Infectious Subgenomic Amplicons method to expedite reverse genetics of SARS-CoV-2 and other coronaviruses

Abstract

There is a need for simple reverse genetics methods to decipher the biological properties of animal and human coronaviruses. Here, we attempted to rescue the recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the Feline enteric coronavirus (FeCoV) using the rapid “Infectious-Subgenomic Amplicons” (ISA) method. For each virus, transfection into permissive cells of eight overlapping subgenomic cDNA fragments covering the entire genome allowed reconstruction of the complete virus genome and generated infectious viral particles. Rescued viruses replicated the phenotypic and genotypic characteristics of the original isolates. In conclusion, the ISA method, which had been previously used for RNA viruses with shorter genomes (e.g., flaviviruses, alphaviruses and enteroviruses) can be used to rescue viruses with substantially longer genomes and usefully complements pre-existing methods for reverse genetics of coronaviruses. Its extreme simplicity and versatility makes it a strong option to decipher the biological properties of coronaviruses circulating in human, domestic or wild fauna populations.