Skip to main content
ARS Home » Research » Publications at this Location » Publication #136805
Title: COMPARISON OF CHINESE FIELD STRAINS OF AVIAN LEUKOSIS SUBGROUP J VIRUSES WITH PROTOTYPE STRAIN HPRS-103 AND U.S. STRAINS

Author
item CUI, ZHIZHONG - SHANDONG UNIV P.R. CHINA
item DU, YAN - SHANDONG UNIV P.R. CHINA
item ZHANG, ZHI - SHANDONG UNIV P.R. CHINA
item Silva, Robert

Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2003
Publication Date: 12/31/2003
Citation: Cui, Z., Du, Y., Zhang, Z., Silva, R.F. 2003. Comparison of chinese field strains of avian leukosis subgroup J viruses with prototype strain HPRS-103 and U.S. strains. Avian Diseases. 47:1321-1330.

Interpretive Summary: Eight different strains of avian leukosis virus, subgroup J, (ALV-J), the causative agent of an economically important cancer-like disease of meat-type chickens, were isolated in the People's Republic of China. When these strains were examined. it was discovered that all the Chinese isolates were closely related to one of the first ALV-Js, first isolated in 1989. The Chinese strains were not that closely related to the current strains of ALV-J in the U.S. This finding is surprising since China imports most of their breeding stock from the U.S.; the information will help the broiler breeder industry in their effort to eradiate ALV-J.

Technical Abstract: Eight Chinese field strains of subgroup J avian leukosis viruses (ALV-J) were isolated from broilers or breeders during January, 1999 to April, 2001. One of them, SD9902, was an acute transforming virus and able to induce typical myelocytomatosis in 22-38 days after inoculation of 1-day-old meat-type chicks. Their envelope protein and 3'UTR were compared with the UK prototype HPRS-103 and several US field strains isolated in 1993-1997. All the Chinese strains shared an almost identical deletion with the US strain 4817 in "E" element region of 3'UTR when compared to prototype HPRS-103, indicating that they have a very close phylogenic relation and the "E" element may not be necessary to the acute transforming ability of ALV-J. Every year, China imports grand-parent breeders of meat-type chickens, mainly from United States. Chinese isolates should represent a part in the phylogenetic tree of US ALV-J evolution. Envelope protein gp85 amino acid sequence analysis demonstrated that, interestingly, all recent Chinese isolates were more closely related to HPRS-103 and the earliest US isolates but drifted away from the late US isolates. The result implies that envelope gp85 has not diverged from the prototype and old strains in a long period.