墨脱新光唇鱼线粒体全基因组测序与系统发育分析  

Mitochondrial Genome Structure and Phylogenetic Analysis of Neolissochilus hexagonolepis

作　　者：杨培灿 韩学凯 张驰 YANG Peican;HAN Xuekai;ZHANG Chi(Institute of Fisheries Science,Tibet Academy of Agricultural and Animal Husbandry Sciences,Lhasa,850002;College of Marine and Environmental Sciences,Tianjin University of Science and Technology,Tianjin,300457)

机构地区：[1]西藏自治区农牧科学院水产科学研究所,拉萨850002 [2]天津科技大学海洋与环境学院,天津300457

出　　处：《基因组学与应用生物学》2025年第2期144-156,共13页Genomics and Applied Biology

基　　金：西南地区重点水域渔业资源与环境调查专项(CJW2023034);西藏自治区重点科技计划项目(XZ202301ZY0012N);国家重点研发计划项目(SQ2024YFD120002203)共同资助。

摘　　要：墨脱新光唇鱼(Neolissochilus hexagonolepis)属于雅鲁藏布江下游特有土著鱼类,具备良好的产业化开发前景。本研究测定了墨脱新光唇鱼的线粒体基因组全序列,并对其进行系统发育分析。结果表明:墨脱新光唇鱼线粒体基因组的大小为16562 bp,包含13个蛋白编码基因(protein-coding genes,PCGs)、22个转运RNA(transfer RNAs,tRNAs)基因、2个核糖体RNA(ribosomal RNAs,rRNAs)基因和1个控制区(displacement-loopregion,D-loop);碱基组成表现出明显的AT偏好性;13个PCGs仅nad6基因位于L链上,含量最高的氨基酸是亮氨酸(16.58%);除tRNASer(GCT)缺少DHU臂以外,其他21个tRNA基因都能形成典型的三叶草结构;D-loop区识别出3个结构域:终止序列区(termination associated sequence,TAS)、中央保守区(central conserved domain,CD)和保守序列区(conserved sequence block,CSB);基于线粒体全基因组序列和线粒体细胞色素c氧化酶第1亚基(cytochrome c oxidase subunit 1,cox1)基因序列构建系统发育树,验证了墨脱新光唇鱼的系统发育地位及其分类符合新光唇鱼属(Neolissochilus)的特征。研究结果发现,雅鲁藏布江下游的墨脱新光唇鱼与印度的墨脱新光唇鱼遗传距离大于2.00%,分子水平差异较大,对两个种群是否为同一物种提出疑问。该研究为雅鲁藏布江下游流域墨脱新光唇鱼的分类鉴定、系统进化及资源保护等提供了参考依据。Neolissochilus hexagonolepis belongs to the endemic indigenous fish species in the lower reaches of the Yarlung Zangbo River and has promising prospects for industrial development.This study determined the complete mitochondrial genome sequence of N.hexagonolepis and conducted a systematic phylogenetic analysis.The results indicated that the mitochondrial genome of N.hexagonolepis was 16562 bp in length,comprising 13 protein-coding genes(PCGs),22 transfer RNAs(tRNAs)genes,2 ribosomal RNAs(rRNAs)genes,and 1 displacement-loop region(D-loop).The base composition showed a significant AT bias.Thirteen PCGs were present exclusively on the L-strand,with the nad6 gene being the sole occupant.Among these,leucine constituted the highest proportion of amino acids at 16.58%.All 22 tRNA genes,except tRNA~(Ser(GCT))which lacked the DHU arm,were capable of forming the typical cloverleaf structure.The D-loop region contained three structural domains:termination-associated sequences(TAS),central conserved domain(CD),and conserved sequence block(CSB).A phylogenetic tree was constructed based on the complete mitochondrial genome sequence and the mitochondrial cytochrome c oxidase subunit 1(cox1),which supported the systematic position of N.hexagonolepis and confirmed its classification within the Neolissochilus genus.The research findings revealed a genetic distance greater than 2.00%between N.hexagonolepis populations in the lower Yarlung Tsangpo River and those in India,suggesting significant molecular-level differences and raising questions about whether these populations belonged to the same species.This study provided a reference for the classification,systematic evolution,and conservation of N.hexagonolepis in the lower Yarlung Tsangpo River basin.

关 键 词：墨脱新光唇鱼 线粒体基因组 序列分析 系统进化 

分 类 号：S917.4[农业科学—水产科学]