玉米同义密码子使用偏性分析

利用玉米B73全基因组53 764个基因的表达序列数据,使用多重变量分析软件CodonW对影响密码子用法的因素进行分析。结果表明:在59种同义密码子中有27种为玉米最优密码子。同时还指出,最优密码子的使用频率(FOP)与基因的G+C含量(GC),尤其是第3位密码子的G+C百分含量(GC3S)、密码子适应指数(CAI)和密码子偏爱指数(CBI)之间均呈现极显著的正相关(相关系数分别为r=0.780 7、0.822 3、0.731 4和0.986 3),而与有效等位基因数ENc存在显著负相关(相关系数r=-0.681 5)。表明基因GC含量直接影响玉米密码子使用的偏性,同时基因的表达水平越高,对密码子的使用偏向性越强。27个最优密码子的首次确定将对玉米转基因具有重要指导意义。

Analysis of Synonymous Codon Usage Bias in Maize

By using the whole genome sequences of maize inbred B73,twenty-seven optimal codons of maize were identified in 59 synonymous codons and a detailed relative analysis results were obtained by means of a multivariate analysis program-CodonW.The results showed that the frequency of optimal codon（FOP） was present positive correlation with G＋C content of genes（GC,r=0.780 7）,G＋C content at the third position of synonymous codons（GC3S,r=0.822 3）,codon adaptation index（CAI,r=0.731 4）of species and Codon Bias Index（CBI,r=0.9863）.But had negative correlation with effective number of codons（ENc,r=-0.6815）.The results indicated that the codon usage of maize genes influenced mostly by GC content of genes with higher expression showed more significant codon usage bias.Twenty-seven codons identified firstly as optimal codons in B73 may provide some more useful information for maize gene-transformation.