[目的]探讨地方品种皖南黄肉种鸡群中禽白血病病毒(ALV)与禽网状内皮增生病病毒(REV)的感染状态,同时对J亚型ALV(ALV-J)分离株的囊膜糖蛋白基因(env)和非编码区3'UTR序列进行分子变异分析,并对近十年的分离株非保守序列区段进行统计比较,探讨ALV-J分子变异趋势.[方法]取7只300日龄皖南黄肿瘤病鸡分别进行病理组织学观察、IFA检测肝脏组织切片后激光共聚焦观察、细胞培养后的IFA以及PCR方法检测.[结果]7只皖南黄肉种鸡有6只同时感染ALV-J与REV,而且ALV-J和REV已经共感染同一个肝细胞.取2个ALV-J分离株进行env基因与非编码区YUTR扩增与序列分析,两分离株的env全长均为1704 bp,3'UTR全长均为400 bp,YUTR区段rTM和E元件同发生双缺失;3'UTR-E元件与近十年国内来自白羽肉鸡的ALV-J分离株比较,基因缺失表现为共性,但3'UTR-rTM基因缺失呈现多样性;5'LTR作为保守序列较之前所有国内外毒株有11 bp缺失.[结论]研究发现,地方品种皖南黄肉种鸡群存在ALV-J与REV的共感染,且呈现普遍性(6/7),表明地方品种鸡高肿瘤发生率与ALV-J、REV共感染密切相关;ALV-J的基因缺失主要集中于YUTR-E与YUTR-rTM,3'UTR-E元件基因缺失显示,皖南黄肉种鸡群ALV-J分高株与近十年国内来自白羽肉鸡的ALV-J分离株有共同的来源.%The objective of the study is to explore co-infection of reticuloendothelial hyperplasia virus (REV)and avian leukemia virus (ALV) in Wannan yellow feather broilers. In addition, the sequence variations in the envelope glycoprotein gene (env) and the 3'UTR and the 5'LTR non-coding sequences of ALV-J collected in the last decade were analyzed. Seven 300-d old chickens suffering from neoplastic diseases were subjected to histopathology examination. Cell cultures were established for viral detection and quantification using PCR and IFA. The result showed that 6 of the 7 animals were co-infected with both viruses,while ALV-A and ALV-B were not detected. Furthermore, both viruses were detected in the same liver cells. Sequence analysis showed that the full-length of the env gene and the 3'UTR region were 1 704 bp and 400 bp, respectively, and both the rTM and the E elements in the 3'UTR region were deleted. Sequence comparison showed that the deletion of the 3'UTR-E element of ALV-J from Wannan yellow-feather broilers is also shared among the ALV-J isolates collected by the authors from the white-feather broilers in the past decade, whereas the deletion of the 3'UTR-rTM element was variable. The 5'LTR conserved sequence had an 11 bp deletion compared to the previously analyzed strains. The remarkably high frequency (6/7) of REV and ALV-J co-infection in association with the high tumor occurrence in Wannan yellow-feather chickens suggest that such co-infection may be an important contributing factor for the tumor epidemic. The fact that the deletion in the 3'UTR-E element is shared by the ALV-J isolates from both Wannan yellow-feather broilers and the white-feather broilers indicates that these ALV-J isolates are of a common origin.
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