Q — Quasispecies
The quasispecies concept describes the dynamic population structure of RNA viruses, which exist as diverse mutant swarms due to error-prone replication. Rather than a single genome sequence, a cloud of related variants evolves under selective pressures.
This diversity facilitates immune escape, antiviral resistance, and adaptation to new hosts. HIV, HCV, and influenza exemplify quasispecies dynamics. Importantly, the collective ‘fitness’ of a quasispecies is greater than that of the individual members, meaning that the population evolves as a group. However, higher mutation rates can also lead to error catastrophe if polymerase fidelity is excessively reduced. Some antivirals exploit this principle.
Quasispecies theory has reshaped understanding of viral evolution, emphasizing population-level rather than single-genome dynamics in pathogenesis and treatment response.
The quasispecies concept describes the dynamic population structure of RNA viruses, which exist as diverse mutant swarms due to error-prone replication. Rather than a single genome sequence, a cloud of related variants evolves under selective pressures.
This diversity facilitates immune escape, antiviral resistance, and adaptation to new hosts. HIV, HCV, and influenza exemplify quasispecies dynamics. Importantly, the collective ‘fitness’ of a quasispecies is greater than that of the individual members, meaning that the population evolves as a group. However, higher mutation rates can also lead to error catastrophe if polymerase fidelity is excessively reduced. Some antivirals exploit this principle.
Quasispecies theory has reshaped understanding of viral evolution, emphasizing population-level rather than single-genome dynamics in pathogenesis and treatment response.