丙型肝炎病毒5个基因的正选择位点研究

Assay on the positively selected sites of five genes of hepatitis C virus

按照时间和亚型筛选丙型肝炎病毒5个主要基因(E1、E2、NS3、NS5A和NS5B)的正选择位点,并分析其变化规律。研究结果表明这些基因在总体上均受到纯化选择压力(平均ω<1),且大小依次是E2<E1<NS5A<NS5B<NS3;进一步的分子进化分析鉴定出多个正选择位点,且随着时间的变化,每个基因的正选择位点并非恒定,数目不断增加,位置不断更替;同一基因三个亚型间的正选择位点也不尽相同,1a亚型的正选择位点数目最多,1b亚型次之,3a亚型最少,这些结果使得对HCV的进化规律有了进一步的理解。

The positively selected sites for the five major genes（E1,E2,NS3,NS5A and NS5B）of HCV were analyzed from the perspective of time and subtype,and the pattern of variation of these positively selected sites was studied.The Result of this assay showed that the five genes were generally subject to purifying selection（mean ω1）,and the order of the purifying selection pressure on them was E2E1NS5ANS5BNS3.Through molecular evolution analysis,lots of positively selected sites were detected,and these positively selected sites of HCV were not always same in different periods.The number of them was increasing and the position was constantly changing over time.Besides,in different subtypes,the number and the position of positively selected sites were also not same completely,the number was largest for subtype 1a,followed by subtype 1b,and subtype 3a was the minimum.