松江鲈鱼Cytb基因序列分析及种质鉴定

The Sequence Analysis of Mitochondrial Cytochrome b Gene and Identification of Trachidermus fasciatus Heckel

采用PCR方法扩增四尾松江鲈鱼线粒体细胞色素b(mitochondrial cytochrome b,Cytb)基因序列,全序列长度为1 141 bp,并建立了松江鲈鱼的实时定量PCR检测方法对该物种进行种质鉴定。分析Cytb基因序列基本特征显示,Cytb基因在第3位密码子表现出明显的反G偏倚,显示出脊椎动物Cytb基因的共同特性。第2位密码子嘧啶的含量远高于嘌呤的含量,有5个位点发生转换,0个位点发生颠换。选取杜父鱼科(Cottidae)的10种鱼类,与松江鲈鱼进行序列分析,构建发育系统树并分析遗传距离,与鲈鱼的亲缘关系最远。以松江鲈鱼Cytb基因序列为靶基因,利用PRIMER EXPRESS2.0软件设计引物和Taqman探针,建立检测松江鲈鱼的定量PCR方法,特异性强,灵敏度高,检测限为3.20×102拷贝/反应。

The mitochondrial cytochrome b gene （ Cytb ） of 4 Trachidermus fasciatus Heckel was amplified by PCR, cloned and sequenced. The complete sequence of Cytb was 1 141 bp, the third codon exhibited anti-G bias, which is a common characteristics of vertebrates. Pyrimidines are over-represented compared with purines at the second codon. There were five transitional positions and no transversion. The sequence comparison between 10 species of Cottidae and Trachidermusfasciatus Heckel has been carried out for phylogentic trees and analysis of sequence distance. It was showed that Trachidermusfasciatus Heckel was clustered to a single clade. There is relatively farther relationship between Laterolabraxjaponicus and Trachidermusfasciatus Heckel. The quantitative PCR amplification with good sensitivity and speciality has been established for detection Cytb gene of Trachidermusfasciatus Heckel. The detecting limit of this method is 3.20 ×10^2 copies/reaction.