斜带髭鲷线粒体DNA 控制区序列的结构分析

采用PCR技术获得我国南海斜带髭鲷(Hapalogenys nitens)养殖及野生群体共50尾样品的mtDNA控制区全序列,长度范围788 ～790 bp;测得序列与GenBank下载的其他鲈形目鱼类D-loop全序列利用CLUSTAL X进行排序后,对控制区结构进行分析.识别了其终止结合序列区、中央保守区和保守序列区,指出了终止相关序列的主体是TACAT与其反向互补序列ATGTA以及一系列保守序列(CSB-F、CSB-E、CSB-D和CSB-1、CSB-2、CSB-3),并给出了其一般形式；此外,基于斜带髭鲷D-Loop全长序列,利用贝叶斯法构建了分子系统进化树.结果显示,斜带髭鲷养殖群体与野生群体部分样品各自紧密聚成一小支,而在整棵进化树上,养殖样品与野生样品相互交错聚集在一起,可见本研究海区斜带髭鲷养殖群体与野生群体之间的遗传差异分化不显著.

Structure of Mitochondrial Control Region Sequence of Hapalogenys nitens

Complete sequences of mitochondrial DNA (mtDNA) control region from total 50 samples of cultured and wild Hapalogenys nitens of South China Sea were amplified by Polymerase Chain Reaction (PCR), the length ranged from 788-790bp. All sequences were aligned by Clustal X with other Perciformes species from GenBank and the structures of the control region were analyzed. Three domains of the control region, the termination associated sequence domain (TAS), the central conserved domain (CD) and the conserved sequence block domain (CSB) were identified from the aligned sequences. A termination associated sequence (TACAT) and its reverse complementary sequence (ATGTA) were found in the TAS domain. Three conserved blocks (CSB-F, CSB-E, and CSB-D) in the CD domain and three conserved sequence blocks (CSB-1, CSB-2, CSB-3) in the CSB domain were also identified in the control region of H. nitens. In addition, molecular phylogenetic tree based on complete D-loop sequences was constructed by Bayesian method. The result showed that, some samples from the cultured and wild H. nitens were grouped in small branches, respectively. But all samples between cultured and wild H. nitens were clustered together in the whole tree. In this study, the genetic difference between cultured and wild H. nitens captured in this sea was not so significant.