禽脑脊髓炎病毒VP1基因的克隆与序列分析

Cloning and sequence analysis of VP1 gene of avian encephalomyelitis virus

为了揭示禽脑脊髓炎病毒（AEV）的分子特性，使用RT-PCR方法扩增出AEVsD和HB分离株和1株标准鸡胚适应株VR株的VP1基因，克隆到载体pBluescriptSK（-）上，然后进行序列测定，并对这3株AEV的VP1基因与已发表的AEV活疫苗株1143株和强毒株L2Z株进行比较。结果，发现它们之间核苷酸和氨基酸的同源性分别为94．2％～99．9％和98．9％～100．0％。SD株和HB株与鸡胚适应毒VR株的VP1蛋白氨基酸序列完全相同。与1143株和L2Z株比较，VP1蛋白仅存在2～3个氨基酸的差异。结果表明，在不同AEV毒株中，VP1蛋白高度保守，存在极低的抗原性差异，不同AEV毒株的毒力和组织亲嗜性可能与VP1基因无关，VP1蛋白可作为防制AEV潜在的亚单位疫苗和诊断抗原。

To reveal the molecular characteristics of avian encephalomyelitis virus（AEV）,VP1 gene sequences of AEV strains SD, HB and VR were determined. The VP1 genes of two AEV isolates and one standard egg-adapted strain VR were amplified by using RT-PCR,then cloned into the vector pBluescript SK（- ） and sequenced. The sequences of VP1 genes of these three strains were compared with those of the live AEV vaccine strain 1143 and virulent strain L2Z. The results showed that the 94.2%-99.9% nucleic acid identities and 98.9%- 100. 0% amino acid similarities existed among the AEV strains examined so far. The two strains SD and HB had identical amino acid sequences with that of the strain VR. Furthermore,they had only 2-3 amino acid substitutions compared to the strains 1143 and L2Z. The results indicated that AEV VP1 was a highly conservative protein with much low antigenic variation among different strains,and the difference of virulent and tissue-tropism of different AEV strains might not be associated with the VP1 gene,which was used as a potential candidate for subunit vaccine and diagnostic antigen of AEV.