5种鳎科鱼类核糖体ITS1序列比较  

Comparative analysis of the first internal transcribed spacer of ribosomal DNA in five Soleidae species

作　　者：龚理[1,2,3] 时伟[2] 杨敏[2,3] 司李真 孔晓瑜[2] GONG Li SHI Wei YANG Min SI Lizhen KONG Xiaoyu(Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, China Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]广西科学院广西红树林研究中心,广西红树林保护与利用重点实验室,广西北海536000 [2]中国科学院南海海洋研究所,热带海洋生物资源与生态重点实验室,广东广州510301 [3]中国科学院大学,北京100049

出　　处：《水产学报》2017年第3期321-329,共9页Journal of Fisheries of China

基　　金：国家自然科学基金(31272273);广西红树林保护与利用重点实验室开放基金(GKLMC-201502)~~

摘　　要：核糖体基因在很长一段时间内被认为严格遵循协同进化方式,但是在很多种类中都发现了明显的序列多态性,表明其是非协同进化。为了检测鳎科鱼类核糖体内转录间隔区1(ITS1)序列是否存在多态性,并探究其能否作为种类鉴定的分子标记,本研究克隆获得了5种鳎科鱼类共118条ITS1全序列。结果显示,眼斑豹鳎具有两种差异显著的片段类型,表明其在基因组中遵循非协同进化方式;而在其余4种鳎科鱼类中均没有发现序列多态性,表明其为协同进化。序列分析显示ITS1具有明显的种间长度异质性,最短的序列出现在蛾眉条鳎(412 bp),最长的为眼斑豹鳎(585 bp)。碱基分析显示ITS1序列在5种鳎科鱼类中都呈现出相同的趋势:C>G>A>T,且GC含量为69.5%,远高于AT含量。聚类分析显示除眼斑豹鳎外,所有鳎类均单独聚为一支,种类区分度非常明显,表明ITS1序列能够作为种类鉴定的分子标记。但是眼斑豹鳎的一个克隆和东方箬鳎聚为一支,这种序列多态性对种类鉴定产生了干扰,因此用具有多态的ITS1序列作为分子标记时一定要有足够的克隆数量,避免因数据不充分而得到不正确的结论。For a long time,the ribosomal RNA gene was thought to conform to the paradigm of strict concerted evolution pattern.In fact,an increasing number of intraindividual and intraspecies variations have been discovered,indicating non-concerted evolution.In order to explore the polymorphism of the first internal transcribed spacer（ITS1） in the species of Soleidae in Pleuronectiformes and whether it is suitable as a marker for species identification,a total of 118 ITS1 sequences were determined from five soles.The results showed that two distinct types were found in Pardachirus pavoninus genome,suggesting a non-concerted evolution pattern,while concerted evolution was confirmed in other four soles because of absence of intraindividual polymorphism.Sequence analysis demonstrated that ITS1 had significant length heterogeneity,ranging from 412 bp in Zebrias quagga to 585 bp in P.pavoninus.The base content of sequences in all five soles was in the same trend with C〉G〉A〉T and GC content（69.5%） was far higher than AT content.Except for one sequence of P.pavoninus,each of five soles clustered into one clade,respectively,suggesting ITS1 sequence was suitable for species identification in the present study.It is worth noting that the sequence of P.pavoninus clustered with Brachiru orientalis,suggesting that ITS1 sequence polymorphism interfered species identification,as a result,it is essential to obtain enough clones before using ITS1 sequence as the molecular marker for species identification in order to avoid incorrect conclusions.

关 键 词：鳎科 内转录间隔区 种类鉴定 分子标记 假基因 非协同进化 聚类分析 

分 类 号：Q522[生物学—生物化学] S917.4[农业科学—水产科学]