ABSTRACT
The envelope gene of ADOL-4817 strain of avian leukosis viru s subgroup J (ALV-J) was amplified by polymerase chain reaction （PCR） and clo ned into TA vector. The sequence analysis results showed that the envelope gene is composed of 1?746 bp, 1?554 bp of which could be translated into 517 amino acids for gp85 and gp37. The molecular weight of envelope protein is 57.7kD. T here are 15 potential glycosylation sites in the envelope protein, 13 of which i s located in gp85. Analysis of sequences of envelope gene indicate that ADOL -4817 showed high degree of sequence identity to other ALV-J strains, and m ost close ly related to the like-envelope gene of endogenous virus EAV-HP but divergent from these of other ALV subgroup A-E . These data support the hypothesis that envelope gene of avian leukosis virus subgroup J maybe acquired by recombination with expressed sequences.