Viromes

A virome is the collection of viruses present in a given environment or within a host. In virology and ecology, viromics uses high-throughput sequencing and computational analysis to characterize viral diversity, abundance, and potential functions.

Viromes include DNA and RNA viruses, encompassing bacteriophages, eukaryotic viruses, and archaeal viruses. In most environments, bacteriophages are the most abundant component, whereas host-associated viromes contribute substantial viral diversity relevant to health and disease.

Methods involve collecting samples, isolating virus-like particles, extracting nucleic acids, sequencing, and bioinformatic analysis. Much of environmental viral diversity is novel and lacks reference genomes, creating viral dark matter. Tools such as VirSorter and VirFinder help detect viral signals, but annotation remains challenging.

Ecologically, viromes shape microbial communities through infection and lysis, influence gene transfer by transduction, and affect biogeochemical cycles via the viral shunt. Some viruses carry auxiliary metabolic genes that can alter host metabolism and ecosystem function.

In humans, the virome includes gut, oral, skin, and respiratory viruses, reflecting diet, immunity, and antimicrobial exposure. Environmental viromes are studied in oceans, soils, freshwater, and built environments, informing models of carbon cycling, disease emergence, and ecosystem resilience.

Taxonomy follows ICTV standards, but many environmental viruses remain unclassified. The discovery of giant viruses and virophages has broadened notions of viral diversity. Advances in long-read sequencing and integrated multi-omics are expanding virome research.