Virome

The first comprehensive studies of viromes were by shotgun community sequencing, which is frequently referred to as metagenomics. In the 2000s, the Rohwer lab sequenced viromes from seawater, marine sediments, adult human stool, infant human stool, soil, and blood. This group also performed the first RNA virome with collaborators from the Genomic Institute of Singapore. From these early works, it was concluded that most of the genomic diversity is contained in the global virome and that most of this diversity remains uncharacterized. This view was supported by individual genomic sequencing project, particularly the mycobacterium phage. By the late 2010s advances in sequencing technologies have allowed for a deep probing of viromes. The virome of the human gut in particular has gained increased attention as a result of these advancements. ==Methods of study==

In order to study the virome, virus-like particles are separated from cellular components, usually using a combination of filtration, density centrifugation, and enzymatic treatments to get rid of free nucleic acids. The nucleic acids are then sequenced and analyzed using metagenomic methods. Alternatively, there are recent computational methods that use directly metagenomic assembled sequences to discover viruses. The Global Ocean Viromes (GOV) is a dataset consisting of deep sequencing from over 150 samples collected across the world's oceans in two survey periods by an international team. ==Virus hosts==

Viruses are the most abundant biological entities on Earth, but challenges in detecting, isolating, and classifying unknown viruses have prevented exhaustive surveys of the global virome. Over 5 Tb of metagenomic sequence data were used from 3,042 geographically diverse samples to assess the global distribution, phylogenetic diversity, and host specificity of viruses. -the largest interactive public virus database contained 265,000 metagenomic viral sequences and isolate viruses. This number scaled up to over 760,000 in November 2018 (IMG/VR v.2.0). The IMG/VR systems serve as a starting point for the sequence analysis of viral fragments derived from metagenomic samples. ==Human virome==

The human virome encompasses the diverse viral communities residing in the body. Prior advances in high-throughput sequencing (HTS) revealed insights into their diversity, evolutionary dynamics, and genome integrations. However, due to shallow sequencing in the past, the genetic composition and diversity of tissue-resident viruses remained poorly characterized, hindering understanding of their roles in pathogenesis and viral evolution. In 2024, a study of the virome examined persistent viruses in multiple organs from individuals who died of non-viral causes, revealing that viral sequences were highly conserved within each person, indicating persistence from single dominant strains. Increased viral diversity in two cases suggested that reactivation may influence variability. The study also identified selective pressures from the host and unexpected viral genome integrations, including MCPyV truncations and novel links between herpesvirus 6B and mitochondrial DNA, even in non-cancerous individuals, offering new insights into tissue-resident viruses and their potential health impacts. == See also ==