Related Experiment Video
Updated: Jun 21, 2026
09:27
A Rapid Strategy for the Isolation of New Faustoviruses from Environmental Samples Using Vermamoeba vermiformis
Published on: June 4, 2016
Mimivirus and its virophage.
Jean-Michel Claverie1, Chantal Abergel
1Structural and Genomic Information Laboratory, CNRS-UPR 2589, IFR-88, Aix-Marseille University, Parc Scientifique de Luminy, Case 934, FR-13288 Marseille, France. jean-michel.claverie@igs.cnrs-mrs.fr
Annual Review of Genetics
|August 6, 2009
Summary
Mimivirus, a large DNA virus, challenges our understanding of viral complexity and evolution. Its unique features, including a large genome and novel protein functions, fuel scientific debate on viral origins and the emergence of eukaryotic cells.
Area of Science:
- Virology
- Microbiology
- Evolutionary Biology
Background:
- Mimivirus, a large DNA virus, infects Acanthamoeba and belongs to the Mimiviridae family.
- Its large particle size and complex genome initially led to its misclassification as a bacterium.
- Mimivirus discovery expanded the known diversity of nucleocytoplasmic large DNA viruses.
Purpose of the Study:
- To investigate the unique characteristics of Mimivirus.
- To explore the implications of Mimivirus's genome and protein repertoire for viral evolution.
- To understand the role of Mimivirus and its associated virophage in cellular origins.
Main Methods:
- Genome sequencing of Mimivirus.
- Bioinformatic analysis of viral genes and encoded proteins.
- Isolation and characterization of associated satellite viruses (virophages).
Main Results:
- Mimivirus possesses a 1.2-Mb genome encoding over 900 proteins.
- The genome includes genes for functions previously unseen in viruses, such as aminoacyl-tRNA synthetases.
- A novel satellite virus, virophage, was discovered associated with Mimivirus, highlighting its unique biological context.
Conclusions:
- Mimivirus's complexity revives debates on the origin of DNA viruses and the emergence of the eukaryotic nucleus.
- The discovery of virophages underscores Mimivirus's unique position and complexity within the viral world.
- Ongoing post-genomic studies aim to elucidate the physiology of this exceptionally complex virus.
Related Concept Videos
01:23Bacteriophages of the Human Virome
Bacteriophages are found throughout the human body. They may even outnumber eukaryotic viruses, forming an important and dynamic component of the human virome. Indeed, phages represent the most abundant viral entities, with densities in the gut reaching up to 10⁹ particles per gram of fecal matter, and many belonging to orders such as Caudovirales and Microviridae, while a substantial proportion remains unclassified as viral “dark matter.”Lysogeny and Genetic ExchangeIn the gut, bacteriophages...
01:26Human Virome
The human body harbors a vast and diverse viral community known as the human virome. The virome includes bacteriophages that infect bacteria, and eukaryotic viruses that infect human cells. Transient dietary and environmental viruses also contribute to this dynamic ecosystem. Estimates suggest the human body may contain on the order of 10¹³ viral particles, though abundance varies widely by body site and detection method.Comprehensive characterization of the virome has become possible only with...
01:26DNA Bacteriophages
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
01:30Lytic Cycle of Bacteriophages
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...
01:29Viruses with RNA Genomes
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
01:25Inhibitors Of Virion Release
Viral replication and dissemination rely on efficient mechanisms for host cell entry, genome replication, assembly, and release. Influenza viruses, such as types A and B, are negative-sense single-stranded RNA viruses with a segmented genome, that depend on two critical surface glycoproteins to carry out these processes: hemagglutinin (HA) and neuraminidase (NA). HA initiates infection by binding to sialic acid residues on the surface of host epithelial cells, facilitating receptor-mediated...