- Camargo, Antonio Pedro;
- Nayfach, Stephen;
- Chen, I-Min A;
- Palaniappan, Krishnaveni;
- Ratner, Anna;
- Chu, Ken;
- Ritter, Stephan J;
- Reddy, TBK;
- Mukherjee, Supratim;
- Schulz, Frederik;
- Call, Lee;
- Neches, Russell Y;
- Woyke, Tanja;
- Ivanova, Natalia N;
- Eloe-Fadrosh, Emiley A;
- Kyrpides, Nikos C;
- Roux, Simon
Viruses are widely recognized as critical members of all microbiomes. Metagenomics enables large-scale exploration of the global virosphere, progressively revealing the extensive genomic diversity of viruses on Earth and highlighting the myriad of ways by which viruses impact biological processes. IMG/VR provides access to the largest collection of viral sequences obtained from (meta)genomes, along with functional annotation and rich metadata. A web interface enables users to efficiently browse and search viruses based on genome features and/or sequence similarity. Here, we present the fourth version of IMG/VR, composed of >15 million virus genomes and genome fragments, a ≈6-fold increase in size compared to the previous version. These clustered into 8.7 million viral operational taxonomic units, including 231 408 with at least one high-quality representative. Viral sequences in IMG/VR are now systematically identified from genomes, metagenomes, and metatranscriptomes using a new detection approach (geNomad), and IMG standard annotation are complemented with genome quality estimation using CheckV, taxonomic classification reflecting the latest taxonomic standards, and microbial host taxonomy prediction. IMG/VR v4 is available at https://img.jgi.doe.gov/vr, and the underlying data are available to download at https://genome.jgi.doe.gov/portal/IMG_VR.