Molecular Evolution of Hepatitis B Virus over 25 Years
- 1 November 2006
- journal article
- research article
- Published by American Society for Microbiology in Journal of Virology
- Vol. 80 (21), 10307-10314
- https://doi.org/10.1128/jvi.00996-06
Abstract
Determining the longitudinal molecular evolution of hepatitis B virus (HBV) is difficult due to HBV's genomic complexity and the need to study paired samples collected over long periods of time. In this study, serial samples were collected from eight hepatitis B virus e antigen-negative asymptomatic carriers of HBV genotype B in 1979 and 2004, thus providing a 25-year period to document the long-term molecular evolution of HBV. The rate, nature, and distribution of mutations that emerged over 25 years were determined by phylogenetic and linear regression analysis of full-length HBV genome sequences. Nucleotide hypervariability was observed within the polymerase and pre-S/S overlap region and within the core gene. The calculated mean number of nucleotide substitutions/site/year (7.9 × 10 −5 ) was slightly higher than published estimates (1.5 × 10 −5 to 5 × 10 −5 ). Nucleotide changes in the quasispecies population did not significantly alter the molecular evolutionary rate, based on linear regression analysis of evolutionary distances among serial clone pre-S region sequences. Therefore, the directly amplified or dominant sequence was sufficient to estimate the putative molecular evolutionary rate for these long-term serial samples. On average, the ratio of synonymous ( d S ) to nonsynonymous ( d N ) substitutions was highest for the polymerase-coding region and lowest for the core-coding region. The low d S / d N ratios observed within the core suggest that selection occurs within this gene region, possibly as an immune evasion strategy. The results of this study suggest that HBV sequence divergence may occur more rapidly than previously estimated, in a host immune phase-dependent manner.This publication has 33 references indexed in Scilit:
- HIV Infection and Antiretroviral Therapy: Effect on Hepatitis C Virus Quasispecies VariabilityThe Journal of Infectious Diseases, 2006
- Recombination in the Genesis and Evolution of Hepatitis B Virus GenotypesJournal of Virology, 2005
- Molecular Virology and the Development of Resistant Mutants: Implications for TherapySeminars in Liver Disease, 2005
- Doctor to patient transmission of hepatitis B virus: implications of HBV DNA levels and potential new solutionsAntiviral Research, 2003
- Sensitive Detection of HBsAg Mutants by a Gap Ligase Chain Reaction AssayJournal of Clinical Microbiology, 2002
- High degree of conservation in the hepatitis B virus core gene during the immune tolerant phase in perinatally acquired chronic hepatitis B virus infectionJournal of Hepatology, 1997
- Transmission of Hepatitis B to Patients from Four Infected Surgeons without Hepatitis B e antigenThe New England Journal of Medicine, 1997
- High rate of mutations in the hepatitis B core gene during the immune clearance phase of chronic hepatitis B virus infectionHepatology, 1996
- Reduction of synonymous substitutions in the core protein gene of hepatitis C virusJournal of Molecular Evolution, 1994
- Hepatitis virus infection in an isolated canadian inuit (Eskimo) populationJournal of Medical Virology, 1982