Abstract: A/goose/Guangdong/1/96(GSGD/1/96) is the first highly pathogenic H5N1 avian influenza virus isolated from the mainland of China. It is the HA gene donor of the Hong Kong 97 H5N1 viruses and the ancestor of current H5N1 viruses circulating in the mainland of China. In the present study, the authors have established an eight-plasmid reverse genetics system and rescued GSGD/1/96 (R-GSGD/1/96) through cell transfection. Animal studies confirmed that the rescued virus maintained the biological properties of the wild type GSGD/1/96 virus (W-GSGD/1/96). Both R-GSGD/1/96 virus and W-GSGD/1/96 are highly pathogenic for chickens with intravenous pathogenecity index (IVPI) of 2.01 and 2.10, respectively. The viruses could not replicate in mice, though lower titer viruses could be recovered from the lungs of few mice 1-2 days after inoculated intranasally with 106EID50 of the viruses. The successfully establishment of the reverse genetics system of GSGD/1/96 will enable us to conduct extensive studies of the molecular basis of the evolution of H5N1 avian influenza viruses.

Key words: Avian influenza virus, H5N1, Reverse genetics system