牛亚科动物线粒体基因密码子偏好性及聚类分析

运用多种分析软件对13种牛亚科动物及4种对照动物线粒体的编码蛋白基因进行分析。结果表明,牛亚科动物线粒体基因的有效密码子数(ENC)都小于40.50，显示出明显的密码子偏好性，在碱基组成上偏爱以A结尾的密码子。同义密码子使用度(RSCU)表明，共有13个密码子在编码使用上具有偏好性。在聚类分析中，基于线粒体基因密码子偏好性的聚类结果与基于线粒体基因序列的聚类结果基本一致，说明物种的亲缘关系与密码子使用偏好性有关，线粒体基因密码子偏好性和线粒体基因序列均可以用于物种的分类研究。美洲野牛与牦牛聚为一类，爪哇野牛、普通牛、原始牛和瘤牛聚为一类，支持将牦牛划分为牛亚科中的一个独立属即牦牛属的观点。

Codon Usage Bias and Cluster Analysis of MitochondrialGenes from Bovinae Animals

The softwares were used to analyze mitochondrion coded genes from 13 species in bovinae animals and other control species. Results showed that all ENC values of mitochondrial genes from bovinae animals aree less than 40.50, suggesting that coden usage bias evidently existed. For example, the codons ending with A are frequently used. RSCU showed that 13 codons are preferable in the codons of coding DNA sequences (CDS) of mitochondrial genes. Cluster tree based on the RSCU values of mitochondrial genes from 17 animal species is basically consistent with phylogenetic tree based on mitochondrial gene sequences, which illustrated that genetic relationship is associated with codon usage bias. Both codon usage bias of mitochondrial genes and mitochondrial gene sequences can be used to study the classification of species. In this study, Bison bison and Bos grunniens were gathered together, Bos javanicus, Bos Taurus, Bos primigenius and Bos indicus were gathered together, supporting that Bos grunniens should be divided into a separate genus in bovinae.