基于胡鲇科和鲇科ESTs序列初步筛选兰州鲇EST-SSR分子标记  

preliminary screening of Silurus lanzhouensis EST-SSR markers based on Clariidae and Siluridea ESTs

作　　者：魏大为[1,2,3] 连总强[1,2,3] 吴旭东[1,2,3] 王发新 李力 俞兆曦 杨忠礼[1,2] 

机构地区：[1]甘肃农业大学动物科学技术学院,兰州730070 [2]宁夏回族自治区水产研究所,银川750001 [3]宁夏渔业工程技术研究中心,银川750001

出　　处：《淡水渔业》2015年第5期19-23,共5页Freshwater Fisheries

基　　金：国家自然科学基金项目(31360633);宁夏对外科技合作项目

摘　　要：利用SSRHunter软件对现已公布的鲇形目（Siluriformes）中胡鲇科（Clariidae）和鲇科（Siluridea）共2002条EST（Expressed Sequence Tag）序列筛选兰州鲇（Silurus lanzhouensis）微卫星标记,并分析其序列丰度和分布特征。结果共发现209个微卫星序列,占整个ESTs数据库的10.44%;其中三碱基重复序列数量最多,占ESTs数据库中发现微卫星序列总数的35.62%;二、四、五、六碱基重复序列分别占微卫星序列总数的28.31%、25.57%、7.76%、2.74%。根据侧翼序列,设计125对引物,随机选取58对进行扩增鉴定及多态性筛选。结果显示29对引物能稳定扩增,16对引物具有多态性,每个位点等位基因数2-7个（平均3.75）,观测杂合度（Ho）0.133 2-0.732 2（平均0.405 1）,期望杂合度（He）0.198 2-0.848 3（平均0.560 2）,多态信息含量（PIC）0.124 1-0.794 5（平均0.506 5）。研究表明,借用已有鲇形目鱼类ESTs数据库筛选到的兰州鲇微卫星标记质量较好,可为兰州鲇种质资源保护、微卫星连锁图谱构建、经济性状的QTL定位及分子标记辅助育种奠定基础。Microsatellites markers of Silurus lanzhouensis were screened from 2 002 published ESTs of Clariidae and Siluridea, and the abundance and distribution of the sequence were analyzed by SSRHunter software. The results showed that 209 SSRs were mined from all ESTs with a frequency of 10. 94%. Trinucleotide repeats EST-SSRs were dominant, accounting for 35.62% in all SSRs, dinucleotide, tetranucleotide, pentanucleotide and hexanucleode accounting for 28. 31% , 25.57%, 7.76%, 2. 74% respectively. According to unique sequences flanking each motif, we designed 125 pairs of SSR-primers and synthesized 58 pairs of them, 15 polymorphic microsatellite markers were screened out. Using 15 pairs of these microsatellite markers, we analyzed genetic structures of one S. lanzhouensis population ; the alleles were ranged from 2 to 7 （ average 3.75 ）. The ranges of observed and expected heterozygosity were 0. 133 2 to 0. 732 2 （ average 0. 405 1 ） and 0. 198 2 to 0. 848 3 （average 0. 560 2 ） , respectively, and the polymorphic information content were ranged from 0. 124 1 to 0. 794 5 （average 0. 506 5）. The results indicate that isolate S. lanzhouensis EST-SSR markers screening from Clariidae and Siluridea ESTs sequences was a good method for enhancing the efficiency of isolating microsatellite DNAs. These microsatellite markers would offer solid foundation for S. lanzhouensis resources conservation and microsatellite genetic linkage mapping construction. Besides, they would also be helpful for marker-assisted selection and quantitative trait loci location analysis of S. lanzhouensis.

关 键 词：兰州鲇(Silurus lanzhouensis) 微卫星标记 表达序列标签(EST) 特征分析 

分 类 号：S917.4[农业科学—水产科学]