大菱鲆4个引进地理群体遗传多样性的微卫星分析

Analysis of genetic structure among four different stocks of turbot Scophthalmus maximus using microsatellite technique

中文关键词: 大菱鲆  地理群体  微卫星  遗传多样性

英文关键词: Turbot Scophthalmus maximus L.  Geographical stock  Microsatellite DNA  Polymorphic analysis

中文摘要:

      利用12对微卫星分子标记对大菱鲆（Scophthalmus maximus）4个引进地理群体进行遗传多样性分析。结果表明，等位基因数(A)为2~10个，平均等位基因数为4.3，有效等位基因数(Ne)为1.6~6.1，平均有效等位基因数2.7，各位点的杂合度观测值（Ho）0.0000~0.5625，杂合度期望值(He) 0.3823~0.8416。各群体之间无偏倚杂合度期望值由小到大依次为丹麦群体、英国群体、法国群体、挪威群体，运用SPSS软件对无偏倚杂合度期望值进行Kruskal-Wallis检验，其结果（H=4.438,df=3,P=0.218）表明，4个群体的遗传多样性差异不显著。群体间平均遗传分化指数(Fst)为0.1117，各群体之间存在中度遗传分化。用UPGMA 法进行聚类分析，4个群体聚为两类，挪威群体和丹麦群体聚为一类，法国群体和英国群体聚为一类。结合Hardy-Weinberg平衡和遗传偏离指数（d）, 4个群体都不同程度的偏离平衡。4个群体具有一定的遗传分化，较好的遗传多样性，适合作为大规模家系选育的基础群体。

英文摘要:

      Total RNA was extracted from the pituitary gland of half-smooth tongue sole Cynoglossus semilaevis Günther, and the follicle stimulating hormone (FSH) was cloned by using RT-PCR and RACE technology for the first time. The cDNA of FSH is 541bp, and the open reading frame was 393bp encoding peptides of 130 amino acids. This cDNA sequence was submitted to GenBank with Accession No. JQ277933. One N-glycosylation site was found in the deduced amino acid sequence. Multiple amino acid sequences alignments were performed among vertebrates including Osteichthyes, Amphibia, Reptilia, Aves and Mammalia. It showed that half-smooth tongue sole FSH mature peptide was more similar to their orthologs of Pleuronectiformes and Perciformes which was 42%-49% identity than to Cypriniformes and mammalian which was 27%-31% identity. The pairwise distances were computed and phylogenetic trees were constructed using NJ method based on the codon sequences of the chosen species by MEGA 4.0 software. The result indicated that the FSH of half-smooth tongue sole was clustered together with other fish FSH, and the half-smooth tongue sole gene shared high homology with teleost. Real-time PCR analysis showed that FSH mRNA was expressed at the highest level in pituitary. Also strong amplification signals were detected in all other tissues, especially brain and gonad. FSH mRNA of half-smooth tongue sole expressed widely in non-pituitary tissues may indicate that it has more physiological functions.