The reverse genetic system(RGS)is to get the genome of virues, construct cDNA clone which inserted the promoter of RNA polymerase , transcript into virus’s RNA in vitro, then infect host cells or sensitive cells and a mount of virus as parent were proliferated.Reverse genetics manipulation technique or rescue of virus is the technique of reverse genetic system. The reverse-genetic technique is to recover viruses from cloned cDNA provides a way not only to investigate the function of virus proteins a...