烟草叶绿体密码子的偏好性及聚类分析

综合运用多种软件对3种烟草属植物以及其他对照植物的6个叶绿体蛋白编码基因进行了分析.结果表明,普通烟草在密码子使用特性上与林生烟草最为接近,在所分析的59个密码子中,有39个密码子的RSCU( Relative Synonymous Codon Usage)值完全一样;8种参与分析的植物中共出现了30个具有偏好使用的密码子,其中7种双子叶植物在碱基组成上偏爱以C结尾的密码子,而水稻偏爱以T和C结尾的密码子;以RSCU值为基础的聚类结果显示出植物的密码子偏好性具有种族特征,表明基于叶绿体蛋白编码基因的密码子使用特性的聚类结果较适合用于系统发育分析的重要补充.

Codon usage bias studies and cluster analysis on chloroplastic genes in tobacco

Softwares were used to analyze codon usage bias of 6 genes encoded by chloroplast DNA from 3 species in Nicotiana genus and other control species.Results showed that the codon usage in Nicotiana Tabacum was close to that of Nicotiana sylvestris.Among the 59 codons analyzed,39 were totally the same in terms of RSCU(Relative Synonymous Codon Usage) value.30 codons were revealed to be preferable to be used in the CDS(Coding DNA Sequence) of 6 genes encoded in chloroplast from these 8 species.Among these 8 species,the codons of 7 dicotyledon plants tended to end with C while those of rice preferred to end with T or C.Cluster analysis results based on the RSCU value showed that the codon usage bias was related to genes encoded by chloroplast of the plant species.The cluster results of the RSCU from chloroplast genes could be used as a complementary method for systematic developmental analysis.