title: Molecular characterization of serotype G2 and G3 human rotavirus strains that have an apparently identical electropherotype of the short RNA pattern.
abstract: The literature is conflicting whether or not rotavirus strains with different G serotype have an identical electropherotype. This is a contentious but an important issue because large parts of molecular epidemiological studies of rotaviruses have been based on the conception that a single strain of rotavirus can be defined by a single electropherotype. Here, we examined in detail by reverse-transcription PCR genotyping, electropherotyping, sequencing, and genogrouping using RNA--RNA hybridization three human rotavirus strains isolated in India that had apparently identical electropherotypes although one strain was typed as P[4], G3 while the other two typed as P[4], G2. These three strains showed an identical electropherotype on 7.5% and 12.5% polyacrylamide gels, but co-electrophoresis on a 10% gel demonstrated that segment 8 of the P[4], G3 strain migrated more slowly than the cognate segment of the P[4], G2 strains. Genogrouping assay and nucleotide sequencing provided evidence for the hypothesis that the P[4], G3 stain was an intergenogroup reassortant in which a P[4], G2 strain of the DS-1 genogroup had acquired the VP7 gene from an yet-unidentified concurrently circulating G3 strain. While electropherotyping remains a valuable asset for molecular epidemiology of rotaviruses, this study underscores the importance of co-electrophoresis under different electrophoretic conditions when pinpointing subtle differences.
authors.affiliation: Department of Microbiology, Akita University School of Medicine, Akita, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakagomi
authors.forename: J R
authors.initials: JR
authors.lastname: Gentsch
authors.forename: B K
authors.initials: BK
authors.lastname: Das
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: M K
authors.initials: MK
authors.lastname: Bhan
authors.forename: R I
authors.initials: RI
authors.lastname: Glass
authors.forename: O
authors.initials: O
authors.lastname: Nakagomi
mesh_terms: D000956:Antigens, Viral; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000032:analysis*; D012401:Rotavirus / Q000145:classification* / Q000235:genetics*; D012703:Serotyping
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; D012367:RNA, Viral; C050779:VP7 protein, Rotavirus