Virus-induced cell gigantism and asymmetric cell division in archaea

Studies on bacterial and eukaryotic viruses have revealed a range of strategies used by viruses to subdue host cells for efficient virus replication. How archaeal viruses interact with their hosts remains largely unknown. We characterize a new strategy employed by a nonlytic archaeal virus STSV2 to transform its host into a giant virion-producing factory, whereby the virus infection blocks normal cell division by binary fission, leading to gradual cell growth to unprecedented sizes. The giant infected cells divide asymmetrically by budding, replenishing the pool of susceptible hosts. Thus, although tinkering with the cell cycle is a common practice among evolutionarily unrelated viruses from different domains of life, the mechanisms and manifestation of these actions can be highly diverse and unexpected.