288株猪圆环病毒的序列比较及遗传进化分析

目的为进一步了解猪圆环病毒(Porcine circovirus,PCV)的遗传进化规律,为该病的预防和控制奠定基础。方法对来自世界各国的26株PCV1和262株PCV2的全序列用生物软件进行了核苷酸的同源性比较,并对其ORF1和ORF2进行了核苷酸和推导氨基酸的比较。结果从核苷酸水平来看,PCV1与PCV2明显分为两支,PCV1间分布没有规律,而PCV2间又分为以来自美国、加拿大、澳大利亚的序列为代表的亚型Ⅰ和以来自法国和新西兰的序列为代表的亚型Ⅱ;但从氨基酸水平来看,其分型并没有规律可循。从遗传进化树可以看出,PCV2的分布并没有地域性和时限性。数据统计显示,尽管相隔近十年之久,但其同源性并没有发生太大的改变,可见PCV2相当保守。另外对PCV2的碱基和氨基酸突变位点进行统计发现,PCV2序列间更倾向于碱基的颠换,但并无单个碱基和氨基酸的偏好性。结论PCV2相对保守,地域性和时限性分布不明显。

Sequences Comparison and Phylogenetic Tree Analysis of 288 Strains of Porcine Circovirus

In order to know the heredity disciplinarian of porcine circovirus(pcv) and pave the basement for preventing and controlling the disease.In this research,nucleotide sequences of 26 strains of PCV1 and 262 strains of PCV2 were analyzed,also,the ORF1's and ORF2's nucleotide sequences and deduced amino acid sequences were analyzed.At the nucleotide level,the results show that PCV1sequences and PCV2 sequences were divided into two different branches,and among the PCV1 sequences there were no obvious regularity,but among PCV2 sequences,there were divided into two different sub-gene types.The sub-gene typeⅠwas mainly consisted of sequences from American,Canada and Australia,and the sub-gene typeⅡwas mainly consisted of sequences from Franch and Newzealand.At the amino acid level,the phylogenetic tree was very complexity,and there were no obvious regularity.It was found statistically that,although nearly ten years pasted, the sequences homology of PCV had no large changes,the results showed that PCV was very conserved.After analyzed the phylogenetic tree,we discovered that the distributing of PCV had no geographic and time restriction.Also,we analyzed the mutant dots of the PCV2 nucleotide sequences and deduced amino acid sequences,we discovered that,PCV2 nucleotide sequences were easy to has base transversion.