大鳞副泥鳅部分线粒体基因的序列分析研究

Sequence Analysis of Several Mitochondrial Genes in Paramisgurnus dabryanus

通过PCR和DNA测序技术,获得了大鳞副泥鳅(Paramisgurnus dabryanus)线粒体基因组的部分序列,所得4段序列长度共计11552 bp,包括5个蛋白质编码基因(ND1、ND2、ND4、ND4L、ND6和Cytb),14个t RNA基因.本研究获得序列的碱基组成为A 28.9%、C 27.7%、G 15.7%、T 27.7%,可看出(A+T)>(C+G);测出的蛋白编码基因的碱基都有一个明显的现象,就是G的含量很明显的少于其他碱基,而C的含量都比较高,并且(A+T)>(C+G),这样的结果表现出明显的反G偏倚和碱基组成偏好性.将大鳞副泥鳅Cytb序列与Gen Bank其他6种鱼类的Cytb序列进行%对,表明大鳞副泥鳅与洛东江高丽鳅和俄罗斯泥鳅亲缘关系最近.用NJ法构建7种鱼类的进化关系树,结果表明:大鳞副泥鳅与洛东江高丽鳅和俄罗斯泥鳅最先聚类,再与其他鳅科鱼类相聚,最后与鲤科鱼类斑马鱼相聚,结果与传统分类一致.

This research obtained a total of 11556bp fragment of the Paramisgurnus dabryanus mitochondrial gene by using PCR method and analyzed the base composition and codon usage of protein genes in this frag-ment. The sequence contains 5 protein-encoding genes （ND1, ND2, ND4, ND4L and ND6） and one tRNA gene 14tRNA gene. The results showed that the average contents of A,T, C and G bases were 28.9%、27.7%、15.7%and 27.7% respectively, indicating a clear preference for base composition. The codon usage, base composition of ND1, ND2, ND4, ND4L, ND6 and Cytb genes and amino acid composition of the encoded proteins were ana-lyzed in this study, providing a basis for the study of genetic variation on P. dabryanus.