Narrowed host ranges do not constrain future host range expansion in RNA phage Φ6

Abstract

The consequences of RNA virus specialization on a virus’s future evolutionary potential are not well understood. This study addresses the gap in the literature by investigating the mechanisms of viral host range re-expansion using a model RNA virus. We found that RNA viruses readily re-expand their host ranges to infect both novel and previously accessible hosts, both by mutational reversion and secondary mutations. Investigating these evolutionary mechanisms improves understanding of recurring host shifts and spillback events, which occur often in nature.