几种模式生物密码对的偏好模式分析

Analysis of Modes of Codon-pair Biased Usage in Some Mode Species

目的:从进化的角度研究古菌、细菌和真核生物基因组中密码对的使用,得到密码对使用与生物进化的可能的规律。方法:生物统计学。结果:首先,比较了编码序列中密码对出现频数的观测值与理论值之差的分布,发现这种分布基本是随机的;其次,这个分布也表明密码对的使用普遍具有偏好性,且不同物种所偏好的密码对和偏好的程度是不同的;第三,终止密码对的使用也存在偏好性,对于同一个密码子与不同的终止密码组合时,其观察值与理论值的关系依赖于终止密码子的类型。结论:结果表明密码对的使用与基因组进化存在相关性。

Objective: In order to obtain possible rule of codon-pair usage and genome evolution,from the point of view of evolution,to research codon pair usage in archaea,bacteria and eukaryote.Methods: Biostatistics.Results: Firstly,comparative analyses of distribution of the observed and statistically predicted codon pair frequency of occurrence,it is found that the distribution is random basically;secondly,the distribution indicat that most of the codon pairs' usage is bias,and the preference is different from different species;thirdly,most of the sense-stop codon pairs' usage is bias also,when the same sense codon is combined with different stop codon,sense-stop codon pair usage depends on the type of stop codon.Conclusions: The results indicate that the codon-pairs' usage associates with genome evolution.