猪圆环病毒同义密码子的使用模式及其影响因素

Patterns and Influencing Factors of Synonymous Codon Usage in Porcine Circovirus

[目的]揭示猪圆环病毒(PCV)基因组的进化特点和遗传多样性。[方法]通过计算PCV基因组的相对同义密码子使用频率(RSCU)、有效密码子数目(ENC)和核苷酸含量等指标,对PCV基因组的密码子使用模式进行了综合分析。[结果]PCV基因组具有较低的GC含量和低的密码子偏好性,不同基因型的PCV在密码子使用上具有显著差异,并且PCV与圆环病毒科中的其他病毒的密码子使用模式也存在差异。PCV与其宿主的密码子使用模式存在一定程度的相似性。此外,地理因素、蛋白质总的平均疏水性和芳香性等可能与PCV的密码子使用模式的形成有关。[结论]PCV基因组的密码子使用模式的形成是突变压力与自然选择相互作用的结果。该研究对阐明PCV的密码子使用规律以及分子进化过程提供了最新的信息。

[ Objective] To reveal the molecular evolution and genetic diversity of Porcine Circovirus（PCV）. [ Method] Comprehensive analy- sis on codon usage pattern in the PCV genome was carried out by calculating relative synonymous codon usage （RSCU） , effective number of cudons （ENC）, dinucleotides and nucleic acid contetlt of the PCV genome. [ l^esult] PCV genomes have relatively lower content of GC and codon preference. Codon usage patterns of PCV of various genotypes changed greatly and significant differences in codon usage patterns of each virus of Cireoviridae. There is much comparability between PCV and its }lost in their synonymous eodon usage. Furthermore, geographic fac- tors, the general average hydrophobicity and the aromaticity may be related to the formation of codon usage patterns of PCV. [ Conclusion ] Synonymous codon usage pattern of PCV genome may be fiwmed as a result of interaction between mutation pressure and natural selection. The information from this study may not only have theoretical value in understanding the characteristics of synonymous codon usage in PCV ge- nomes, but also have significant value for the molecular evolution of PCV.