中文摘要：

密码子使用偏好性是物种在遗传信息传递过程中的一个重要特点，分析物种的密码子使用偏好性对于了解该物种遗传信息的传递规律具有重要意义。原有的密码子偏好性分析主要基于全基因组数据完成。然而由于目前可获得的高等生物全基因组数据有限，使得密码子偏好性分析受到了极大的限制。本研究通过分析赤芝[Ganodermalucidum（Curtis：Fr．）PKarst]全基因组及其液体培养菌丝、原基和子实体大规模转录组数据，发现基于全基因组和转录组数据分析获得的所有氨基酸的最优密码子完全一致。以上研究结果表明，利用大规模转录组数据代替基因组数据分析物种密码子使用偏好性具有可行性。通过计算26个赤芝萜类合酶（terpenesynthase，TS）编码基因中大肠杆菌和酿酒酵母稀有密码子所占比例，发现酿酒酵母稀有密码子在赤芝TS基因中所占比例较高，而大肠杆菌稀有密码子所占比例相对较低，表明赤芝TS基因更难以在酿酒酵母中进行表达。参照酵母最优密码子，利用化学方法全合成Ts基因将是解决外源基因与底盘系统密码子不匹配问题的有效手段。

英文摘要：

Codon usage bias is an important characteristic of genetic information transfer in organisms. Analysis of codon usage bias of different species is important for understanding the rules on genetic information transfer. The previous method for analysis of codon usage bias is mainly based on genomic data. However, this method is greatly limited, because the genome sequences of higher organisms are still not available up to now. In this study, we found that we could obtain the same optimal codons of Ganoderma lucidum （Curtis： Fr.） E Karst based on its whole genomic data or large-scale transcriptomic data from its liquid-cultured hyphae, primordium and fruiting body, separately. This result indicated the feasibility to understand the codon usage bias based on the large-scale transcriptomic data. By calculating the proportion of rare codons of Escherichia coli and Saccharomyces cerevisiae in 26 terpene synthases （TS） of G lucidum, we found that the rare codons of S. cerevisiae have a higher proportion in TS genes, while the rare codons of E. coli have relatively lower, suggesting that the TS genes of G. lucidum are possibly more difficult to be expressed in S. cerevisiae than in E.coli. Chemical synthesis of TS genes according to the yeast optimal codons will be an effective way to solvethe problem on the mismatch of gene codon bias between the foreign genes and the host strain.