[The identification and sequence analysis of ALV-J isolated from layers].

Two Avian leukosis viruses of subgroup J(ALV-J)were isolated from layers by inoculating the sample into chicken embryo fibroblast(CEF)cells and by indirect fluorescent assay(IFA)with ALV-J specific monoclonal antibody JE-9.Sequence comparison indicated the gp85 identities were only in the ranges of 83.4%-87.3% compared with five international reference strains and 86.4%-89.6% compared with eight Chinese strains isolated from white meat-type chickens.The gp37 identities were in the range of 91.8-96.4% compared with the five international strains and 93.4-95.9% compared with the eight domestic strains.When compared with the above thirteen strains,two layers' isolates were more close to the prototype HPRS-103 and had less deletion in 3'-Ter than those strains.All strains isolated from white meat-type chickens in China had a deletion in the "E" region of 3'-Ter except these two isolates,suggesting these two ALV-J isolates from layers have different evolution origins from other Chinese isolates from white meat-type chickens.