The kinetoplastid-infecting Bodo saltans virus (BsV), a window into the most abundant giant viruses in the sea

• Published in: eLife Vol. 7
• Main Authors: Deeg, Christoph M, Chow, Cheryl-Emiliane T, Suttle, Curtis A
• Format: Journal Article
• Language: English
• Published: England eLife Sciences Publications Ltd 27.03.2018; eLife Sciences Publications, Ltd
• Subjects: Acanthamoeba; Acanthamoeba polyphaga; Aquatic ecosystems; Bodo saltans; Bodo saltans virus; Deoxyribonucleic acid; DNA; Endonuclease; Evolution, Molecular; Flow cytometry; Gene duplication; Genes; Genes, Viral; Genome, Viral; Genomes; Giant Viruses; Giant Viruses - classification; Giant Viruses - genetics; Giant Viruses - isolation & purification; Gigantism; Homing endonuclease; Host-Pathogen Interactions; Infections; Introns; Kinetoplastida - virology; Metagenomics; Microbiology and Infectious Disease; Mimiviridae - classification; Mimiviridae - genetics; Mimiviridae - isolation & purification; NCLDV; Oceans; Oceans and Seas; Open Reading Frames; Phylogenetics; Seawater - virology; Software; Splicing; Trees; Viruses; Canada; NCLDV; evolutionary biology; Giant Viruses; Bodo saltans virus; infectious disease; microbiology; genomics; Bodo saltans
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.33014

Giant viruses are ecologically important players in aquatic ecosystems that have challenged concepts of what constitutes a virus. Herein, we present the giant Bodo saltans virus (BsV), the first characterized representative of the most abundant group of giant viruses in ocean metagenomes, and the first isolate of a klosneuvirus, a subgroup of the proposed from metagenomic data. BsV infects an ecologically important microzooplankton, the kinetoplastid . Its 1.39 Mb genome encodes 1227 predicted ORFs, including a complex replication machinery. Yet, much of its translational apparatus has been lost, including all tRNAs. Essential genes are invaded by homing endonuclease-encoding self-splicing introns that may defend against competing viruses. Putative anti-host factors show extensive gene duplication via a genomic accordion indicating an ongoing evolutionary arms race and highlighting the rapid evolution and genomic plasticity that has led to genome gigantism and the enigma that is giant viruses.