Construction and Characterization of Recombinant CVI988 Expressing the Green Fluorescent Protein

The US2 gene nonessential for viral replication was amplified by polymerase chain reaction(PCR)with DNA from CEF cells infected by MDV vaccine strain CV1988 as template，and was cloned into T-easy vector；Th e expression cassette including GFP gene controlled by CM V promoter and enhancer was cloned into US2 gene to give rise to a tran sfer vector pGUS2GFP,then the complex of pGUS2GFP and DOTAP was transfected into CEF cells infected CVI988 strain virus．Recombinan t rCVIGFP expressing the green fluorescence protein was selected an d purified．Th e characterization of recombinant virus was evaluated n vivo and in vitro．Th e growth curve of recombinan t virus having EGFP gene are similar to that of the parent viru s in CEF cells．Th e recombinat virus expressing GFP could infect chicken and be reisolated from the chickens following intra-abdominal inoculation of rCVIGFP