Cheating leads to the evolution of multipartite viruses

Area of Science:

• Virology
• Evolutionary Biology
• Genomics

Background:

• Multipartite viruses possess genomes split into multiple segments, each enclosed in a separate capsid.
• Replication necessitates the co-occurrence of all genomic segments within a single host, posing a significant challenge for these viruses.

Purpose of the Study:

• To investigate the evolutionary drivers behind the commonality of multipartitism in viruses.
• To propose and test a novel hypothesis for the evolution of multipartite and segmented viruses.

Main Methods:

• Theoretical modeling was employed to explore evolutionary dynamics.
• The study focused on the role of 'cheating' in viral genome organization.

Main Results:

• Selection for cheating, where viruses benefit from shared gene products without contributing, can drive multipartite evolution.
• This cheating hypothesis explains multipartitism under realistic conditions, without requiring high coinfection rates or group benefits.
• The model is consistent with observed patterns of cheating and multipartitism across diverse viruses.

Conclusions:

• Evolutionary conflict, specifically cheating, provides a robust explanation for the prevalence of multipartite and segmented viruses.
• This mechanism offers a more realistic and broadly applicable framework compared to previous hypotheses.
• The findings highlight how evolutionary conflict shapes genome organization not only in viruses but potentially in other biological systems.