DETECTION OF AVIAN-LEUKOSIS VIRUS SUBGROUP-J USING THE POLYMERASE-CHAIN-REACTION

A polymerase chain reaction (PCR) assay was developed for the detectio n of avian leukosis virus strain J (ALV-J) in chickens. Primers were b ased in the E element and the 3' terminus of the long terminal repeat of proviral ALV-J. PCR products were amplified from genomic DNA extrac ted from chicken embryo fibroblasts (CEF) infected with either strain HPRS-103, the prototype of ALV-J, or field isolates of ALV-J obtained from broiler breeder hocks in the United States that exhibited myeloid leukosis. The newly developed PCR detected ALV-J in DNA prepared from CEF inoculated with ALV-J but not from CEF inoculated with subgroup A , B, C, D, or E. The PCR also detected ALV-J in DNA prepared from bloo d, combs, and toes obtained from chickens experimentally infected with ALV-J and in DNA obtained from peripheral blood monocytes from natura lly infected broiler breeder chickens. The PCR described here offers a specific and sensitive alternative to conventional virus isolation te sts for ALV-J.