广东新型鸭呼肠孤病毒σB蛋白基因克隆及序列分析

为研究广东新型呼肠孤病毒（NDRV）的基因变异及遗传演化情况，本试验从广东不同鸭场病死鸭肝脏、脾脏等组织脏器中分离到8株流行毒株，用RT-PCR方法进行σB蛋白基因扩增、克隆与序列分析，并与其他毒株σB蛋白的氨基酸特性、蛋白抗原和蛋白基因进行系统进化比对分析。结果表明，广东省鸭群中感染的NDRV与国内其他地区报道的DRV核苷酸序列同源性很高，达96.6%~99.5%，而与禽呼肠孤病毒（ARV）和番鸭呼肠孤病毒（MDRV）的同源性则较低，分别为64.6%~66.5%和66.2%~67.1%；8株NDRV之间的核苷酸序列同源性高达97.7%~99.7%。与其他毒株比较结果显示，本试验分离的NDRV毒株磷酸化位点均比参考毒株ARV和MDRV少，且大多数区域的抗原指数都较高，抗原性与MDRV较为接近，遗传进化分析结果表明，NDRV和国内其他DRV处于独立的进化分支，ARV和MDRV则处于不同分支。结果表明，广东省流行的NDRV毒株σB蛋白基因序列高度保守，且广东地区分离的NDRV与国内其他地区分离的DRV没有明显的地域差异。

Cloning and Sequence Analysis of σB Protein Genes of New-type Duck Reovirus Isolated from Guangdong

In order to study the genetic variation and evolution of new-type duck reovirus (NDRV) in Guangdong province, some samples (liver and spleen) were collected from different sick ducks in Guangdong province. Eight strains were initially isolated and identified. σB protein genes were amplified, cloned and sequenced by RT-PCR method,and σB protein characteristics of amino acid, antigen and genetic analysis of system evolution were compared with other strains. The results showed that the isolated viruses were the NDRV. Comparison of nucleotide sequences showed the NDRV isolated from duck in Guangdong province were more closely related to DRV reported in other parts of the country, the homology reached 96.6% to 99.5%, the NDRV isolated from duck in Guangdong province were not closely related with ARV and MDRV, the homology was 64.6% to 66.5% and 66.2% to 67.1%, respectively. Homology comparison of nucleotide between 8 strains NDRV were 97.7% to 99.7%.Compared with other strains, NDRV phosphorylation sites were less than ARV and MDRV reference strains, and the most area of the antigen index were high, similar to MDRV. Genetic evolution analysis results showed that NDRV and other domestic DRV were in the evolution of the same branch, but ARV and MDRV were in different branches. The result showed σB protein gene sequences of the NDRV were highly conserved,and NDRV isolated from Guangdong province had no significant regional differences with other regions.