DNA viruses profiling of seawater from Chuuk State, Federated States of Micronesia, 2014

Abstract

To investigate year-round DNA virus dynamics by metagenomic virome profiling of tropical seawater in Chuuk State, Federated States of Micronesia (FSM). The results indicated the presence of highly diverse virus communities. Among all identified marine viruses, 61~79% were bacteriophages. Caudovirales (tailed bacteriophages with the families Myoviridae, Siphoviridae, and Podoviridae) was the dominant order in all samples. Despite the regional nature of the tropics, the environmental properties (temperature, salinity, pH, and chlorophyll-a) of Chuuk State seawater remained unchanged over the four seasons, viral dynamics were dramatically changed in June. Interestingly, the proportion of viruses that infect marine primary producers changed in June; cyanophages decreased and phycodnaviruses increased. The proportion of NCLDV was higher in Chuuk seawater in June than in other seasons, especially poxviruses, iridoviruses, and adenoviruses were significantly increased. Our results allow us to speculate that the main cause of the dramatic viral community change in Chuuk seawater in June was due to changes in cyanophages and phycodnaviruses that infect marine primary producers. The information presented here can serve as a basis for comparative analyses with other marine viral communities, be useful regarding marine life and human health care in Chuuk State.