Reverse genetics systems for the generation of segmented negative-sense RNA viruses entirely from cloned cDNA

Reverse genetics is defined as the generation of virus entirely from cloned cDNA. For negative-sense RNA viruses, whose genomes are complementary to mRNA in their orientation, the viral RNA(s) and the viral proteins required for replication and translation must be provided to initiate the viral replication cycle. Segmented negative-sense RNA viruses were refractory to genetic manipulation until 1989. In this chapter, we review developments in the reverse genetics of segmented negative-sense RNA viruses, beginning with the in vitro reconstitution of viral polymerase complexes in the late 1980s and culminating in the generation of Bunyamwera and influenza virus entirely from plasmid DNA almost a decade later.