Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2000
Publication Date: N/A
Citation: Interpretive Summary: Marek's disease (MD), the most common cancer-like disease of chickens is caused by a herpesvirus (MDV). Understanding the role of MDV in induction of disease is an important factor in designing programs for control of this important disease of chickens. Reliable, specific and inexpensive methods for detecting and quantifying MDV in infected chickens are needed in order to study the interaction between the virus and host. We have developed an inexpensive DNA-based technique termed quantitative-competitive polymerase chain reaction (QC-PCR) that proved to be specific for detecting MDV. The test should be a useful tool for estimating the growth of MDV in various organs of chickens. Based on ability of MDV to replicate in various chicken tissues, the new test will allow scientists to predict the disease outcome of various isolates of MDV.
Technical Abstract: We have developed a quantitative-competitive polymerase chain reaction (QC-PCR) for the detection of Marek's disease virus (MDV) DNA. The assay utilizes a competitor DNA that differs from the viral DNA of interest by having a small insertion. The competitor DNA acts as an internal standard for the estimation of viral DNA in an unknown sample. We used this assay to study if there was a correlation between virulence and virus replication. Our data showed that more pathogenic strain of MDV (648A) replicate better in thymus during cytolytic infection than the less pathogenic one (GA). However, no differences in virus titer were observed when these two viruses were grown in tissue culture. Our data is consistent with the general idea that hot strains of MDV replicate earlier and better in the birds. This QC-PCR is extremely specific and sensitive to measure MDV DNA over a wide range.