Molecular Epidemiology of Avian Leukosis Virus Subgroup J in Layer Flocks in China
Molecular Epidemiology of Avian Leukosis Virus Subgroup J in Layer Flocks in China
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DOI：
10.1128/jcm.06179-11
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发表时间：
2012-03-01
影响因子：
9.4
通讯作者：
Wang, Xiaomei
中科院分区：
文献类型：
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作者：
Gao, Yulong;Yun, Bingling;Wang, Xiaomei
J亚群禽白血病病毒（ALV-J）于1988年首次从肉鸡中分离到。直到2004年，全世界没有观察到ALV-J感染或蛋鸡肿瘤的现场病例。然而，近年来中国的蛋鸡群经历了这种病毒的爆发。对从产蛋鸡群中分离的ALV-J株进行了分子流行病学调查。77.8%（21/27）的ALV-J产蛋鸡分离株的env基因与ALV-J原型株（HPRS-103）及美国和中国肉用型鸡分离株（命名为ALV-J肉鸡分离株）的env基因差异显著。89.5%（17/19）的ALV-J层分离株3'非翻译区缺失205个核苷酸。约94.7%（16/17）的蛋鸡分离物含有146 - 149个残基的完整E元件。84.2%（16/19）的ALV-J产蛋鸡分离株的U3序列与ALV-J肉鸡分离株的U3序列同源性低于92.5%，但禽逆转录病毒典型的转录调控元件高度保守。在大多数的ALV-J层分离物的env基因，U3区，和E元件的几个独特的核苷酸替换被检测到。这些结果表明，ALV-J蛋鸡分离株的env基因、E元件和U3区进化迅速，与ALV-J肉鸡分离株有显著差异。这些结果将有助于更好地了解ALV-J引起蛋鸡肿瘤疾病的致病机制。
Avian leukosis virus subgroup J (ALV-J) was first isolated from meat-type chickens in 1988. No field cases of ALV-J infection or tumors in layer chickens were observed worldwide until 2004. However, layer flocks in China have experienced outbreaks of this virus in recent years. The molecular epidemiology of ALV-J strains isolated from layer flocks was investigated. The env genes of 77.8% (21/27) of the ALV-J layer isolates with a high degree of genetic variation were significantly different from the env genes of the prototype strain of ALV-J (HPRS-103) and American and Chinese strains from meat-type chickens (designated ALV-J broiler isolates). A total of 205 nucleotides were deleted from the 3' untranslated region of 89.5% (17/19) of the ALV-J layer isolates. Approximately 94.7% (16/17) of the layer isolates contained a complete E element of 146 to 149 residues. The U3 sequences of 84.2% (16/19) of the ALV-J layer isolates displayed less than 92.5% sequence homology to those of the ALV-J broiler isolates, although the transcriptional regulatory elements that are typical of avian retroviruses were highly conserved. Several unique nucleotide substitutions in the env gene, the U3 region, and the E element of most of the ALV-J layer isolates were detected. These results suggested that the env gene, E element, and U3 region in the ALV-J layer isolates have evolved rapidly and were significantly different from those of the ALV-J broiler isolates. These findings will contribute to a better understanding of the pathogenic mechanism of layer tumor diseases induced by ALV-J.