Related Experiment Video
Updated: Oct 9, 2025

Live Imaging and Quantification of Viral Infection in K18 hACE2 Transgenic Mice Using Reporter-Expressing Recombinant SARS-CoV-2
Published on: November 5, 2021
Evolution of viruses and the emergence of SARS-CoV-2 variants
Giulia Freer1, Michele Lai1, Paola Quaranta1
1Retrovirus Center, Virology Section, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa.
Abstract:
Life implies adaptation. This is one of the fundamental principles that has permitted most living species to survive through ages in an ever-changing environment. Spontaneously occurring events have shaped also virus populations and their fitness. Thanks to their plasticity, viruses have thrived in extremely dissimilar conditions. Unsurprisingly, SARS-CoV-2, the etiological agent of COVID-19, is no exception. Thanks to an unprecedented rate of molecular tracing and sequence scrutiny, the virus was followed in all its changes and shown to evolve in such a way as to possibly determine subsequent waves of infection after the first global and massive outbreak. This review illustrates the major modifications occurred to the virus since its discovery. We describe the potential advantages that these changes conveyed as regards SARS-CoV-2 transmissibility, resistance to host innate and adaptive barriers and molecular diagnosis.
More Related Videos
Related Concept Videos
Viral Mutations
Viral Recombination
Viruses with RNA Genomes
Viruses of Archaea
Size and Structure of Viral Genomes
Retroviruses

