Mamavirus

Mamavirus

The Mamavirus is a large virus belonging to the family Mimiviridae. It is closely related to the Mimivirus, which was the first giant virus discovered. Mamavirus is notable for its large size and complex genome, which challenges traditional definitions of viruses and blurs the line between viruses and cellular life.

Discovery

Mamavirus was discovered in 2008 in a cooling tower in Paris, France. It was isolated from an Acanthamoeba polyphaga amoeba, similar to its relative, the Mimivirus. The discovery of Mamavirus added to the growing list of giant viruses, which are characterized by their large capsid size and extensive genetic material.

Structure

Mamavirus has a large icosahedral capsid with a diameter of approximately 500 nanometers, making it one of the largest known viruses. The capsid is composed of a protein shell that encases the viral genome. The genome of Mamavirus is a double-stranded DNA molecule, which is significantly larger than that of most other viruses.

Genome

The genome of Mamavirus is approximately 1.2 million base pairs in length, containing over 1,000 genes. This extensive genetic repertoire includes genes that are typically found in cellular organisms, such as those involved in DNA replication, transcription, and translation. The presence of these genes suggests that Mamavirus may have a more complex life cycle than smaller viruses.

Life Cycle

Mamavirus infects amoebae, specifically Acanthamoeba polyphaga, by entering the host cell and hijacking its machinery to replicate its genome and produce new viral particles. The replication cycle of Mamavirus is similar to that of other giant viruses, involving the formation of a viral factory within the host cell where viral replication and assembly occur.

Sputnik Virophage

One of the most intriguing aspects of Mamavirus is its association with the Sputnik virophage. Sputnik is a small virus that can infect and parasitize Mamavirus, reducing its ability to replicate. This interaction represents a unique form of viral parasitism and has implications for understanding virus-virus interactions and the evolution of viruses.

Significance

The discovery of Mamavirus and other giant viruses has significant implications for the study of virology and the origin of life. These viruses challenge the traditional view of viruses as simple entities and suggest that they may have played a role in the evolution of complex life forms. The study of Mamavirus also provides insights into the diversity and complexity of the viral world.

Also see

• Mimivirus
• Giant virus
• Virophage
• Acanthamoeba
• Virus evolution