1 Reconciliation of Rotavirus Temperature-Sensitive Mutant Collections and Assignment of Reassortment Groups D, J, and K to Genome Segments

ABSTRACT (245 words) Four rotavirus SA11 temperature-sensitive (ts) mutants and seven rotavirus RRV ts mutants, isolated at the National Institutes of Health (NIH) and not genetically characterized, were assigned to reassortment groups by pairwise crosses with the SA11 mutant group prototypes isolated and characterized at Baylor College of Medicine (BCM). Among the NIH mutants, three of the RRV mutants and all four SA11 mutants contained mutations in single reassortment groups and four RRV mutants contained mutations in multiple groups. One NIH mutant (RRVtsK[2]) identified the previously undefined 11th reassortment group (K) expected for rotavirus. Three NIH single mutant RRV viruses, RRVtsD(7), RRVtsJ(5) and RRVtsK(2), were in reassortment groups not previously mapped to genome segments. These mutants were mapped using classical genetic methods, including backcrosses to demonstrate reversion or suppression in reassortants with incongruent genotype and temperature phenotype. Once located to specific genome segments by genetic means, the mutations responsible for ts phenotype were identified by sequencing. The reassortment group K mutant RRVtsK(2) maps to genome segment 9 and has a Thr280Ileu mutation in the capsid surface glycoprotein VP7