NONRANDOM SELECTION OF GENE SEGMENT-3 AND RANDOM SELECTION OF GENE SEGMENT-5 OBSERVED IN REASSORTANTS GENERATED IN-VITRO BETWEEN ROTAVIRUS SA11 AND RRV

A total of 154 clones of reassortants between rotavirus RRV and SA11 w ere isolated in vitro in order to compare the selection modes of each RNA segment in reassortant formation with those in the in vivo experim ent (carried out by Gombold and Ramig) using the same parent strains i n which the occurrence of non-random selection of gene segments 3 and 5 was observed. In reassortants isolated from a cross RRVxSA11-L2 (66 isolates) and a cross RRVxSA11-S1 (88 isolates), 36 and 57 different g enotypes were identified, respectively. Segregation rates of SA11 RNA segments 1, 5, 8, 9 and 11 were significantly different as compared wi th those previously reported in the in vivo experiment. While RNA segm ent 3 was preferentially selected from an SA11 parent, the segregation rate of SA11 gene 5 was relatively low in vitro. Thus, the selection mode of rotavirus RNA segments was found to be different between in vi vo and in vitro reassortments.