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目的:最近,有越来越多的SARS-CoV病毒基因组序列释放到GenBank数据库中。我们这项研究的目的是通过分析病毒基因组的变异揭示病毒的进化规律。方法:我们从GenBank数据库中获得20条SARS-CoV病毒基因组序列,计算病毒基因非同义突变频率(K_a)和同义突变频率(K_s)之比。结果:复制酶ORE1a,ORF1b和spike蛋白基因的K_a/K_S之比分别是0.94(p=0.4606),0.38(p=0.0074),0.48(p=0.0685)。结论:SARS CoV复制酶ORF1b在宿主体内正在经历负选择;这种负选择的力量可能也作用于Spike基因。这一发现为治疗SARS药物和抗SARS疫苗研制提供了新的基础。
PURPOSE: Recently, more and more SARS-CoV viral genome sequences have been released into the GenBank database. The purpose of our study is to reveal the evolutionary pattern of the virus by analyzing the variation of the viral genome. Methods: We obtained 20 SARS-CoV genome sequences from GenBank and calculated the ratio of non-synonymous mutation (K_a) and synonymous mutation (K_s). RESULTS: The K_a / K_S ratios of ORE1a, ORF1b and spike protein genes of replicase were 0.94 (p = 0.4606), 0.38 (p = 0.0074) and 0.48 (p = 0.0685), respectively. CONCLUSIONS: SARF CoV replicase ORF1b is undergoing negative selection in the host; this negative selection power may also act on the Spike gene. This finding provides a new basis for the treatment of SARS drugs and the development of anti-SARS vaccines.