Identification of rotavirus genogroups by RNA-RNA hybridization.

The genetic relatedness of various human rotavirus strains was examined by RNA-RNA hybridization in which 32P-labelled single stranded RNAs produced by in vitro transcription from viral RNAs were used as probes. Denatured genomic double stranded RNAs were hybridized to the probes under highly stringent conditions and the resulting hybrids were fractionated by polyacrylamide gel electrophoresis. Based on the hybridization patterns obtained with probes made from prototype strains Wa (subgroup II, long RNA electropherotype), DS-1 (subgroup I, short RNA electropherotype) and AU-1 (subgroup I, long RNA electropherotype), we have observed that human rotaviruses fall into three distinct gene groups which we have termed 'genogroups'. Identification of genogroups among rotavirus isolates will prove to be a valuable asset for the analysis of naturally occurring reassortants, to trace interspecies transmission of animal rotaviruses to man or vice versa and to identify rotaviruses from environmental sources with regard to their original host species. Furthermore, such an approach will contribute to our understanding of the evolution of rotavirus genes.