摘要
为了分析鲨烯合酶（squalenesynthase，ss）基因密码子的使用方式及其影响因素，利用codonW和SPSS16．0软件对47条来自不同物种的嬲基因进行多元统计分析、对应性分析。髂基因密码子1～3位碱基的GC含量（GC1，GC2和GC3）依次为51．33％、34．65％和54．37％，3个位点的GC含量均呈极显著相关关系（p〈0．01），对应性分析的结果表明，第1轴显示30．71％的差异，有效密码子数和GC3、GC1和GC2的均值与GC3之间的相关性均达极显著水平（p〈0．01）。筛选出的26个最优密码子的第3位碱基均为G或C。以MEGA5．0构建的基于SS蛋白质序列的进化树比基于RSCU的聚类更符合传统的系统发育观点。SS基因密码子偏好以G／C结尾，使用模式受选择和突变影响，突变对密码子偏好影响较大。
To analyze the codon usage of squalene synthase （SS） gene and the influence factors, multivariate ana- lysis and corresponding analysis of SS genes from different species were analyzed by software codon W and SPSS 16.0. GC content at three positions ofcodons （GC1, GC2 and GC3） in turns was 51.33%, 34.65% and 54.37%, and corresponded significantly. GC 1 and GC2 have a significant correlation coefficient （p 〈0.01）. Corresponding result showed that, Axis 1 showed 30.71% variation. Effective number of codons （ENC） and GC3 were significantly correlated （p 〈0.01）. The correlation between GC 12 and GC3 were significant （t9 〈0.01）. 26 synonymous codons were the optimum eodons which were all ended by C or G. The 3rd base composition preferred G/C in SS genes. Compared with cluster analysis dendrogram of RSCU for SS genes, the evolutionary tree build based on protein sequences encoded by SS genes through MEGA 5.0 software fit traditional viewpoint higher. The third position for all codons in SS preferred to end with A and T. Synonymous codon usage pattern formed under effect of mutation pressure and natural selection, mutation pressure influenced higher in SS gene.
出处
《基因组学与应用生物学》
CAS
CSCD
北大核心
2013年第2期232-239,共8页
Genomics and Applied Biology
基金
国家自然科学基金(30701086)
河北省自然科学基金(C2009001252)
河北省自然科学基金-石药集团医药联合研究基金(H2012401006)共同资助
关键词
鲨烯合酶
密码子偏性
多元分析
聚类分析
Squalene synthase, Codon usage bias, Multivariate analysis, Cluster analysis
