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Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses
Published on: December 29, 2015
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Recombination in large RNA viruses: Coronaviruses
1From the Howard Hughes Medical Institute, Department of Molecular Microbiology and Immunology, University of Southern California School of Medicine, Los Angeles, CA, 90033-1054, USA.
Seminars in Virology
|April 15, 2024
Summary
Coronaviruses frequently undergo RNA recombination, a process vital for their evolution and genomic diversity. This high-frequency recombination, occurring between viral genomes and defective-interfering RNAs, contributes to coronavirus adaptability.
Area of Science:
- Virology
- Molecular Biology
- Genetics
Background:
- Coronaviruses possess large RNA genomes.
- RNA recombination occurs at a high frequency (nearly 25%) in coronaviruses.
- Recombination has been observed between viral genomes and between defective-interfering (DI) RNAs and viral RNA.
Purpose of the Study:
- To explore the role of recombination in coronavirus evolution and genomic diversity.
- To investigate the relationship between coronavirus mRNA transcription mechanisms and recombination frequency.
- To understand recombination as a tool for viral genomic RNA mutagenesis.
Main Methods:
- Analysis of coronavirus genomic structure.
- Investigation of RNA transcription mechanisms, including discontinuous RNA synthesis.
- Assessment of viral polymerase processivity.
Main Results:
- Coronaviruses exhibit a high frequency of genome-wide recombination (nearly 25%).
- Recombination occurs between viral genomes and between DI RNAs and viral RNA.
- The mRNA transcription mechanism, involving discontinuous RNA synthesis, suggests a nonprocessive viral polymerase, potentially facilitating recombination.
- Recombination serves as a mechanism for viral genomic RNA mutagenesis.
Conclusions:
- High-frequency recombination is a key evolutionary mechanism for coronaviruses, driving genomic diversity.
- The discontinuous RNA synthesis characteristic of coronavirus transcription likely contributes to its high recombination rate.
- Recombination is a significant factor in the mutagenesis and adaptation of coronavirus genomes.
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