title: Characterization and genetic analysis of alternatively spliced transcripts of hepatitis B virus in infected human liver tissues and transfected HepG2 cells.
abstract: The transcriptional map of hepatitis B virus (HBV) has been expanded recently by the discovery of a singly spliced transcript in hepatoma cell lines transfected with cloned viral DNA and a doubly spliced one in naturally infected human liver tissues. By the use of reverse transcription and a subsequent polymerase chain reaction, the two spliced HBV RNAs were shown to be present in both types of cells. As further evidence, an HBV mutant was constructed and found to exclusively express the singly spliced RNA. This mutant was also used to quantitate the two spliced species in transfected HepG2 cells; they were found to be equally abundant, and each represented about 30% of the pregenomic RNA. The HBV mutant could still produce replication-competent HBV virions when transfected into HepG2 cells, indicating that the doubly spliced transcript, just like the singly spliced one, was not essential for HBV replication. However, the two abundant spliced HBV transcripts were detected in most naturally infected human liver tissues, suggesting that they may have biologic functions in vivo.
authors.affiliation: Hepatitis Research Center, Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei.
authors.forename: H L
authors.initials: HL
authors.lastname: Wu
authors.forename: P J
authors.initials: PJ
authors.lastname: Chen
authors.forename: S J
authors.initials: SJ
authors.lastname: Tu
authors.forename: M H
authors.initials: MH
authors.lastname: Lin
authors.forename: M Y
authors.initials: MY
authors.lastname: Lai
authors.forename: D S
authors.initials: DS
authors.lastname: Chen
mesh_terms: D001483:Base Sequence; D004279:DNA, Viral / Q000378:metabolism; D006509:Hepatitis B / Q000235:genetics* / Q000473:pathology; D006515:Hepatitis B virus / Q000235:genetics* / Q000254:growth & development; D006801:Humans; D008099:Liver / Q000382:microbiology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D012367:RNA, Viral / Q000378:metabolism*; D012194:RNA-Directed DNA Polymerase; D014162:Transfection; D014407:Tumor Cells, Cultured; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral; D012194:RNA-Directed DNA Polymerase