Analysis of seasonal changes in marine virus metagenomes near Jeju Island, Korea

Abstract

Jeju Island is the largest and most economically important island in South Korea. We examined the marine viral metagenome in the sea adjacent to Jeju Island in 4 different seasons of 2014. The DNA libraries derived from March, June, September, and December samples were sequenced using Illumina HiSeq 2000. We obtained 212,402 contigs in March, 186,542 in June, 235,441 in September, and 224,513 in December. Among the 4 seasonal metagenomes, bacteriophages were dominant in all samples. For example, Bacillus phage G was dominant in March and June, and Pelagibacter phage HTVC 008M was dominant in September and December. In addition, viruses that infect algae were most abundant in December. Marine viruses that infect fish and/or other vertebrates appeared in all 4 seasons. Interestingly, functional characterization by MG-RAST indicated that cell wall and capsule related metabolism groups were predominant in March and June, and virulence, disease, and defense related metabolism were predominant in September and December. In summary, our results provide evidence of seasonal changes of the marine viral community in the sea adjacent to Jeju Island. These data provide a valuable foundation for future studies of marine vital communities, and the approach used here may be useful for identification of emerging marine viral pathogens.