Study of genetic reassortment between two human rotaviruses.

Eight different human rotavirus strains were adapted to replicate in cell culture. In vitro, rotavirus genetic reassortment has been performed between two virus strains, one with a long pattern of segmented genomic RNAs and the other with a short pattern in the electrophoretic mobility of genomic RNAs. This genetic reassortment was detectable despite the lack of selective markers in the parental strains. Moreover, some of the reassorted virus exhibited mixed RNA patterns containing extra genomic RNAs resembling those found in clinical specimens. These viruses with mixed RNA band patterns could segregate their supplementary segments after successive passages in cell culture. Finally it has been shown that classification of genomic segments in long and short electropherotypes should not only be based on their relative size but also by their ability to reassort with the genetically equivalent segment.