湖北地区克氏原螯虾白斑综合征病毒变异区ORF14/15、ORF23/24基因序列比较分析

摘要

试验扩增、克隆了在湖北地区采集的19份克氏原螯虾(Procambarus clarkii)白斑综合征病毒(White spot syndrome virus,WSSV)阳性样品的变异区ORF14/15和ORF23/24基因,通过测序比较分析了湖北各WSSV毒株与GenBank公布的标准毒株间在变异区ORF14/15及ORF23/24基因的差异性.结果显示,19份WSSV阳性样品中有部分样品在变异区扩增出ORF14/15、ORF23/24基因片段,变异区基因序列分析发现,与GenBank已公布的标准毒株相比,存在大片段缺失.在变异区ORF14/15,有3个毒株扩增出1 442 bp的片段,4个毒株扩增出630 bp的片段,基于变异区ORF14/15构建的系统进化树显示,这些毒株归属两个不同的分支.在变异区ORF23/24,有2个毒株扩增出大小为2 096 bp的片段,进化分析发现这2个毒株在变异区ORF23/24的遗传距离较近.%White spot syndrome virus (WSSV)gene variable regions,ORF14/15 and ORF23/24,have been employed as marks in a number of molecular epidemiology,prevalence and evolution studies of WSSV.In this study,19 WSSV positive samples collected from farmed Procambarus clarkii in Hubei were cloned and sequenced for the WSSV Gene variable regions ORF14/15 and ORF23/24 then compared with the sequence of standard WSSV strain posted in GenBank.The results showed that these 19 positive samples were amplified by PCR with specific primers of ORF14/15 and ORF23/24,respectively,and in some of the positive samples the targeted products were generated in gene variable regions ORF14/15 and ORF23/24.After sequencing and multiple alignment analysis,the results showed that there were large segment deletions in the two gene variable regions.In ORF14/15,a product of 1 442 bp in length was amplified in 3 WSSV strains,while a product of 630 bp in length were amplified in another 4 WSSV strains.These WSSV strains were clustered in two different clusters based on ORF14/15 gene phylogenetic tree analysis.In ORF23/24,a product of 2 096 bp in length was amplified in two WSSV strains,the phylogenetic tree analysis showed that these two WSSV strains have a close genetic relationship.