Submitted to: International Marek's Disease Symposium Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 7, 1996
Publication Date: N/A
Technical Abstract: Both avian leukosis virus (ALV) and especially reticuloendotheliosis virus (REV) can induce tumors that are indistinguishable from Marek's disease virus (MDV) induced tumors. Thus, field diagnosis of Marek's disease based upon gross and histological examinations can sometimes be problematic. We recently reported a polymerase chain reaction (PCR) procedure to amplify the 132 bp repeat region of the MDV genome. The amplification was sensitive, simple, and shown to be specific for serotype 1 MDV DNA. We wished to determine whether the PCR-based detection of the MDV genome could be correlated with the appearance of lesions in different tissues. One-day-old 15I5 x 71 chickens were inoculated with intra-abdominally with 10**3 PFU of JM/102 virus. At various intervals, birds were sacrificed and examined grossly for lesions. Tissues were also harvested for histological analysis. DNA extracted from the tissues was PCR amplified with primers specific for the serotype 1 gB gene. Results indicate that the buffy coat becomes PCR positive by 5 days and remains positive at least through 28 days. Both thymus and bursa contain the virus at 5 days, as well. Except for the liver, all tested tissues from 14 days on generally contained the MDV genome. Histological lesions first appeared at 14 days post-inoculation in the gonads, kidney, liver, and peripheral nerves. In general, there was good correlation between the appearance of lesions and a positive PCR amplification.