自家禽與禽痘病毒疫苗中偵測內源性家禽網狀內皮增生症病毒基因

Abstract

Reticuloendotheliosis virus (REV) is an avian gamma-retrovirus which results in immunosuppression, runting disease and lymphomas. Furthermore, REV has been found as a contaminant of Marek's disease and fowl pox vaccines (FPV). Since REV is well known to integrate into host DNA, the purpose of this study was to detect endogenous REV (eREV) gene in chickens and geese and in a FPV. One REV strain isolated from chickens was used as a template for PCR with specific primers to amplify pol, gag, env, and LTR genes, labeling with Digoxigenin as a probe for detecting eREV in chickens and geese and in one FPV by southern blot hybridization analysis. The DNA samples extracted from 10 Leghorn layers , 10 Arbor Acres broiler breeders, 10 Avian broiler breeders and 10 White Roman geese were used for eREV detection. We isolated REV 3337/05 from chicken. Furthermore, The result showed that no eREV was detected in chickens or in geese. However, one REV 5’ LTR fragment integrated into the FPV in the region between ORFs 201 and 203 was found. This LTR-integration shows no damage to chickens after vaccination clinically because only the FPV carrying a near intact REV is likely to cause tumors in vaccinated chickens. Since only one eREV copy integrating in the FPV was found, this vaccine could be used clinically.