玉米叶绿体基因密码子使用频率分析

本研究应用软件CodonW,对玉米叶绿体蛋白编码基因的密码子用法进行了初步分析,计算了位于密码子3个位置的GC含量和同义密码子的使用频率,并确定了玉米叶绿体基因组的最优密码子。结果显示玉米叶绿体基因GC含量低,密码子第三位的GC含量最低,偏好使用以A或T碱基结尾的密码子;且确定的25种最优密码子也主要以A或T碱基结尾。分析结果对指导外源基因进行分子改造,提高其在玉米叶绿体中的表达效率及细胞器分子进化研究等具有重要意义。

Analysis of Synonymous Codon Usage in Maize Chloroplast Genome

In this study, the pattern of codon usage of protein encoding genes in maize chloroplast genome was analyzed by software Codon W.The content of G+C at three positions of codons and the frequency of synonymous codon usage were calculated, and the "optimal codons" were determined.The results showed that the content of G+C of genes was low, and the content of G+C at the third position of codons was significantly lower than that of the first and second positions.Genes prefer the codons with A or T at the synonymous position.In addition, 25 codons were affirmed as the "optimal codons", which were mainly ended with A or T.The results provide evidences for these fields, such as molecular modification of exogenous gene to increase the expression efficiency in maize chloroplast, research on molecular evolution of organelle.