[Show abstract][Hide abstract] ABSTRACT: Based on the complete genome sequence of Newcastle disease virus (NDV) ZJI strain, seven pairs of primers were designed to
amplify a cDNA fragment for constructing the plasmid pNDV/ZJI, which contained the full-length cDNA of the NDV ZJI strain.
The pNDV/ZJI, with three helper plasmids, pCIneoNP, pCIneoP and pCIneoL, were then cotransfected into BSR-T7/5 cells expressing
T7 RNA polymerase. After inoculation of the transfected cell culture supernatant into embryonated chicken eggs from specific-pathogen-free
(SPF) flock, an infectious NDV ZJI strain was successfully rescued. Green fluorescent protein (GFP) gene was amplified and
inserted into the NDV full-length cDNA to generate a GFP-tagged recombinant plasmid pNDV/ZJIGFP. After cotransfection of the
resultant plasmid and the three support plasmids into BSR-T7/5 cells, the recombinant NDV, NDV/ZJIGFP, was rescued. Specific
green fluorescence was observed in BSR-T7/5 and chicken embryo fibroblast (CEF) cells 48h post-infection, indicating that
the GFP gene was expressed at a relatively high level. NDV/ZJIGFP was inoculated into 10-day-old SPF chickens by oculonasal
route. Four days post-infection, strong green fluorescence could be detected in the kidneys and tracheae, indicating that
the recombinant GFP-tagged NDV could be a very useful tool for analysis of NDV dissemination and pathogenesis.