E亚群禽白血病病毒分离株的全基因组序列分析

Whole Genome Sequencing of an Avian Leukosis Virus Subgroup E Isolate

为了弄清江苏省某一地方品种种鸡场病死鸡的死亡原因,采集病死鸡组织,检测显示仅为ALV阳性;通过CEF和DF-1细胞培养、p27抗原检测和间接免疫荧光(IFA)对病毒进行鉴定;对病毒分离株前病毒DNA序列进行全基因组序列测定与分析。结果显示:分离株能够在CEF上生长,上清液中可检测到p27抗原,CEF出现特异性绿色荧光,DF-1细胞培养物以上检测均为阴性,初步表明分离株为ALV-E,命名为JY202106;其基因组大小为7529 bp,符合复制完整型C型反转录病毒特征,缺乏肿瘤基因;序列分析显示,分离株与参考株同源性为84.3%~98.7%,gp85进化分析分离株与ALV-E同属一个进化分支,与ev-1株同源性高达99.2%。研究表明地方品种鸡中存在内源性ALV,为该病的防控提供了参考和依据,也丰富了ALV基因组数据资料。

To determine the cause of death of breeders without significant clinical signs on a chicken farm in Jiangsu province and analyze genomic characteristics and evolution,heart,liver,lungs,kidney and bursa were collected for detection of Avian leukemia virus(ALV).The tissue samples were inoculated onto CEF and DF-1 cells.The results showed that the virus isolate was only cultured on CEF cells and the p27 antigen was detected in the supernatant.The inoculated CEF cells showed specific green fluorescence in indirect immunofluorescence assay.The isolated virus was designated as JY202106 isolate.The whole genome of this isolate was sequenced with the full length of 7529 nt,which had a genetic organization typical of replication-competent C retroviruses lacking oncogenes.In addition,sequence analysis showed that the JY202106 isolate shared 84.3%-98.7%nucleotide homology of the whole genome with the subgroup reference strains.The gp85 gene of the JY202106 isolate had the highest identity to that of ev-1,the prototype of ALV-E.This study provided additional data for understanding the genetic evolution of ALV and provided a reference for ALV prevention and control.