title: Hepatitis B virus of genotype B with or without recombination with genotype C over the precore region plus the core gene.
abstract: The entire nucleotide sequences of 70 hepatitis B virus (HBV) isolates of genotype B (HBV/B), including 38 newly determined and 32 retrieved from the international DNA database (DDBJ/EMBL/GenBank), were compared phylogenetically. Two subgroups of HBV/B were identified based on sequence divergence in the precore region plus the core gene, one with the recombination with genotype C and the other without it. The analysis over the entire genome of HBV/B by the SimPlot program located the recombination with genotype C in the precore region plus the core gene spanning nucleotide positions from 1740 to 1838 to 2443 to 2485. Within this genomic area, HBV/B strains with the recombination had higher nucleotide and amino acid homology to genotype C than those without the recombination (96.9 versus 91.1% in nucleotides and 97.0 versus 92.9% in amino acids). There were 29 HBV/B strains without the recombination, and they were all recovered from carriers in Japan. The remaining 41 HBV/B isolates having the recombination with genotype C were from carriers in China (12 strains), Hong Kong (3 strains), Indonesia (4 strains), Japan (3 strains), Taiwan (4 strains), Thailand (3 strains), and Vietnam (12 strains). Due to the frequency of the distribution of HBV/B without the recombination (29 of 32 isolates, or 91%) and the fact that it was exclusive to Japan, it was provisionally classified into the Bj (j standing for Japan) subgroup, and HBV/B with the recombination was classified into the Ba (a for Asia) subgroup. Virological differences between HBV/Bj and HBV/Ba may be reflected in the severity of clinical disease in the patients infected with HBV of genotype B, which seems to be under strong geographic influences in Asia.
authors.affiliation: Department of Internal Medicine and Molecular Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Fuminaka
authors.initials: F
authors.lastname: Sugauchi
authors.forename: Etsuro
authors.initials: E
authors.lastname: Orito
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ichida
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakugawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kakumu
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ishida
authors.forename: Anuchit
authors.initials: A
authors.lastname: Chutaputti
authors.forename: Ching-Ling
authors.initials: CL
authors.lastname: Lai
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Ueda
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Miyakawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
mesh_terms: D001483:Base Sequence; D005838:Genotype; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011498:Protein Precursors / Q000235:genetics*; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D014758:Viral Core Proteins / Q000235:genetics*
chemical_list: D011498:Protein Precursors; D014758:Viral Core Proteins