Assembly Free Viral Genomes from Station ALOHA. marine plankton metagenome

We developed an assembly-free, single-molecule nanopore sequencing approach enabling direct recovery of high-quality viral genome sequences from environmental samples. Applied to samples from Station ALOHA in the North Pacific Subtropical Gyre, the method yielded full-length double-stranded DNA virus genome sequences and revealed viruses not fully recovered using short read assembly approaches in the same samples. Additionally, novel virus-like DNA sequences were discovered, whose structures, gene contents and concatemer lengths suggested they represent phage-inducible chromosomal islands packaged in discrete concatemeric lengths within phage particles.