Detection of Reticuloendotheliosis Virus Genomic Sequence in The Genome of Field and Vaccine Strains of Fowl Poxvirus
含有禽网状内皮组织增生病病毒基因组片段的天然重组禽痘病毒的研究

Integration of reticuloendotheliosis virus (REV) into the genome of fowl poxvirus (FPV) has been reported recently. In order to determine whether this event has occurred in China, the presence of long terminal repeat (LTR) and envelop (env) gene fragments of REV provirus were detected from genomes of five FPV vaccines and a field isolate. When these six FPV strains were inoculated in the Chicken Embryo Fibroblast (CEF) cells and passed for 5 times respectively, the infectious REV could not be detected in immunofluorescence assay (IFA) with REV specific monoclonal antibody (MAb) 11B118. REV-LTR and REV-env gene fragments were amplified from the DNA extracts of the passage 2 and the passage 5 of FPV-infected CEF cells by PCR for all the 6 strains. Dot blot test proved the presence of LTR and env gene in the FPV-infected cell extracts and the PCR product for REV-LTR and REV-env. The results indicated that stable integrations of REV gene fragments in the genome of FPV vaccine and field strains were very common in China.