Marine diatom viruses and their hosts: Resistance mechanisms and population dynamics
Tomaru, Yuji; Toyoda, Kensuke; Kimura, Kei
Abstract Viruses infecting diatoms might be primary agents in shaping diatom population dynamics. Diatom viruses were discovered as recently as a decade ago. Since then, data on diatom viruses have rapidly accumulated. At least 18 diatom viruses have been isolated and characterized. They are broadly divided into 2 groups based on genome conformation: ssDNA (Bacilladnavirus) or ssRNA (Bacillarnavirus) viruses. They are icosahedral, <40 nm in diameter, and lack a tail. Viral infection imparts fatal damage on the host in axenic culture. However, in nature, diatom host populations maintain their sizes despite the presence of the infectious viruses, implying diverse virus resistance strategies. We summarise basic features of isolated diatom viruses and propose a diatom host–virus relationship in natural marine environments.