Microbial predator found in the ocean

Double-stranded DNA (dsDNA) viruses comprise both tailed and non-tailed viruses and are thought to be the most abundant viruses on Earth. Tailed viruses of the Caudovirales dominate sequence and culture collections, whereas non-tailed dsDNA viruses often dominate ocean samples but remain largely uncharacterized. Martin Polz and colleagues describe a family of diverse marine non-tailed viruses, called the Autolykiviridae. Through metagenomics and phylogenetic analyses, the team show that Autolykiviridae represent an ancient lineage of double jelly roll capsid viruses. They also show that these viruses are abundant in the ocean, where they prey on marine bacteria and archaea. This finding was facilitated by updated methods for environmental viral discovery, and represents an important step forwards in our understanding of environmental bacteria–virus interactions.