Journal
MICROBIOLOGY AND MOLECULAR BIOLOGY REVIEWS
Volume 85, Issue 3, Pages -Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/MMBR.00053-21
Keywords
virus classification; virus evolution; virus realms; virus taxonomy
Categories
Funding
- Intramural Research Program of the National Institutes of Health of the USA (National Library of Medicine)
- l'Agence Nationale de la Recherche [ANR-20-CE20-0009]
- Emergence(s) project MEMREMA from Ville de Paris
- Russian Science Foundation [20-14-00178]
- Agence Nationale de la Recherche (ANR) [ANR-20-CE20-0009] Funding Source: Agence Nationale de la Recherche (ANR)
- Russian Science Foundation [20-14-00178] Funding Source: Russian Science Foundation
Ask authors/readers for more resources
David Baltimore's classification of viruses based on genome expression routes has been fundamental in virology for the past fifty years, providing a conceptual framework for understanding virus diversity. Recent studies have focused on the global ecology and biology of viruses within the context of the Baltimore classes, with an exploration of potential extensions to the original scheme.
Fifty years ago, David Baltimore published a brief conceptual paper delineating the classification of viruses by the routes of genome expression. The six Baltimore classes of viruses, with a subsequently added 7th class, became the conceptual framework for the development of virology during the next five decades. During this time, it became clear that the Baltimore classes, with relatively minor additions, indeed cover the diversity of virus genome expression schemes that also define the replication cycles. Here, we examine the status of the Baltimore classes 50 years after their advent and explore their links with the global ecology and biology of the respective viruses. We discuss an extension of the Baltimore scheme and why many logically admissible expression-replication schemes do not appear to be realized in nature. Recent phylogenomic analyses allow tracing the complex connections between the Baltimore classes and the monophyletic realms of viruses. The five classes of RNA viruses and reverse-transcribing viruses share an origin, whereas both the single-stranded DNA viruses and double-stranded DNA (dsDNA) viruses evolved on multiple independent occasions. Most of the Baltimore classes of viruses probably emerged during the earliest era of life evolution, at the stage of the primordial pool of diverse replicators, and before the advent of modern-like cells with large dsDNA genomes. The Baltimore classes remain an integral part of the conceptual foundation of biology, providing the essential structure for the logical space of information transfer processes, which is nontrivially connected with the routes of evolution of viruses and other replicators.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available