Related Experiment Video
Updated: Jun 17, 2026
11:14
Detection of Low Copy Number Integrated Viral DNA Formed by In Vitro Hepatitis B Infection
Published on: November 7, 2018
Hepatitis B virus: origin and evolution
S M Jazayeri1, S M Alavian, W F Carman
1Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. jazayerism@tums.ac.ir
Journal of Viral Hepatitis
|December 17, 2009
Summary
Hepatitis B virus (HBV) evolution involves complex molecular variants and quasispecies. Understanding HBV origin and genotype correlations aids in tracing human migration patterns and historical epidemiology.
Area of Science:
- Virology
- Molecular Biology
- Epidemiology
Background:
- Hepatitis B virus (HBV) pathogenesis is intricate, with molecular variants contributing to disease complexity.
- HBV replication generates heterogeneous quasispecies due to error-prone production within infected hosts.
Purpose of the Study:
- To review controversies surrounding the origin of Hepatitis B virus.
- To explore factors influencing HBV quasispecies diversity.
- To examine the correlation between HBV genotypes, human history, and migration patterns.
Main Methods:
- Literature review synthesizing existing research on HBV.
- Genetic analysis of HBV strains to infer evolutionary pathways.
- Epidemiological data interpretation to understand historical spread.
Main Results:
- HBV quasispecies are heterogeneous, complicating direct evolutionary studies.
- Indirect inference of HBV evolution relies on epidemiology and genetic analysis.
- Evidence suggests correlations between HBV genotypes and human historical movements.
Conclusions:
- The origin and evolution of HBV are complex and require further investigation.
- Understanding HBV quasispecies dynamics is crucial for comprehending viral evolution.
- HBV genotype distribution offers insights into past human migrations and population dynamics.
Related Concept Videos
01:25Hepatitis
Hepatitis is an inflammatory condition of the liver most commonly caused by hepatotropic viruses (A–E), though non-infectious causes such as alcohol and drugs also exist.Hepatitis AHepatitis A virus (HAV) is a non-enveloped RNA virus of the Picornaviridae family. It is primarily transmitted via the fecal-oral route, typically through ingestion of contaminated food or water. After ingestion, HAV enters the bloodstream through the oropharynx or intestinal epithelium and reaches the liver. The...
01:28Viral Hepatitis I: Introduction
Viral hepatitis is an inflammatory condition of the liver caused by infection with hepatotropic viruses, most commonly hepatitis A, B, C, D, and E. Despite variations in structure and transmission, all viruses mentioned infect hepatocytes and provoke immune responses that can hinder liver function. Additionally, some non-hepatotropic viruses can also lead to hepatic inflammation.Hepatitis A VirusHepatitis A virus (HAV) is transmitted through the fecal–oral route, typically by ingestion of food...
00:36Viral Mutations
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material for adaptive...
02:33Retroviruses
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
01:29Viruses with RNA Genomes
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
01:10Retrovirus Life Cycles
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to...