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Updated: Oct 29, 2025
18:10
Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency
Published on: June 16, 2011
29.8K
Why are viral genomes so fragile? The bottleneck hypothesis
Nono S C Merleau1, Sophie Pénisson2,3, Philip J Gerrish4
1Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.
Plos Computational Biology
|July 8, 2021
Summary
RNA viral genomes are fragile as an evolutionary strategy to survive population bottlenecks. This genetic fragility helps viruses manage mutations, increasing survival rates and potentially leading to higher attack rates in certain conditions.
Area of Science:
- Virology
- Evolutionary Biology
- Epidemiology
Background:
- RNA viruses accumulate mutations during replication.
- Most viral mutations are detrimental or lethal, posing a paradox for genome stability.
- Viral populations frequently experience population bottlenecks during their life cycles.
Purpose of the Study:
- To investigate the hypothesis that genetic fragility in RNA viruses is an evolutionary adaptation.
- To understand the role of population bottlenecks in shaping viral genome architecture.
- To determine the epidemiological consequences of viral genetic fragility.
Main Methods:
- Theoretical modeling of within-host viral populations using multi-type branching processes.
- Numerical simulations to analyze the impact of fragility on Muller's ratchet.
- Integration into a susceptible-exposed-infectious-recovered (SEIR) epidemiological model.
Main Results:
- Genetic fragility reduces the rate of Muller's ratchet, preserving genome integrity.
- Increased survival probability through multiple population bottlenecks was observed.
- Fragile viral strains can exhibit higher attack rates than robust strains, especially at low infectivity and high mutation rates.
Conclusions:
- Viral genetic fragility is partly an evolutionary response to population bottlenecks.
- Demographic events like transmission bottlenecks are crucial in shaping viral genetic makeup.
- Understanding viral fragility is key to predicting pathogen evolution and spread.
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