传染性法氏囊病超强毒Gx株的致弱研究  

The Attenuation of vvIBDV Gx Strain

作　　者：曾祥伟[1] 王笑梅[2] 高宏雷[2] 付朝阳[2] 魏萍[1] 

机构地区：[1]东北农业大学 [2]中国农业科学院哈尔滨兽医研究所,黑龙江哈尔滨150001

出　　处：《中国预防兽医学报》2003年第2期140-144,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：欧盟合作项目ERBIC18CT980 330

摘　　要：本研究成功将鸡传染性法氏囊病超强毒vvIBDVGx株通过SPF鸡胚的快速培育及鸡胚成纤维细胞传代致弱 ,揭示了vvIBDV从超强毒力向弱毒力转化过程中 ,其主要结构蛋白VP2基因核苷酸及推导的氨基酸序列的变化规律。对不同代次细胞毒进行了序列分析 ,发现细胞毒在第 7代以前 ,VP2基因序列没有改变 ,与欧洲标准超强毒氨基酸同源性达 10 0 % ;细胞毒第 8代 ,有个别核苷酸发生了改变 ,但没有影响氨基酸序列 ;细胞毒第 9代是变化复杂的过渡代 ;10代毒VP2基因与欧洲标准弱毒Cu_1氨基酸序列同源性达 97% ;以后的细胞适应毒至 2 0代 ,其VP2基因序列不再改变。致病性实验表明原代毒对 4周龄SPF鸡致死率为 6 4 % ,细胞毒第 5代的致死率为 6 0 % ,而 2 0代毒对鸡无致病性 ,在鸡体内连续传代Very virulent infectious bursal disease virus (vvIBDV) Gx strain with high pathogenicity was attenuated through replicating in SPF embryo and CEF. The change pattern of VP2 nucleotide and the deduced amino acid sequences were obtained from this strain of vvIBDV,during the process of attenuation. The results of sequencing , analyzing of every generation viruses showed that there was no changes on VP2 gene before 7th generation, there was a few changes in VP2 gene but not on amino acid at 8th generation , the homology of amino acid sequence with European reference vvIBDV strain was up to 100%;The virus of 9th generation was an intermediate with complex changes. 10th generation had become cell_adapted strain, the homology of amino acid sequence with European reference IBDV attenuated strain Cu_1 was up to 97%. VP2 gene did not changed any more from 10th to 20th generation. The results of pathogenicity tests showed that the original (Gx) was typical vvIBDV with the mortality up to 64%, the virus of 5th generation was still vvIBDV with the mortality up to 60% in 4_week_old SPF chickens, while the virus of 20th generation was no pathogenicity and could not atavistic after propagated 6 generation in SPF chickens.

关 键 词：鸡传染性法氏囊病超强毒 传代致弱 VP2 基因 VVIBDV Gx株 

分 类 号：S858.312.6[农业科学—临床兽医学]