DEVELOPMENT AND APPLICATION OF POLYMERASE-CHAIN-REACTION (PCR) TESTS FOR THE DETECTION OF SUBGROUP J AVIAN-LEUKOSIS VIRUS

Subgroup J avian leukosis virus (ALV) is a recently identified avian r etrovirus associated with myeloid leukosis in meat-type chickens. The env gene of the HPRS-103 strain of ALV, the prototype of this subgroup , differs considerably from that of other subgroups, but shows close h omology to the env-like sequences of members of the EAV family of endo genous retroviruses. Polymerase chain reaction (PCR) tests using two s ets of primers were developed for the specific detection of the member s of this new subgroup along with another pair of primers for detectin g other subgroup viruses. The specificity and sensitivity of this dete ction system was compared with the conventional detection methods in e xperimentally and naturally infected samples. The use of PCR was found to be rapid, specific and more sensitive than the conventional diagno stic tests for the detection of ALV. Moreover, the two subgroup J ALV- specific PCR tests were found to be capable of differentiating between 'prototype-like' viruses and more recent isolates which show extensiv e antigenic and sequence variations. The use of this test as a rapid a nd sensitive method of detection of viruses in epidemiological studies and eradication programs is discussed. (C) 1998 Elsevier Science B.V. All rights reserved.