Modeling the dynamics of multipartite viruses

Most viruses transmit their genetic material in a single package, such that when a cell is infected by a virion, all the information needed for replication is available and the virus replicates. However, some viruses, known as multipartite viruses, have their genetic material contained in several different viral particles. In this case, a cell needs to be infected with at least one copy of each package in order to have all the information needed for viral replication. Requiring infection by multiple distinct particles would seem to present a barrier to successful viral replication, so should be an evolutionary dead end. Yet multipartite viruses exist and seem able to persist. We use mathematical modeling to explore the effect of having multiple viral particles on a virus' ability to establish and maintain an infection. We find that viruses split into more particles require a higher infection rate in order to establish an infection. These findings can help develop an understanding into the adaptive mechanisms of multipartite viruses and contribute to a broader understanding of viral evolution and host-virus interactions.