Plasmid-like dynamics of persistent RNA viruses in the host fungal population

Abstract

While RNA viruses are generally known for their ability to infect cells from the extracellular environment, a substantial diversity of RNA viruses, particularly those that persistently infect fungi, lack such infectivity. The ecological success and evolutionary maintenance of these persistent RNA viruses remain poorly understood. In this study, we experimentally demonstrate how a non-infectious RNA virus is transmitted and stably maintained within specific fungal host lineages. The revealed mechanism resembles the inheritance strategies of plasmids, highlighting a fundamentally different viral lifestyle that does not rely on extracellular horizontal transmission. These findings advance our understanding of virus-host interactions beyond the classical infection model and shed light on the evolutionary flexibility of RNA viruses.