|Smith, Eugene - RETIRED ARS EMPLOYEE|
|Williams, Susan - MICHIGAN STATE UNIVERSITY|
Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 12, 1998
Publication Date: N/A
Interpretive Summary: Avian myelocytomatosis, a cancer-like disease of chickens induced by a novel subgroup-J avian leukosis virus (ALV-J), has emerged as a serious cause of mortality and other production problems in broiler breeder chickens. Virtually all United States broiler breeder companies are experiencing problems associated with ALV-J infection. Furthermore, methods that have been successful in eradicating other subgroups of ALV infection in white leghorn breeders appear to be less effective in controlling ALV-J infection in broiler breeder strains. A polymerase chain reaction (PCR) test, a molecular technique that can be used to amplify the DNA of disease agents, to detect ALV-J in blood and other tissues of affected chickens was developed. The newly developed PCR test offers a specific and sensitive alternative to conventional virus isolation tests for ALV-J. Using the PCR test, broiler breeder companies will be able to control virus infection in their breeder flocks by selective breeding from virus-negative hens and by ensuring that progeny chicks are also free from virus infection.
Technical Abstract: A polymerase chain reaction (PCR) assay was developed for the detection of avian leukosis virus (ALV), strain J in chickens. Primers were based in the E element and the 3' terminus of the long terminal repeat of proviral ALV-J. PCR products were amplified from genomic DNA extracted from chicken embryo fibroblasts (CEF) infected with either strain HPR-103, the prototype eof ALV-J, or with field isolates of ALV-J obtained from broiler breeder flocks that exhibited myeloid leukosis in the United States. The newly developed PCR detected ALV-J in DNA prepared from CEF inoculated with ALV- J, but not from CEF inoculated with subgroups A, B, C, D or E. The PCR also detected ALV-J in DNA prepared from blood, combs and toes obtained from chickens experimentally infected with ALV-J and in DNA obtained from peripheral blood monocytes from naturally infected broiler breeder chickens. The PCR described here offers a specific and sensitive alternative to conventional virus isolation tests for ALV-J.