基于密码对使用的基因组进化

Analysis of genome similarity based on codon-pair usage

以密码对使用偏好性和密码对中二核苷酸频率分别构建了系统发育树。发现用40种模式生物编码序列中密码对的二核苷酸频率构建的系统发育树,明显将生物按进化分成细菌,古菌,真核生物;用密码对使用偏好性指标构建的系统发育树与基于密码对中二核苷酸频率的系统发育树基本一致。结果表明密码对中二核苷酸组分是密码对偏好的决定因素之一。

The phylogenetic trees are constructed using the codon-pair usage bias and the dinucleotide frequencies within codon-pairs.A phylogenetic tree constructed using the dinucleotides frequencies within codon-pairs in 40 mode organisms shows that the organisms are apparently divided into three evolutionary groups,Bacteria,Archaea,and Eukaryota.Another phylogenetic tree constructed using the index reflecting codon-pair usage bias is consistent with the phylogenetic tree constructed based on the dinucleotides frequencies within codon-pairs.Our results indicate that the component of dinucleotides within codon-pairs is one of the determinants of codon-pair bias.