Giant viruses-big surprises

Nadav Brandes, Michal Linial*

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

51 Scopus citations


Viruses are the most prevalent infectious agents, populating almost every ecosystem on earth. Most viruses carry only a handful of genes supporting their replication and the production of capsids. It came as a great surprise in 2003 when the first giant virus was discovered and found to have a >1 Mbp genome encoding almost a thousand proteins. Following this first discovery, dozens of giant virus strains across several viral families have been reported. Here, we provide an updated quantitative and qualitative view on giant viruses and elaborate on their shared and variable features. We review the complexity of giant viral proteomes, which include functions traditionally associated only with cellular organisms. These unprecedented functions include components of the translation machinery, DNA maintenance, and metabolic enzymes. We discuss the possible underlying evolutionary processes and mechanisms that might have shaped the diversity of giant viruses and their genomes, highlighting their remarkable capacity to hijack genes and genomic sequences from their hosts and environments. This leads us to examine prominent theories regarding the origin of giant viruses. Finally, we present the emerging ecological view of giant viruses, found across widespread habitats and ecological systems, with respect to the environment and human health.

Original languageAmerican English
Article number404
Issue number5
StatePublished - May 2019

Bibliographical note

Publisher Copyright:
© 2019 by the authors. Licensee MDPI, Basel, Switzerland.


  • Amebae viruses
  • Dsdna viruses
  • Mimivirus
  • Pandoravirus
  • Protein domains
  • Translation machinery
  • Viral evolution


Dive into the research topics of 'Giant viruses-big surprises'. Together they form a unique fingerprint.

Cite this