The evolution of multicompartmental genomes in viruses

Area of Science:

• Virology
• Evolutionary Biology
• Genetics

Background:

• Many viruses possess genomes divided into multiple nucleic acid molecules, each enclosed in its own protein coat.
• This genomic compartmentalization is observed in various viral families, particularly those infecting plants.

Purpose of the Study:

• To construct a simple evolutionary model explaining the phenomenon of viral genome division.
• To explore the potential drivers behind multicompartmental viruses, focusing on plant viruses and RNA viruses.

Main Methods:

• Development of a basic evolutionary model to analyze genome division in viruses.
• Consideration of a "selfish DNA" perspective, where genome division may not serve an adaptive function for the virus itself.

Main Results:

• The model suggests that high transmission multiplicities in plant viruses may favor genome division.
• Low replication fidelity of RNA viruses is proposed as another potential factor, with an alternative explanation also presented.
• The analysis contrasts the proposed model with previous explanations for viral genome compartmentalization.

Conclusions:

• Genome division in viruses does not necessarily require an adaptive function for the virus.
• The "selfish DNA" viewpoint offers a parsimonious explanation for multicompartmental viruses.
• The developed theory yields testable predictions regarding the characteristics of multicompartmental viruses.