兔出血症病毒基因组克隆与病毒抗原性相关遗传变异分析

Genome cloning and analysis of correlation between antigenicity and genetic evolution of RHDV

RT-PCR获得兔出血热病毒SQ-1株基因组序列,对非结构蛋白与结构蛋白基因序列进行了遗传演变分析,基于各非结构蛋白核苷酸序列同源性尽管存在微小差异,但原始毒株和变异毒株分类结果一致,SQ-1株归属变异毒株,这与以病毒结构蛋白VP60、VP10蛋白基因的分型结果相同;以VP60蛋白分析SQ-1毒株在时间与空间的遗传进化来源,发现核苷酸、氨基酸序列同源性最高的分别是于2009年报道的俄罗斯毒株与2005/2006年我国分离毒株,同时,氨基酸序列同源性在99.3%以上毒株分布于我国、美国、德国与法国等,有的毒株流行时间久远。这说明该病毒的遗传进化比较复杂,决定其进化来源的因素好像与地域分布、流行时间等无关,而是可能与该类型毒株可以在免疫动物体内存活并同源重组有关。同时,分析了RHDVa群毒株目前和未来的遗传变异趋势及其对抗原性的影响,以及RHDVa群与原始群之间遗传演化氨基酸位点差异相关性,初步阐明了我国流行毒株的特点,这对于深入研究变异型病毒的遗传进化机制、防控该病将发挥重要指导作用。

An isolated rabbit haemorrhagic disease virus（RHDV）,SQ-1strain,was propagated through rabbit challenge test.The genome RNA was isolated and the sequences were obtained via RT-PCR and sequencing.Then the sequence comparison was performed based on non-structural proteins and structural proteins,respectively.The RHDVs were divided into original RHDV and RHDVa subgroups after comparing the nucleotide homology of non-structural and structural proteins despite small variance among them,the SQ-1strain belongs to the RHDVa subgroup.The genetic evolution of the SQ-1strain was further analyzed through comparison of the nucleotide and the amino acid sequences,the highest genetic distance from these strains were reported in Russia and China accordingly,furthermore,the strains with more than 99.3%amino acid homology distributed in China,USA,Germany and France,which were isolated several years ago.By which it means the genetic derivation of SQ-1strain is complicated and has no direct correlation with the geographical distribution and the popular time,but may be associated with the virus survival and homologous recombination in immunized rabbits.Then the genetic diversity and its resulting effects on the antigenicity of RHDVa subgroup were analyzed,and the genetic correlation of amino acid residues associated with genetic evolution between the original subgroup and the RHDVa subgroup was also evaluated,by which the epidemic characteristics of pandemic strains in China were clarified preliminarily.The achieved results will benefit the mechanism research on genetic evolution of the RHDVa subgroup and play great roles in the prevention and control of the disease.