtDNA of triploid rainbow trout was 16 655 bp in length with high A+T (54.06%) and low G+C (45.94%).Its base composition had a clear A/T bias.The triploid rainbow trout mtDNA was composed of 13 protein-coding genes,2 rRNA genes,22 tRNA genes and 1 noncoding control region (D-loop region).Among the 13 protein-coding genes,12 had an ATG start codon and a TNN stop codon,except for cox1,which had a GTG start one.The total length of the 2 rRNA genes was 2 606 bp and 21 out of 22 tRNA genes except trnS1 were able to form a typical trilobal structure.The D-loop region was located between trnF and trnP in the circular DNA molecule.The results of the phylogenetic tree showed that the 28 species were clearly divided into two large clades,with species of Oncorhynchus,Parahucho,Brachymystax,Phyllostomus,Hucho,Salvelinus and Salmo in the Salmonidae clustered into one clade.The triploid rainbow trout and Oncorhynchus mykiss firstly clustered into one clade,indicating their closest kinship.The genus species in the Thymallinae Thymallus and Coregonus and Prosopium species in the Coregoninae clustered into another clade.【Conclusion】mtDNA of triploid rainbow trout was obtained,and triploid rainbow trout and Oncorhynchus mykiss were most closely related. |
| Key words: triploid rainbow trout mitochondrial genome phylogenetic evolution |
