Host Competitive Asymmetries Accelerate Viral Evolution in a Microbe-Virus Coevolutionary System.
Armun Liaghat1,2, Martin Guillemet3,4, Rachel Whitaker5,6
1Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, USA.
Ecology Letters
|June 19, 2025
Summary
Microbial host-virus coevolution shows that host competitive traits drive viral diversity and adaptation. Greater host competition prolongs viral persistence and enhances viral evolution, impacting long-term dynamics.
Area of Science:
- Microbial ecology
- Evolutionary biology
- Virology
Background:
- Microbe-virus interactions involve reciprocal evolution of defences and counter-defences.
- Coevolutionary dynamics are often shaped by negative frequency-dependent selection, promoting diversification.
- Microbial competitive traits can impose directional selection, potentially opposing diversification.
Purpose of the Study:
- To investigate the combined effects of host resistance and competitive traits on viral evolution and persistence.
- To clarify the impact of co-occurring host trait types on microbe-virus coevolutionary dynamics.
- To reconcile experimental findings with computational models of microbial coevolution.
Main Methods:
- Utilized a CRISPR-mediated experimental system to study microbe-virus coevolution.
- Developed a stochastic model incorporating host competitive asymmetries (variation in intrinsic growth rates).
- Analyzed viral evolution, adaptation, and persistence under varying host trait conditions.
Main Results:
- Competitively advantaged host clades were identified as the primary source of immune diversity.
- Increased host competitive asymmetry extended viral extinction times.
- Greater host asymmetry accelerated local viral adaptation and augmented long-term adaptation.
Conclusions:
- Host competitive traits play a crucial role in shaping viral evolution and persistence alongside defence mechanisms.
- Competitive asymmetries can significantly alter the trajectory of micro- and viral coevolution.
- Findings provide insights into the long-term dynamics of microbial host-virus systems.
Related Concept Videos
00:36Viral Mutations
33.1K
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
33.1K
00:57Viral Recombination
23.8K
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.
23.8K
01:26Size and Structure of Viral Genomes
170
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
170
01:20Viral Replication: Lytic Cycle
299
Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
299
01:10Retrovirus Life Cycles
47.0K
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
47.0K
01:30Lytic Cycle of Bacteriophages
72.3K
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...
72.3K