Cyanobacterial viruses exhibit diurnal rhythms during infection

• DOI: 10.1073/pnas.1819689116
• Publication Date: 2019-06-25T13:13:29Z
• Authors: Riyue Liu; Yaxin Liu; Yue Chen; Yuanchao Zhan; Qinglu Zeng
• Keywords: Gene Expression Regulation, Viral; Synechococcus; 0301 basic medicine; Light; Photoperiod; Biological Sciences; Virus Replication; Light-dark cycle; Virus; Circadian Rhythm; 3. Good health; 03 medical and health sciences; Virus Diseases; 13. Climate action; Cyanophage; Host-Pathogen Interactions; Diurnal rhythm; Bacteriophages; 14. Life underwater; Photosynthesis; Cyanobacterium; Prochlorococcus

Significance

To adapt to the daily light–dark cycle, diurnal rhythms are used by the photosynthetic cyanobacteria Prochlorococcus and Synechococcus , which are the most abundant photosynthetic organisms on earth. Field studies revealed that cyanobacterial virus (cyanophage) populations in the oceans showed transcriptional rhythms. To explore the underlying mechanism, we used cyanophage laboratory cultures to find that some showed adsorption rhythms and all showed transcriptional rhythms. We discovered that the cyanophage transcriptional rhythm is partially caused by the photosynthetic activity of host cells, explaining transcriptional rhythms of field cyanophage populations. Our study shows that cultured viruses have diurnal infection rhythms which are critical for understanding how light–dark cycles shape the interaction of cyanophages and their hosts in the oceans.