Abstract/Summary

Phaeoviruses infect the brown algae, Phaeophyceae. They exploit a Persistent evolutionary strategy via genome integration and are the only known representatives to do so amongst the giant viruses, Megaviridae. This review brings together for the first time new knowledge on phaeovirus prevalence and alternative strategies of infection, and highlights how exceptional phaeoviruses are compared to most host-virus systems. Given what we now know about phaeoviruses, unlocking the hidden diversity within other seaweed systems has the potential to fundamentally change concepts within Virology, while significantly impacting on the seaweed industry.