INDEPENDENT SEGREGATION OF THE VP4 AND THE VP7 GENES IN BOVINE ROTAVIRUSES AS CONFIRMED BY VP4 SEQUENCE-ANALYSIS OF G8 AND G10 BOVINE ROTAVIRUS STRAINS

We determined the complete nucleotide sequences of the VP4 genes of fi ve bovine rotavirus strains (A5, 61A. A44, B223 and KK3). The deduced VP4 amino acid sequence of strain A5 with G8 serotype specificity is 9 1.1% identical to that of strain NCDV of the serotype G6, and strain 6 1A with G10 serotype specificity has a VP4 amino acid sequence (95.2% identity) similar to that of the UK strain of the G6 serotype. In cont rast, the VP4 amino acid sequences of strains A44, B223 and KK3 of the G10 serotype, isolated in Thailand, the U.S.A. and Japan respectively , have very similar sequences to each other, but less similarity (50 t o 60%) to other group A rotavirus strains reported so far. Their VP4 g enes are 2352 nucleotides in length and encode 772 amino acids, four a mino acids fewer than the VP4 proteins of other animal rotaviruses. Th us, the presence of three different VP4 types (P types) and the indepe ndent segregation of G serotype and P type were postulated in bovine r otaviruses by VP4 sequence analysis.