【摘要】 用幼鸡成纤维细胞繁殖鸡传染性法民囊病病毒（IBDV）天水（Ts）毒株和CJ-801毒株。用提纯的病毒颗粒提取基因组RNA。根据已报道的IBDV英国52／70株的序列设计引物，用反转录－聚合酶链式反应（RT-PCR）进行cDNA扩增，获得的两个1558bp的片段分别克隆于pGEM-T载体，亚克隆后进行序列分析，并与已报道的4株IBDV的VP2基因的核苷酸序列及推导的氨基酸序列进行了比较。结果表明，不同毒株间核苷酸同源性介于97．75％～99.68％之间，其中Ts与CJ-801以及Ts、CJ-801与CuI、PBG69间的同源性最高，为98．99％。不同毒株间推导的氨基酸同源性介于97．98％～98．99％之间。其中Ts与CJ-801以及Ts、CJ-801与CuI、PBG98间的同源性最高，为98.99％。Ts与CJ-801高变区内两个亲水区域与其它标准Ⅰ型毒株完全相同，而在致病毒株中保守的325～332位7肽区中，Ts和CJ-801的第5位丝氨酸突变为精氨酸，说明Ts与CJ-801为标准Ⅰ型弱毒株。更多还原

【Abstract】 The infectious bursal disease virus Ts strain and CJ-801 strain were propagated in 10-day-old specific-pathogenfree chicken embryo fibroblast Viral dsRNA was extracted and puritied. A Pair of primers was designed according to the segment A sequence of IBDV 52/70 strain rePOrted previously. Two separate cDNA fragmentS in length 1558hp were synthesize and amplified by RT-PCR. The PCR products were cloned intO PGEM-T vector and further subcloned into the vectors pGEM-7Zf. The compndive analysis indicated that the isolates are all closely relayed, ranging from 97J5 % to 99.68 % homologous. The Ts, CJ-801 and PBG98 isolates are the most identical with 99.68 % homology. Present sequence homology of the deduced afnino acids of the VP2 gene of the isolates ranging from 97.98 % to 98.99 %. The Ts, CJ-801, Cul, PBG98 isolates are the most identical with 98.99 % homology. In addition, the amino acids sequence of two hydrophilic regions in the variable region of VP2 was wholly conserved among the isolates, but a su bstitution from the third serine to arginine occurred in the heptCrpeptide which might be resPOnsible for the pathogenicity of IBDV strains in Ts and CJ-801 strains be standard serotype Ⅰstrain and have low pathogenicity.更多还原