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Detection of Low Copy Number Integrated Viral DNA Formed by In Vitro Hepatitis B Infection
Published on: November 7, 2018
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G-quadruplexes in the evolution of hepatitis B virus
Václav Brázda1, Michaela Dobrovolná1,2, Natália Bohálová1
1Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic.
Nucleic Acids Research
|July 3, 2023
Summary
Hepatitis B virus (HBV) G-quadruplex-forming sequences (PQS) increased over time, matching human genome PQS frequency. This evolutionary
Area of Science:
- Virology
- Genomics
- Evolutionary Biology
Background:
- Hepatitis B virus (HBV) is a globally significant human pathogen.
- G-quadruplexes (G4) are increasingly recognized as potential therapeutic targets in virology.
- Ancient HBV genomes provide insights into viral evolution over millennia.
Purpose of the Study:
- To investigate the presence and evolution of G-quadruplex-forming sequences (PQS) in both ancient and modern HBV genomes.
- To compare PQS frequency in HBV with that of the human genome.
- To test the hypothesis of evolutionary convergence of PQS frequencies between chronic viruses and their hosts.
Main Methods:
- Bioinformatic analysis of PQS in 232 modern and ancient HBV genomes.
- Utilized G4Hunter algorithm to score and identify PQS.
- Statistical comparison of PQS densities across different HBV genomes and lineages.
Main Results:
- PQS were detected in all analyzed HBV genomes, with an average frequency of 1.69 per kbp.
- The most conserved PQS in the reference genome exhibited the highest G4Hunter score.
- Modern HBV genomes show a higher PQS density (1.9/kb) compared to ancient genomes (1.5/kb), approaching human genome PQS frequency (1.93/kb).
Conclusions:
- HBV's PQS content has increased over evolutionary time, converging with the human genome's PQS frequency.
- This convergence supports the 'genetic camouflage' hypothesis, aiding viral evasion and host machinery exploitation.
- Findings represent the first paleogenomic analysis of G4 propensity in viruses.
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