2种珍稀裂腹鱼类线粒体DNA部分序列片段的比较分析  

Comparative Analysis of mtDNA Gene between Two Rare Schizothoracine Fishes

作　　者：杨天燕[1] 孟玮[1] 张人铭[1] 郭焱[1] 海萨[1] 谢春刚[1] 

机构地区：[1]新疆维吾尔自治区水产科学研究所,乌鲁木齐830000

出　　处：《动物学杂志》2011年第3期47-54,共8页Chinese Journal of Zoology

基　　金：国家自然科学基金项目(No.31060356);新疆维吾尔自治区自然科学基金项目(No.2009211A30)

摘　　要：对扁吻鱼(Aspiorhynchus laticeps)及塔里木裂腹鱼(Schizothorax biddulphi)线粒体COⅠ(624 bp)、Cyt b(712 bp)和D-loop(457 bp)基因片段进行了PCR扩增和序列测定。通过分析比较发现,3个片段A+T含量与其他鱼类相比均较高,G含量偏低这一现象在2个蛋白质编码基因第3位点上显得尤为突出。2种裂腹鱼种内个体间序列变异较小。3个基因片段的核苷酸替代速率依次为D-loop>Cyt b>COⅠ。基于核苷酸最佳替换模型计算2种裂腹鱼在3个基因片段的遗传距离,COⅠ为0.055,Cyt b为0.060,D-loop为0.074。基于Cyt b基因片段序列分析结果表明,扁吻鱼和塔里木裂腹鱼发生遗传分化时间大约在距今3.57百万年左右的上新世,分化时间早于特化等级和高度特化等级裂腹鱼类。塔里木河水系处于青藏高原北部边缘地带,在地理发育上属于青藏高原的一部分,新疆裂腹鱼类的进化一定程度上受到青藏高原隆起这一地质事件的影响。The mtDNA COⅠ（624 bp）,Cyt b（712 bp） and D-loop（457 bp） gene fragments of Aspiorhynchus laticeps and Schizothorax biddulphi were sequenced by PCR respectively and sequence comparisons were made to identify differentiation.The percentage of A＋T content was higher than that of G＋C content in three gene fragments.There was a strong bias against G content,especially in the third codon positions of protein-coding genes（COⅠ and Cyt b）.Sequence analysis indicated that the variation of intra-species was low and the nucleotide substitution rate of three gene fragments arranged from high to low was D-loopCyt bCOⅠ.The estimated divergence time between two Schizothoracine species based on Cyt b gene was about 3.57 MaBP in Pliocene,which was earlier than the specialized grade and high specialized grade species.Because the Tarim River lies in the northern edge of the Qinghai-Tibet Plateau and is geographical development as a part of the Tibetan Plateau,the uplift of Qinghai-Tibet Plateau influences the evolution of Schizothoracine species in Xinjiang to some extent.

关 键 词：扁吻鱼 塔里木裂腹鱼 线粒体DNA 序列分析 遗传差异 

分 类 号：S917.4[农业科学—水产科学]